Georgia Rainwater Harvesting Manual
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Georgia Rainwater Harvesting Manual

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Georgia Rainwater Harvesting Manual

Georgia Rainwater Harvesting Manual

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    Georgia Rainwater Harvesting Manual Georgia Rainwater Harvesting Manual Document Transcript

    • GeorgiaRainwaterHarvestingGuidelines In accordance with Appendix I!Rainwater Recycling Systems of the 2009 Georgia Amendments to the 2006 International Plumbing Code
    • Wednesday, April 1, 2009 DRAFT COPY GA RAINWATER GUIDELINES MANUAL 5 Georgia Rainwater Harvesting Guidelines PREFACEThe Georgia Rainwater Harvesting Guidelines are intended to assist all parties involved in the design,construction, inspection and maintenance of rainwater harvesting systems and to help successfully complywith Appendix I-‘Rainwater Recycling Systems’ of the 2009 Georgia Amendments to the 2006 InternationalPlumbing Code (IPC). The parties mentioned above include owners, building officials, design professionalsand contractors. This consensus document is the product of the parties listed below:Guideline Committee Members:Frances Carpenter, chair Bill GuinadeMax Rietschier Marvin RichardsBill Morris Tom CartyErnest U. Earn Bob FreemanDavid Freedman Phillip T. McCreanor, Ph.D.Randy Starr Eddie Van GiesenChris Kumnick Shawn HatleyRyan Meres Frank HenningGreg JeffersThe Guidelines Committee wishes to take this opportunity to express our sincere appreciation to thoseindividuals who donated their time and effort to the development and production of this document. Specialthanks goes out to Eddie Van Giesen and Frances Carpenter for their efforts as principal authors and editorsof this document.Disclaimer and Notice:While the information presented in these guidelines is believed to be correct, the parties involved assume noresponsibility for its accuracy or for the opinions expressed herein. The material presented in this publicationis not considered “Code” and should only be used for reference and guidance in complying with therequirements of Appendix I ‘Rain Water Recycling Systems.’ All rainwater harvesting systems shall complywith the Georgia State Minimum Standard Plumbing Code (2006 IPC with Georgia Amendments) and allother applicable State Minimum Standard Codes for construction. Users of information from this publicationassume all liability arising from such use.The 2009 Georgia Amendments to the International Plumbing Code which contain Appendix I ‘Rain WaterRecycling Systems’ can be downloaded from the Department of Community Affairs website at the followinglink: http://www.dca.ga.gov/development/ConstructionCodes/programs/codeAmendments.asp April 2, 2009 DRAFT for Public Comment 1 of 58 Wednesday, April 1, 2009 DRAFT COPY
    • Wednesday, April 1, 2009 DRAFT COPY GA RAINWATER GUIDELINES MANUAL 7 Georgia Rainwater Harvesting Guidelines TABLE OF CONTENTSFigure 4-12 Corrugated steel tank................................................................................. 11 CHAPTER 1 .................................................................................................... 1 GENERAL INFORMATION .............................................................................1 1.1 Purpose ................................................................................................... 1 1.2 ARCSA .....................................................................................................1 CHAPTER 2 .................................................................................................... 3 INTRODUCTION TO RAINWATER HARVESTING ........................................ 3 2.1 The Big Picture ....................................................................................... 3 2.2 History ..................................................................................................... 5 .................................................................. 6 2.3 Current Usage of Rainwater .............................................................................7 2.4 Response to Drought ................................................................................................. 10 2.5 Benefits .................................................................. 10 2.6 Economics and Feasibility ........................................................................................ 11 2.7 In conclusion .................................................................................................. 12 CHAPTER 3 SYSTEM SIZING AND WATER BALANCING ............................................. 12 3.1 Water Conservation .............................................................................. 12 3.2 Stormwater Runoff Reduction ............................................................. 13 3.3 Green Building ...................................................................................... 14 3.4 System Sizing ........................................................................................ 15 3.5 How Much Water Can Be Captured? ................................................... 16 3.6 Calculating Storage Capacity .............................................................. 18 3.7 Water Conservation Supplemental to Other Resources .................. 20 3.8 Summary ............................................................................................... 20 April 2, 2009 DRAFT for Public Comment 2 of 58 Wednesday, April 1, 2009 DRAFT COPY
    • 8 Wednesday, April 1, 2009 DRAFT COPY GEORGIA RAINWATER GUIDELINES MANUAL Georgia Rainwater Harvesting Guidelines CHAPTER 4 .................................................................................................. 21 HARVESTING COMPONENTS....................................................................21 4.1 Introduction and Fundamental Elements ........................................... 21 4.2 The Catchment Surface ........................................................................ 24 -Metal Roof ................................................................................................... 24 -Clay/Concrete and Tile Roof ..................................................................... 24 -Composite or Asphalt Shingle .................................................................. 25 -Wood Shingle, Tar, and Gravel ................................................................. 25 ............................................................................................................ 25 -Slate ......................................................................................... 25 -Vinyl/rubberized ..................................................................... 25 4.3 Gutters and Downspouts ................................................................... 26 -Gutter Sizing and Installation .................................................................................. 26 4.4 Primary Filtration ...............................................................................................27 -Leaf Screens ......................................................................................27 -Downspout Filters -Strainer Baskets .........................................................................................27 -First-Flush Diverters .................................................................................. 28 4.5 Storage ................................................................................................... 29 -Tank Siting .................................................................................................. 29 4.6 Tank Materials ...................................................................................... 33 -Rain Barrel .................................................................................................. 33 -Above Ground Polypropylene .................................................................. 33 -Fiberglass ................................................................................................... 34 -Below Ground Polypropylene ................................................................... 34 -Metal ............................................................................................................ 36 April 2, 2009 DRAFT for Public Comment 3 of 58 Wednesday, April 1, 2009 DRAFT COPY
    • Wednesday, April 1, 2009 DRAFT COPY GA RAINWATER GUIDELINES MANUAL 9 Georgia Rainwater Harvesting Guidelines -Concrete ..................................................................................................... 36 -Wood ........................................................................................................... 37 4.7 Pumps and Controls ............................................................................ 37 4.8 Treatment and Disinfection .................................................................. 39 CHAPTER 5 .................................................................................................. 40 WATER QUALITY AND TREATMENT COMPONENTS.............................. 40 5.1 Introduction ........................................................................................... 40 5.2 Factors Affecting the Quality of Harvested Rainwater ...................... 40 .................42 5.3 Water Treatment For Non-potable Outdoor Use Systems ....................42 5.4 Water Treatment For Non-potable Indoor Use Systems 5.5 Additional Requirements for Use as Cooling Tower Make Up Water 6 4 ......................................................................................... 46 5.6 Conclusions .................................................................................................. 47 GLOSSARY ................................................................................................... 51 References ...................................................................................................... 52 WebsitesApril 2, 2009 DRAFT for Public Comment 4 of 58 Wednesday, April 1, 2009 DRAFT COPY
    • Wednesday, April 1, 2009 DRAFT COPY GA RAINWATER GUIDELINES MANUAL 11 Georgia Rainwater Harvesting GuidelinesList of FiguresFigure 2.1 Statewide Water Level Restrictions................................................................. 4Figure 2.2 Lake Lanier Level Diagram.............................................................................. 6Figure 2.3 Aerial Photo of Lake Lanier 2007.................................................................... 7Figure 2.4 ! Basic Hydrological Cycle.................................................................................8Figure 2.5 The Hydro-Illogical Cycle................................................................................ 9Figure 3.1 Catchment area of typical roofs...................................................................... 16Figure 4.1 Diagram of above ground cistern................................................................... 21Figure 4.2 Diagram of below ground cistern................................................................... 22Figure 4.3 Rainwater Harvesting Flow Chart.................................................................... 23Figure 4.7 Calming Inlet.................................................................................................. 26Figure 4.5 Downspout filter............................................................................................. 27Figure 4.6 Strainer Basket................................................................................................ 27Figure 4.7 First Flush Diverter.......................................................................................... 28Figure 4.8 Wooden tank.................................................................................................. 30Figure 4.9 Schematic for 350 gallon Rain barrel........................................................ 32Figure 4.10 75 gallon Rain barrel.................................................................................... 33Figure 4.11 Plastic polypropylene tanks.......................................................................... 33Figure 4.12 Below ground Fiberglass tanks..................................................................... 34Figure 4.13 Below ground polypropylene tanks.............................................................. 35Figure 4-14 Corrugated steel tank................................................................................... 36Figure 4.15 Wooden aboveground tank.......................................................................... 37Figure 4.16 Submersible on demand pump with floating suction .................................. 38Figure 4.17 On demand external pump........................................................................... 38Figure 5.1 First flush diverter............................................................................................ 41 April 2, 2009 DRAFT for Public Comment 5 of 58 Wednesday, April 1, 2009 DRAFT COPY
    • Wednesday, April 1, 2009 DRAFT COPY GA RAINWATER GUIDELINES MANUAL 13 Georgia Rainwater Harvesting GuidelinesList of TablesTable 3.1 Percentage of water uses................................................................................... 13Table 3.2 Major GA Cities Annual Precipitation 1971-2000 - 30 year average (inches).... 17Table 3.3 Table for rainwater potential collection from roof surfaces............................. 18Table 4.1 Storage tank materials descriptions.................................................................. 31Table 4.2 Tank volume for a given height and diameter (1,000 GAl units)....................... 32Table 4.3 Typical minimum requirements of commons fixtures in water-harvesting........ 37Table 5.1 Treatment Techniques...................................................................................... 45 April 2, 2009 DRAFT for Public Comment 6 of 58 Wednesday, April 1, 2009 DRAFT COPY
    • Wednesday, April 1, 2009 DRAFT COPY GA RAINWATER GUIDELINES MANUAL 1 Georgia Rainwater Harvesting GuidelinesCHAPTER 1GENERAL INFORMATION1.1 PurposeRainwater, for purposes of this document, is Installers and the general public are advised towater collected from roof surfaces during rain comply with local and state codes.events. This water is then stored in tanks or On January 1, 2009, Appendix I ‘Rainwatercisterns for later use. Potential uses include Recycling Systems’ of the Georgia 2009indoor non-potable applications (toilet Amendments to the 2006 Internationalflushing) and outdoor non-potable applications Plumbing Code took effect allowing rainwater(irrigation systems, hose bibs, etc). Rainwater harvesting in certain applications throughoutHarvesting (RWH) in its essence is the the state. The guidelines presented in thiscollection, conveyance and storage of document (Georgia Rainwater Harvestingrainwater. Rainwater collected from roofs is Guidelines) will assist regulators, rainwaternot “recycled water”, nor is it “gray water”. It systems designers and end users in rainwateris fresh water that is in abundant supply, and is harvesting best management practices. Thegenerally undervalued in the United States. water available from such systems will offer high quality water to supplement utility-Rainwater Harvesting Systems (RWHS) for provided water for approved non-potable endpurposes of this document, are defined as uses.systems that collect, store and use precipitationcollected from rooftops or other man made,above ground collection surfaces. 1.2 ARCSAThe use of rainwater harvesting systems in The American Rainwater Catchment SystemsGeorgia can serve to supplement non-potable Association (ARCSA) is one of the bestwater demands while maintaining and sources of information about rainwater harvesting. ARCSA (www.arcsa.org), anenhancing the quality of the environment. affiliate of the International RainwaterThese guidelines are intended to be consistentwith, and complimentary to, the requirements Catchment Systems Association (IRCSA,of the Georgia’s 2009 Amendments to the 2006 www.ircsa.org ) is an organization formed inInternational Plumbing Code, National Institute 1994 by Dr. Hari J. Krishna in Austin, Texas.of Health, and local Boards of Health. ARCSAs primary mission is to promote rainwater catchment systems in the Americas April 2, 2009 DRAFT for Public Comment 7 of 58 Wednesday, April 1, 2009 DRAFT COPY
    • 2 Wednesday, April 1, 2009 DRAFT COPY GEORGIA RAINWATER GUIDELINES MANUAL Georgia Rainwater Harvesting Guidelinesthrough educational opportunities, theexchange of information at the ARCSA websiteand regularly scheduled workshops andcourses.ARCSA has published guidelines for rainwaterharvesting systems, and is currently writingnational standards for the rainwater harvestingindustry, both of which are available on theirwebsite. Currently Rainwater CatchmentDesign and Installation Standards are beingdeveloped by a joint effort of ARCSA and theAmerican Society of Plumbing Engineers(ASPE). The purpose of these standards is toassist engineers, designers, plumbers, builders/developers, local government, and end users insuccessfully implementing rainwater catchmentsystems. These standards will apply to newrainwater catchment installations, as well asalterations, additions, maintenance and repairsto existing systems.Rainwater harvesting systems can range from asimple 55 gallon rain barrel to a complexmultimillion-gallon cistern with electronicpumps and controls. It is important to evaluateexisting site conditions of the project to ensurecompliance with state and local requirementsduring the planning phase.To assist in understanding the terminology ofRWH, a glossary of commonly used terms isprovided at the end of this document. April 2, 2009 DRAFT for Public Comment 8 of 58 Wednesday, April 1, 2009 DRAFT COPY
    • Wednesday, April 1, 2009 DRAFT COPY GA RAINWATER GUIDELINES MANUAL 3 Georgia Rainwater Harvesting GuidelinesCHAPTER 2INTRODUCTION TORAINWATER HARVESTING2.1 The Big PictureThe Earth’s surface is 75 percent covered by The United States population more than tripledwater; only 3 percent of this water is suitable from 76 million people in 1900 to 281 millionfor human consumption. Of that 3 percent most people in 2000. The population growth of 32.7is either locked in polar caps or hidden beyond million people in the 1990s was the largestthe practical reach of commercial technologies. numerical increase of any decade in U.S.Less than 1 percent of our water is found in history (Hobbs, Frank and Nicole Stoops, U.S. Censuslakes, rivers, and approachable undergroundaquifers. In addition, all freshwater sources are “The city of Tucson, Arizona, onderived from either rainfall or snowmelt. Thiswater then makes its way into the ground, or it Tuesday became the firstflows into inland freshwater bodies or the municipality in the country toocean. Fresh water is a diminishing limited require developers of commercialresource, and though we cannot increase the properties to harvest rainwaterEarth’s supply of water, we can manage what for landscaping. The new water-supplies we have more effectively. saving measure - approved by aGlobal consumption of water has been unanimous vote by the Citydoubling every 20 years, more than twice the Council -- mandates that newrate of human population growth. We are using developments meet 50 percent ofwater as if it is an infinite resource, but it’s not. their landscaping waterWe are in fact depleting our planet’s usable requirements by capturingwater supply. Shrinking fresh water suppliespresent the most urgent and potentially rainwater. The new rule goes intocatastrophic environmental problem today effect June 1, 2010.” http://worldwide (Barlow, 2002). www.biologicaldiversity.org/ news/center/articles/2008/land- letter-10-16-2008.html. April 2, 2009 DRAFT for Public Comment 9 of 58 Wednesday, April 1, 2009 DRAFT COPY
    • 4 Wednesday, April 1, 2009 DRAFT COPY GEORGIA RAINWATER GUIDELINES MANUAL Georgia Rainwater Harvesting Guidelines Figure 2.1 Statewide Water Level RestrictionsBureau, Census 2000 Special Reports, Series CENSR-4, Excluding agriculture, one estimate forDemographic Trends in the 20th Century, U.S. Georgia’s average daily per-capita waterGovernment Printing Office, Washington, DC, 2002). consumption is estimated at 168 gallonsStatewide (Georgia) public-supply water use compared with a national average of 153has increased steadily since 1980, gallons. Steps need to be taken to ensure thatcorresponding to an increase in population Georgia’s water supply continues to meet theduring the same period.” “Water use for public needs of the economy (Dodd, http://supply likely will continue to increase as the www.gppf.org/article.asp?RT=20&p=pub/Water/ envwateruse040528.htm).S t a t e ’s p o p u l a t i o n g r o w s . ” ( h t t p : / /ga.water.usgs.gov/pubs/other/ggs-ic106/pdf/ggs- Rainwater harvesting systems address manyic106.pdf). water issues associated with population growth April 2, 2009 DRAFT for Public Comment 10 of 58 Wednesday, April 1, 2009 DRAFT COPY
    • Wednesday, April 1, 2009 DRAFT COPY GA RAINWATER GUIDELINES MANUAL 5 Georgia Rainwater Harvesting Guidelinesand urban expansion,, such as reduced public and building new pipelines and associatedwater consumption improved stormwater technologies (Texas Manual, 2006).quality and increased soil infiltration.We all use rainwater either directly or Rainwater harvesting can be envisioned asindirectly. Water from a municipal source, an relieving, not replacing, some of the burdenexample of an indirect use of rainwater, comes placed on the existing public utilities especiallyfrom a spring or reservoir fed by rainfall and during times of drought and high demand.snowmelt, the ultimate suppliers of thesesources. Because the water runs across parking 2.2 Historylots and highways, through fields that may The collection and use of rainwater is not new.have been treated by pesticides, down storm Long before centralized water delivery andgutters, and into the lakes and streams, the treatment systems were built, our ancestorsmunicipal water authority has to treat the water knew that access to water was a basic necessitywith chemicals to kill pathogens and correct for for survival. Archeological evidence of RWHpH. Rainwater harvesting, an example of a techniques date back at least 4,000 years. Ruinsdirect use of rainwater, is not exposed to the of cisterns have been found in Israel, believedsame pollutants and therefore does not require to be from 2,000 BC. The concept of rainwaterthe same level of treatment as water which harvesting may date back 6,000 years (Gouldflows overland and underground before it’s and Nissen-Peterson 1999).collected. Public utilities have the addedburden of maintaining existing supply and In the 20th century, large-scale public waterstormwater infrastructure as well as designing systems were developed in industrialized During a Level 4 drought, virtually all outdoor water use is prohibited. A Level 4 drought is an “extreme drought,” with lake levels, stream flows and rainfall at or approaching the lowest levels in 100 years. In Georgia, a Level 4 drought was declared in 2007 for the northern third of the state, including the metropolitan Atlanta area. The declaration was made because rainfall in this portion of the state was more than 20 inches below normal (see http://www.caes.uga.edu/topics/disasters/drought/ totalrainfallmap .html) in 2007 and 2008, and stream flows were far below normal across the state. April 2, 2009 DRAFT for Public Comment 11 of 58 Wednesday, April 1, 2009 DRAFT COPY
    • 6 Wednesday, April 1, 2009 DRAFT COPY GEORGIA RAINWATER GUIDELINES MANUAL Georgia Rainwater Harvesting Guidelines Figure 2.2 Lake Lanier Level Diagramcountries and RWH became restricted to IRCSA to promote and advance rainwaterspecialized applications and regions, such as on catchment systems technology.small islands and in semi-arid rural areas of theworld. Law in the U.S. Virgin Islands and 2.3 Current Usage ofmany other Caribbean Islands requires RWHdue to limited fresh water sources. Interest in RainwaterRWH in the United States and around the globe There may be as many as 250,000 RWHhas grown significantly in recent years due to systems in use in the United States (Kincade,d r o u g h t s a n d w a t e r s h o r t a g e s . RW H 2007). Texas, Virginia, Oregon, the state ofassociations are forming in countries all over Washington, and other states have developedthe world and many are now joining together in guidelines for designing and installing April 2, 2009 DRAFT for Public Comment 12 of 58 Wednesday, April 1, 2009 DRAFT COPY
    • Wednesday, April 1, 2009 DRAFT COPY GA RAINWATER GUIDELINES MANUAL 7 Georgia Rainwater Harvesting Guidelinesrainwater harvesting systems. In Hawaii, up to now source their water from rainwater tanks.60,000 people depend on RWH systems for Countries such as Germany, Australia, Newtheir water needs (Macomber, 2001). In India, Zealand, Great Britain, Sri Lanka, India,since June 2001, the Ministry of Urban affairs Pakistan and othersand Poverty Alleviation has made rainwater are considerably farther along in theirharvesting mandatory in all new buildings with understanding and regulation of the use ofa roof area of more than 100 square meters and rainwater. In some instances both local andin all plots with an area of more than 1,000 national authorities insist on designed andsquare meters, that are being developed (http:// installed rainwater catchment systemsw w w. r a i n w a t e r h a r v e s t i n g . o r g / U r b a n / integrated into new developments.Legislation.htm). In the United States somemunicipalities require RWH systems in new 2.4 Response to Droughtdevelopments. Tucson, Arizona recently passed By August 2000, 36 percent of the Unitedthe nation’s first rainwater harvesting States was in severe to extreme drought,ordinance for commercial properties. Currently leading to widespread wildfires and othermore than 10 percent of New Zealanders rely drought-related damages (Natl Oceanic andon rainwater for their drinking needs (Abbott, A tmospheric Administration Climate of 2000 - September, U.S. Drought National Climatic Data Center, 16 October2008). In Australia 17 percent of households Figure 2.3 Aerial Photo of Lake Lanier 2007 April 2, 2009 DRAFT for Public Comment 13 of 58 Wednesday, April 1, 2009 DRAFT COPY
    • 8 Wednesday, April 1, 2009 DRAFT COPY GEORGIA RAINWATER GUIDELINES MANUAL Georgia Rainwater Harvesting Guidelines2000 (National Oceanic and Atmospheric Administration, there will always be a supply of clean water in .2001; U.S. Department of Agriculture, 2000) Georgia and in our region as a whole. Recent drought conditions in the Southeast and in Georgia in particular have triggered manyAccording to David Stookesbury, state municipalities and governing bodies to placeclimatologist for the state of Georgia, the water restrictions on the use of municipal waterperiod between WWII and the late 1970s was ( F i g u r e 2 . 1 , S t a t e w i d e Wa t e r L e v e lan abnormally benign climatic period. Since Restrictions). In some instances outdoorthe late 1970s we returned to a more normal watering has been banned completely. Evenclimate pattern that involves greater year-to- more alarming is the possibility ofyear variability in temperature and rainfall. For implementing contingency plans for prioritizedcity planners, public water authorities and the use of municipal water supplies. RWH hasagriculture industry, this means increased great potential for supplying water for variousdifficulty in planning. uses in the midst of these restrictions.It has generally been taken for granted that Figure 2.4 Basic Hydrological Cycle April 2, 2009 DRAFT for Public Comment 14 of 58 Wednesday, April 1, 2009 DRAFT COPY
    • Wednesday, April 1, 2009 DRAFT COPY GA RAINWATER GUIDELINES MANUAL 9 Georgia Rainwater Harvesting Guidelines Figure 2.5 The Hydro-Illogical CycleThe city of Atlanta derives most of its water boundary between Georgia and Tennessee hasfrom Lake Lanier. In December 2008, lake been recently disputed over water rights in thelevels were near the all time low (Figure 2.2, Tennessee River. The aerial view of drought-Lake Lanier Level Diagram). As difficult as stricken Lake Lanier (Figure 2.3, Aerial Photothis is to imagine, there is a finite amount of of Lake Lanier, 2007) makes it clear thatwater in the lake. Once the water level goes actions must be taken to address water suppliesbelow the level of the intakes, there is no way in our State.to extract any more water until the lake isreplenished by additional rains, or until the Water conservation is in the minds of many ofintake is lowered, which could require our citizens and policy makers. Unlike otherdredging and large capital outlays. natural disasters, drought does not have a clearly defined beginning and end. As a result,Water rights and water availability are our reaction to drought traditionally has notimportant and relevant topics today. Politics, been timely. It is human nature to think thatindustrial interests, and environmental just because it rained yesterday that the droughtconcerns all play into this picture. The state is over. This is largely due to widespread lack April 2, 2009 DRAFT for Public Comment 15 of 58 Wednesday, April 1, 2009 DRAFT COPY
    • 10 Wednesday, April 1, 2009 DRAFT COPY GEORGIA RAINWATER GUIDELINES MANUAL Georgia Rainwater Harvesting Guidelinesof understanding of the basic hydrological • RWH is by nature decentralized andcycle (Figure 2.4, Basic Hydrological Cycle relatively less vulnerable to naturalNational Drought Mitigation Center, disasters than public water supplies.University of Nebraska, Lincoln, Nebraska, • Harvested Rainwater is low inUSA). minerals and it is ideal for activities such as car washing. Since itPublic attention tends to wane after significant contains no chlorine, rainwater israin events and sometimes after small ones. also ideal for filling garden pondsThe cartoon in Figure 2.5, The Hydro-Illogical and irrigating sensitive plants.Cycle, cleverly illustrates the point that • Widespread adoption of rainwaterappearances can be deceiving. harvesting can increase the efficiency of expensive water2.5 Benefits supply infrastructure.Given the variability in the amounts and timingof rainfall received, collecting water when it 2.6 Economics andcomes in abundance for use at a later time islogical and sustainable. Integrating rainwater Feasibilityharvesting concepts into new construction Municipal water is generally purchased atdesign generally does not present relatively low rates throughout the state.overwhelming problems. Retrofitting most According to EPA region 4 Environmentalbuildings to collect the rainwater that is Finance Center, the median monthly amountordinarily piped away is a relatively simple charged for minimum usage of water is $10.00,procedure. In many cases, the gutters, $20.50 for 6,000 gallons, and $29.50 fordownspouts and pipes are already present on 10,000 gallons. As a point of comparison, athe building. gallon of potable water at a major groceryThe numerous benefits and advantages in retailer is $1.20 per gallon while the medianharvesting rainwater include the following: bill for 6,000 gallons is $0.0034 per gallon • Rainwater is free. Although its which is approximately 350 times cheaper initial equipment installation costs (http://www.efc.unc.edu/publications/pdfs/ can be significant, long-term costs GA2007WaterSewerRatesReport.pdf). are workable, given our circumstances. For most Georgians, spending significant • Stored rainwater gives its owner amounts of money on a RWH system is low on more independence from the effects the priority list. When calculating the of irregularities of rain events. “payback” for a residential or commercial rain harvesting system, costing in the thousands of April 2, 2009 DRAFT for Public Comment 16 of 58 Wednesday, April 1, 2009 DRAFT COPY
    • Wednesday, April 1, 2009 DRAFT COPY GA RAINWATER GUIDELINES MANUAL 11 Georgia Rainwater Harvesting Guidelinesdollars, often the investment cannot be justified pressure on municipal and private waterbased only on the relatively cheap cost of supplies. Understanding how to implementmunicipal water. Perhaps it makes more sense these technologies is key in rainwaterto think in terms of the overall ecological harvesting as a viable safe supplement to abenefit gained from reducing demands on shrinking water supply.public fresh water supplies.For some individuals the satisfaction ofcatching the rain is motivation enough. Freshwater demands from ground sources (wells),both public and private can also be reduced byusing rainwater. It is worth pointing out that insome instances, the only thing preventing theloss of an established landscape during periodsof outdoor watering restrictions is a RWHsystem. For some residents, having the peaceof mind that their new or existing landscapewill survive and thrive is the only motivationneeded to install a RWH system. In the case ofsome businesses in some municipalities in theSoutheastern US, the ability to remain inbusiness has depended on a functioning RWHsystem.2.7 In conclusionWorldwide freshwater shortages clearlyindicate that immediate action must be taken toimplement RWH technologies. RainwaterHarvesting has been practiced since ancienttimes. We know from history that local andregional droughts occur on a regular basisthroughout the world. We also know that manythousands of RWH systems exist throughoutthe US and that when they are properlydesigned and installed they are able to providemany benefits, most immediately to alleviate April 2, 2009 DRAFT for Public Comment 17 of 58 Wednesday, April 1, 2009 DRAFT COPY
    • 12 Wednesday, April 1, 2009 DRAFT COPY GEORGIA RAINWATER GUIDELINES MANUAL Georgia Rainwater Harvesting GuidelinesCHAPTER 3SYSTEM SIZING ANDWATER BALANCINGRWH systems can range from the very simple public commercial buildings, educationalto the very complex. It is absolutely facilities and homes. For example, the Energyfundamental to determine the reasons for Policy Act of 1992 requires that from Januarycollecting rainwater prior to designing any 1994 onward all toilets sold in the Unitedsystem. There are many reasons for wanting to States use no more than 1.6 gallons of waterhave a RWH system; however, three of the per flush, well below the 3.5 gallons per flushmost important reasons are: used by most American toilets (Energy Policy Act of 1992. Public Law 102486, 102nd Congress. • Wa t e r c o n s e r v a t i o n a n d Washington, D.C. Oct. 24, 1992 http://www.cepis.ops- supplemental water supply; oms.org/muwww/fulltext/repind48/energy/energy.html). • Storm water reduction; and • Achieving Green building goals. Georgia’s average daily per-capita water consumption, excluding agriculture, isExamining these three areas (water estimated at 168 gallons compared with aconservation, stormwater runoff reduction, and national average of 153 gallons. Only oneGreen building) helps focus on the benefits of percent of this water is used for drinkingcollecting rainwater and establishes specific purposes (Benita Dodd, Georgia Public Policyparameters in designing a rainwater system. If Foundation (May 28, 2004), http://www.gppf.org/a project must be 20 percent more water default.asp?pt=news&RT=20). Even during timesefficient or must reduce site runoff by 60 of drought there is plenty of rainfall in Georgiapercent, a specific goal has been established for that can be harvested and used to supplementassistance in determining the type and size of the demands for non-potable purposes such asthe rainwater system required to meet these landscape watering, toilet and urinal flushing,project objectives. and cooling tower makeup. Water used for non-potable purposes does not3.1 Water Conservation require the same level of treatment as waterConservation practices are those that help us that must meet EPA drinking water qualityextend the usefulness of a specific resource. standards. In order to safely serve these needs,Water conservation makes good economic this water must have, however, appropriatesense and is sometimes law for private and quality. See Chapter 5 for more information on water quality. April 2, 2009 DRAFT for Public Comment 18 of 58 Wednesday, April 1, 2009 DRAFT COPY
    • Wednesday, April 1, 2009 DRAFT COPY GA RAINWATER GUIDELINES MANUAL 13 Georgia Rainwater Harvesting Guidelines USE GALLONS PER % OF DAILY TOTAL CAPITA POTABLE INDOOR USES: Showers 11.6 7% Dishwashers 1 0.60% Baths 1.2 0.80% Faucets 10.9 6.60% Other uses, leaks 11.1 6.70% Subtotal potable indoor uses 35.8 21.70% NON-POTABLE INDOOR USES: Clothes washers(Non permissable per 15 9.10% code in GA) Toilets 18.5 11.20% Subtotal non-potable indoor uses 33.5 20.30% NON-POTABLE OUTDOOR USES 95.7 58% Table 3.1 Percentage of water uses3.2 Stormwater Runoff soak into the ground as close to the location where it falls, is another goal of LID. A RWHReduction system can act as a large sponge, absorbing andLow Impact Development (LID) is a design storing water for later use. The water can thenand site development methodology that allows be released at a slower rate via landscapenewly developed and/or existing sites to watering.hydrologically mimic pre-developmentconditions. For example, if a forested area is Stormwater retention requirements can bedeveloped for commercial purposes, one LID partially achieved by incorporating RWH as angoal would be to mimic some of the integral part of the design (http://hydrological functions of trees and encourage www.lowimpactdevelopment.org/). From 1991 tocleansing and infiltration of site rainwater 2005 the state of Georgia has had an increaserunoff. Capturing rain and encouraging it to of 111% in the amount of impervious surface, April 2, 2009 DRAFT for Public Comment 19 of 58 Wednesday, April 1, 2009 DRAFT COPY
    • 14 Wednesday, April 1, 2009 DRAFT COPY GEORGIA RAINWATER GUIDELINES MANUAL Georgia Rainwater Harvesting Guidelinesincreasing its impervious area from 216,805 3.3 Green Buildingacres to 455,337 acres (Natural Resources Spatial With the growing awareness of the need toAnalysis Laboratory, College of Agricultural and reduce our footprint on the environment, a newEnvironmental Sciences, UGA http://narsal.uga.edu/ movement toward a more conscious,glut/ecoregion.php?ecoregion=5). In urban areas sustainable and wise development has beenacross the state, rain dubbed “Green.”falls on a roof surface, Many buildingtravels through a gutter/ The National Green Building organizations havepiping network, and Standard offers the following points programs witheventually arrives as for rainwater collection:  rating systems forstormwater into a creek new developments,or river. Impervious 801.11 Rainwater collection and homes andsurfaces force water to distribution. commercialflow rapidly through buildings. Thesestormwater systems and (1)Rainwater is collected and rating systems arethus overwhelm creek used: 6 points based inand stream banks, sustainabilitycausing ongoing (2)Rainwater is distributed using a s t a n d a r d s .ecological degradation. renewable energy source or R a i n w a t e r gravity: 2 points harvesting canUnfortunately in some assist in achievingurban environments in Courtesy of NAHB 2009 the desired level ofGeorgia, sewage and (National Association of Home "Green." Forstormwater still flow in example, thethe same pipe networks. Builders) N a t i o n a lDuring particularly w w w. n a h b r c . o r g / t e c h n i c a l / s t a n d a r d s / Association ofheavy rain events, raw gbversion1_chapter08.pdf Home Buildersuntreated sewage may (NAHB) has abe carried directly into program thatcreeks and streams. awards points for integrating a RWH systemHarvesting some of the rainwater before it into the construction of new homes. NAHB,enters the stormwater drainage system can help the International Code Council (ICC) and thereduce peak flow volumes during these rain NAHB Research Center have initiated aevents and therefore lessen the environmental process for the development of an ANSIimpacts of these combined systems. standard for Green home building construction April 2, 2009 DRAFT for Public Comment 20 of 58 Wednesday, April 1, 2009 DRAFT COPY
    • Wednesday, April 1, 2009 DRAFT COPY GA RAINWATER GUIDELINES MANUAL 15 Georgia Rainwater Harvesting Guidelines Harvested Water (gal) = catchment area (sq.ft.) X depth (in.) X 0.623 (conversion factor) A simple estimate of the number of gallons that can be harvested from a given catchment area after a rainfall event can be determined with the following formula. The total number of gallons harvested is equal to the catchment area (square feet) times the depth of a rainfall (inches) times a conversion factor of 0.623.practices, which is titled The National Green for a total of 41 consecutive dry days, a recordBuilding Standard™ ( http://www.nahbrc.org/ in the state (http://www.ncdc.noaa.gov/oa/climate/technical/standards/gbinvitation.aspx). extremes/2000/october/octoberext2000.html).Selecting materials for rainwater systems basedon locally available components and equipment Rainfall is fairly evenly distributed throughoutcontaining recycled content may achieve the year in the state of Georgia. This evenfurther credit. distribution enables storage capacity to be somewhat less than in other areas of the3.4 System Sizing country (arid southwestern states) where rainfall occurs more seasonally (longer periodsA basic goal for sizing any rainwater of time between rain events). Storage capacityharvesting system is to balance the volume of needs to be sufficient to store water collectedwater that can be captured and stored (supply), during heavy rain events to last through drycompared to the volume of water used periods. Some residences might be constrained(demand). In order to “balance” the system, the by the size of the collection surfaces and/or thesupply must equal or exceed the demand. This volume of storage capacity that can be installedis easiest to understand if broken down on a due to space or costs. The following sectionsmonthly basis. describe ways to determine the amount of rainfall, the estimated demand, and how muchIn Georgia, the longest anticipated period storage capacity is needed to provide enoughbetween rain events is normally less than 30 rainwater to meet the demand. The rainfall datadays. However, no measurable rain fell from for selected Georgia cities is found in TableSeptember 25th through November 4th, 2000 3.2, Major Georgia Cities Annual Precipitation. April 2, 2009 DRAFT for Public Comment 21 of 58 Wednesday, April 1, 2009 DRAFT COPY
    • 16 Wednesday, April 1, 2009 DRAFT COPY GEORGIA RAINWATER GUIDELINES MANUAL Georgia Rainwater Harvesting Guidelines Note: It is important to understand that regardless of the pitch, the shape, or the complexity of any roof surface, it is the overall footprint of the building that determines the collection area. (see Figure 3.1)Figure 3.1 Catchment area of typical roofs3.5 How Much Water CanBe Captured? surface is the area covered by collection surface (length times width of the roof fromApproximately 0.62 gallons per square foot of eave to eave and front to rear). Obviously, ifcollection surface per inch of rainfall can be only one side of the structure is guttered, onlycollected during a rain event. Some rainwater the area drained by the gutters is used in theis lost to first flush (see components, see calculation. For commercial buildings refer toglossary), evaporation, splash-out or overshoot the plumbing code for additional sizingfrom the gutters in hard rains, and possible requirements.leaks. Rough collection surfaces are lessefficient at conveying water, as some of the •Rainfall Distributionwater captured on porous surfaces tends to be According to the Georgia State Climatologylost to evaporation. A much more in depth Office, average annual rainfall in Georgiaanalysis of how to calculate potential harvested varies from a low of about 40 inches inrainwater is available through the ARCSA Montgomery County to a high of over 80website (http://www.arcsa.org/resources.html) inches in isolated mountainous areas in thein their guidelines publication. northeastern part of the state. If the rainwater harvesting system is intended to be the sole•Collection Surface water source for a specific use, the catchmentThe collection surface is the “footprint” of the area and storage capacity must be sized to meetroof. In other words, regardless of the pitch or the water demand through the longest expectedshape of the roof, the effective collection April 2, 2009 DRAFT for Public Comment 22 of 58 Wednesday, April 1, 2009 DRAFT COPY
    • Wednesday, April 1, 2009 DRAFT COPY GA RAINWATER GUIDELINES MANUAL 17 Georgia Rainwater Harvesting Guidelines City JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC TOTAL ATLANTA 5.03 4.68 5.38 3.62 3.95 3.63 5.12 3.67 4.09 3.11 4.10 3.82 50.20 ATHENS 4.69 4.39 4.99 3.35 3.86 3.94 4.41 3.78 3.53 3.47 3.71 3.71 47.83 MACON 5.00 4.55 4.90 3.14 2.98 3.54 4.32 3.79 3.26 2.37 3.22 3.93 45.00 COLUMBUS 4.78 4.48 5.75 3.84 3.62 3.51 5.04 3.78 3.07 2.33 3.97 4.40 48.57 SAVANNAH 3.95 2.92 3.64 3.32 3.61 5.49 6.04 7.20 5.08 3.12 2.40 2.81 49.58 AUGUSTA 4.95 4.11 4.61 2.94 3.07 4.09 4.07 4.48 3.59 3.20 2.68 3.14 44.58 VALDOSTA 5.79 4.47 5.30 3.61 3.15 4.91 6.30 5.24 4.11 3.11 3.24 3.83 53.06 Table 3.2 Major GA Cities Annual Precipitation 1971-2000 - 30 year average (inches) NOAA – National Weather Service Forecast Office, www.srh.noaa.gov Weather Channel, www.weather.cominterval without rain. If additional water is precipitation ranges from 3.4 inches inrequired, other water sources must be November to 5.3 inches in July. The monthlyconsidered to supplement the collected distribution of rainfall is an important factor torainwater. consider for sizing a system.Some rainfall collected from high-intensity, • Monthly Rainfall Estimationshort-duration rain events, may be lost to Rainfall estimates should always be preparedoverflow from storage tanks or splash out from for a specific locale, using the best data thatthe gutters. Since these intense rainfall events apply to that area. Two different estimators ofare considered part of the cumulative annual monthly rainfall are commonly used: averagerainfall, the total available volume of such an rainfall and median rainfall. Taking the sum ofevent is rarely captured. historical rainfall and dividing by the numberAnother consideration is that annual rainfall is of years of recorded data calculates averagenot evenly distributed throughout the twelve annual rainfall. Information on rainfall data ismonths of the year. Statewide average monthly available from numerous public sources, April 2, 2009 DRAFT for Public Comment 23 of 58 Wednesday, April 1, 2009 DRAFT COPY
    • 18 Wednesday, April 1, 2009 DRAFT COPY GEORGIA RAINWATER GUIDELINES MANUAL Georgia Rainwater Harvesting Guidelines Rainfall Area X Gallons/Sq. Total Gallons (in.) (Sq. Ft.) Ft. 1 2,200 0.62 1,364.00 5 2,200 0.62 6,820.00 10 2,200 0.62 13,640.00 40 2,200 0.62 54,560.00 50 2,200 0.62 68,200.00 1 3,500 0.62 2,170.00 5 3,500 0.62 10,850.00 10 3,500 0.62 21,700.00 40 3,500 0.62 86,800.00 50 3,500 0.62 108,500.00 1 5,000 0.62 3,100.00 5 5,000 0.62 15,500.00 10 5,000 0.62 31,000.00 40 5,000 0.62 124,000.00 50 5,000 0.62 155,000.00 Table 3.3 Table for rainwater potential collection from roof surfacesincluding the National Climate Data Center 3.6 Calculating Storagewebsite (NOAA, Climatography of the UnitedStates No. 85, Section 2: Precipitation.NCDC: Capacity* National Climatic Data Center (NCDC).* Once the potential for rainfall capture volumeMedian rainfall is the amount of rainfall that is known from rainfall data and catchmentoccurs in the midpoint of all historic rainfall area, the next step is to calculate storagetotals for any given month. In other words, capacity. The decision of whether rainwaterhistorically for the month in question, half of will be used for irrigation, non-potablethe time the rainfall was less than the median domestic use, or both, will factor into howand half of the time rainfall was more than the much water will be used, thus dictating watermedian. demand. April 2, 2009 DRAFT for Public Comment 24 of 58 Wednesday, April 1, 2009 DRAFT COPY
    • Wednesday, April 1, 2009 DRAFT COPY GA RAINWATER GUIDELINES MANUAL 19 Georgia Rainwater Harvesting Guidelines American Water Works (AWWA) ResearchIf a rainwater harvesting system is to be the Foundation. Of this amount, 42 percent is usedsole water supply for a set of specific uses, indoors, and the remaining 58 percent is usedoverbuilding ensures a safety margin. If budget outdoors. By far the largest percentage ofconstraints do not allow the user to install as indoor water use occurs in the bathroom formuch storage capacity as a sizing method toilet flushing (18.5 gal/person/day) andindicates, it is important to provide an area showering (11.6 gal/person/day). Clotheswhere additional tanks or cisterns can be washers were the second largest water usersinstalled at a later date when finances permit (15 gal/person/day).(Texas Manual, 2006). A simple method for most residences of estimating outdoor irrigation demand is•Monthly Demand and Supply analyzing the water bill and comparing waterOne method of determining the feasibility of a usage between the summer and winter months.proposed system is the monthly water balance If water is used for landscape and gardening,method. This method of calculation is similar there will typically be a spike in volume used.to maintaining a monthly checkbook balance. The difference between the summer and winterStarting with an assumed volume of water months will typically be the monthly outdooralready in the tanks, the volume captured each usage. It is shocking to many people when theymonth is added to the previous balance and the discover the vast volume of water that is usedmonthly demand is subtracted. The initial to water lawns.volume of water in the tanks would beprovided by hauling or capturing water prior to •Estimating Indoor Water Demandwithdrawing water from the system. Data and Currently the only approved application ofcalculations can be entered on an electronic rainwater in Georgia for indoor purposes arespreadsheet to enable the user to compare toilet and urinal flushing and cooling towerdifferent variables of catchment area and make-up. Although a number of states havestorage. It is suggested that perspective system approved rainwater for use in automatic clothesowners experiment with different variables of washers (washing machines), this is notstorage capacity and, if applicable, catchment permissible in Georgia.surface to find the desired level of comfort andaffordability for catchment size and storage Most American families flush the toilet ancapacity. average of 4 times per day per person. Calculating 1.6 gallons per flush, a family of•Estimating Demand four will use approximately 25.6 gallons perNorth American households use approximately day or a total of 768 gallons per month. If toilet146,000 gal of water annually, according to the flushing will be the sole usage of rainwater for April 2, 2009 DRAFT for Public Comment 25 of 58 Wednesday, April 1, 2009 DRAFT COPY
    • 20 Wednesday, April 1, 2009 DRAFT COPY GEORGIA RAINWATER GUIDELINES MANUAL Georgia Rainwater Harvesting Guidelinesa household, then planning for 30 days withminimal or no rain, would require a storagetank of at least 768 gallons, or the next closestsize (AWWA http://www.cepis.ops-oms.org/muwww/fulltext/repind48/energy/energy.html).3.7 Water ConservationSupplemental to OtherResourcesIt is impossible to separate water conservationfrom system sizing, because the water demanddetermines the system size. Consciouslyconserving water (water-conserving plumbingfixtures, shorter showers, less outdoorirrigation, etc.) decreases the total demand.This results in more efficient use of ourresources and enables us to do more with whatwe already have. For information on residentialwater efficiency, visit the Water Saver Homew e b s i t e ( w w w. h 2 o u s e . o rg ) , a v i r t u a lencyclopedia of water-saving tips, andAWWA’s drinktap.org consumer website.3.8 SummaryRainfall events are complicated and an indepthunderstanding of local rainfall is imperative.Those comtemplating designing or installing aRWH system should have an adequate amountof rainfall data, in order to properly size theirsystem (ARCSA GUIDE 2009, Chapter 8). April 2, 2009 DRAFT for Public Comment 26 of 58 Wednesday, April 1, 2009 DRAFT COPY
    • Wednesday, April 1, 2009 DRAFT COPY GA RAINWATER GUIDELINES MANUAL 21 Georgia Rainwater Harvesting GuidelinesCHAPTER 4HARVESTINGCOMPONENTS4.1 Introduction andFundamental ElementsRainwater harvesting is the capture, diversion, installing a RWH (See figure 4-3, Rainwaterand storage of rainwater for a number of Harvesting Flow Chart).different purposes including landscapeirrigation, non-potable domestic use, aquifer Rainwater systems are available in manyrecharge, and storm water abatement. configurations. Some have below groundUnderstanding how the fundamental storage tanks, above ground tanks, indoorcomponents of a rainwater system work is controls, and some have outdoor controls.crucial when contemplating designing or Figures 4.1 and 4.2 illustrate the primary Figure 4.1 Diagram of above ground cistern April 2, 2009 DRAFT for Public Comment 27 of 58 Wednesday, April 1, 2009 DRAFT COPY
    • 22 Wednesday, April 1, 2009 DRAFT COPY GEORGIA RAINWATER GUIDELINES MANUAL Georgia Rainwater Harvesting Guidelines Figure 4.2 Diagram of below ground cisterncomponents of each type. If the end use isindoors for toilet and urinal flushing, or for • Gutters and downspouts: conduits thatcooling tower make-up, treatment components channel water from the roof to the tank.are included as well. • Downspout filtration, leaf screens, first-flush diverters, and roof washers: components thatMany factors influence component selection remove debris and dust from the capturedwhen designing or selecting the right rainwater rainwater before it goes to the tank.system for a specific end use application. • Storage: one or more storage tanks, alsoGutters, downspouts, buried utilities, soil types, called cisterns.soil depths, slopes, site drainage, existing • Pumps and controls: devices such as levelplumbing, electricity, diversion of overflows, indicators, makeup water supplies, back flowlocal restrictions, neighborhood covenants, and preventers and or air gaps.neighbors are some of the many items that • Treatment and disinfection: for non-potabledeserve attention when siting RWH systems. indoor systems, filters and other methods toRegardless of the complexity of the system, make the water suitable for use in toiletrainwater harvesting systems are comprised of flushing, urinal flushing and as cooling towersix basic elements: make-up. April 2, 2009 DRAFT for Public Comment 28 of 58 Wednesday, April 1, 2009 DRAFT COPY
    • Wednesday, April 1, 2009 DRAFT COPY GA RAINWATER GUIDELINES MANUAL 23 Georgia Rainwater Harvesting Guidelines RAINWATER HARVESTING FLOW CHART Catchment Surface First flush Inlet Filtration Calming Inlet Back flow Prevention Storage Make up supply Vector Overflow Municipal or well Prevention Air Gap Distribution Pumps, controls, etc Filtration Indoor Use Outdoor Use Disinfection Sediment Evaporative Toilets and Outdoor Cooling Urinals Irrigation, Hose bib Figure 4.3 Rainwater Harvesting Flow ChartApril 2, 2009 DRAFT for Public Comment 29 of 58 Wednesday, April 1, 2009 DRAFT COPY
    • 24 Wednesday, April 1, 2009 DRAFT COPY GEORGIA RAINWATER GUIDELINES MANUAL Georgia Rainwater Harvesting Guidelines4.2 The CatchmentSurfaceThe roof of a building or house for purposes of Condensatethis document is the only choice for the While technically not originatingcatchment surface. Water quality from different from a roof surface, condensateroof catchment surfaces is a function of the from air-conditioningtype of roof material, climatic conditions, andthe surrounding environment (Vasudevan, (dehumidification) units2002). Common sense should prevail in collectively represents adeciding whether or not to collect water from a significant source of water in bothparticular surface. Care should be taken inconsidering how certain roofing materials that residential and commercialcome in direct contact with rainwater affect its applications. The amount of waterquality. Once again, the end use will ultimately that can be collected from anydetermine the viability of a given surface. The given indoor environment variesmajor roof surface types commonly found inGeorgia are listed below. greatly, depending on seasonal climatic conditions, HVAC-Metal Roof equipment and building size. FiveThe surface texture affects the quantity of to twenty-five gallons per day canrainwater that can be collected from a given be collected from many singleroof, the smoother the better (Texas Manual,2006). Powder coated steel is one of the best family residences. Significantlysurfaces to consider. It is very smooth and larger volumes can be collected inwater sheds off it easily during rain events. In commercial applications. Thisaddition, it resists corrosion for extended condensate water can be routedperiods of time. Although relatively moreexpensive than other roof materials, metal either by gravity flow, or with theroofs will outperform most other types over aid of a condensate sump pumptime. directly to the rainwater storage tank.-Clay/Concrete and Tile RoofClay and concrete tiles are both porous. Thesematerials contribute to as much as a 10 percent April 2, 2009 DRAFT for Public Comment 30 of 58 Wednesday, April 1, 2009 DRAFT COPY
    • Wednesday, April 1, 2009 DRAFT COPY GA RAINWATER GUIDELINES MANUAL 25 Georgia Rainwater Harvesting Guidelinesloss due to texture, inefficient flow, or -Slateevaporation. To reduce water loss, tiles can be Slate’s smoothness makes it ideal for apainted or coated with a sealant. There is some catchment surface. However, costchance of toxins leaching from the tile sealant consideration may preclude its use.or paint, but this roof surface is safer whencoated with a special sealant or paint to prevent -Vinyl/rubberizedbacterial growth on porous materials. The There are many new roofing materials on thepotential for chemical leaching should be market today primarily used in commercialconsidered if the water will be used for construction. These materials typically havelivestock, fish ponds, or other end uses with thermally or chemically welded seams. Checkspecial water quality considerations (Texas with the roofing material manufacturer forManual, 2006). suitability as a collection surface.-Composite or Asphalt ShingleThe vast majority of residential roof surfaces in 4.3 Gutters andthe United States are made of composite Downspoutsasphalt shingles. For applications discussed in Rood gutters direct the flow of rainwaterthis guide, i.e., non-potable indoor use and running off the eaves of a building. Someoutdoor irrigation, there is little evidence tosuggest serious detrimental water quality gutter installers can provide continuous orimpacts resulting from rainwater from this type seamless gutters. The most common materials for gutters and downspouts are half-roundof surface. Cistern water should be protected PVC, vinyl, and seamless aluminum.from asphalt shingle grit granules and be Regardless of material, other necessaryscreened by a fine downspout filter. components in addition to the horizontal gutters are the drop outlet, which routes water-Wood Shingle, Tar, and Gravel from the gutters downward through theThese roofing materials are increasingly rare in downspout pipe. Whenever possible, fit thenew construction, and the water harvested from downspout pipe snugly to the side of the house.this type of surfaces can contain certain If this is not possible then simply make surecontaminants that may limit its use, due to that the pipe is stable and is firmly connectedleaching of some chemical compounds (Texas to the inlet of the tank using rubber grummets.Manual, 2006). Avoid downspouts/pipes installations that could be easily knocked out of position. Sound building and construction practices should prevail. Additional components include the April 2, 2009 DRAFT for Public Comment 31 of 58 Wednesday, April 1, 2009 DRAFT COPY
    • 26 Wednesday, April 1, 2009 DRAFT COPY GEORGIA RAINWATER GUIDELINES MANUAL Georgia Rainwater Harvesting Guidelines concentrates rainfall runoff from two roof planes before the collected rain reaches a A calming inlet is designed to gutter. Depending on the size of roof area mix the relativelly more terminating in a roof valley, the slope of the anaerobic water at the bottom of the tank with the more roof, and the intensity of rainfall, the portion of oxygenated water closer to the gutter located where the valley water leaves the surface of the tank. This is eave of the roof may not be able to capture all installed at the end of the inlet the water at that point. This can result in pipe and rests on the bottom of excessive spillage or overrunning. Therefore the tank. consider installing an overrun dam to minimize water lost at these valley points during heavy rain events (Texas Manual, 2006). Other factors that may result in over running of gutters include an inadequate number of downspouts, excessively long roof distances from ridge to eave, step roof slopes, and inadequate gutter maintenance. Variables such as these make any gutter sizing rule-of-thumb difficult to apply. Consult your gutter supplier/ Figure 4.4 Calming Inlet installer about your situation with special attention to determine where excessive splash-hardware, brackets, and straps to fasten the out may occur (Texas Manual, 2006).gutters and downspout to the fascia and thewall, and finally to the storage tank itself. Gutters should be installed with a slope(Texas Manual, 2006). towards the downspout. Common sense building should prevail whenever modifying or installing a new roof gutter system.-Gutter Sizing and InstallationAlways check with the local building authorityas to compliance with local codes and 4.4 Primary Filtrationordinances. It is important to consider that To remove debris that gathers on the catchmentmany roofs consist of one or more roof surface, and assure high quality water, some“valleys”. A roof valley occurs where two roof filtration is necessary. Some of the many typesplanes meet. This is most common and easy to of filters are shown below.visualize when considering a house with an“L” or “T” configuration. A roof valley April 2, 2009 DRAFT for Public Comment 32 of 58 Wednesday, April 1, 2009 DRAFT COPY
    • Wednesday, April 1, 2009 DRAFT COPY GA RAINWATER GUIDELINES MANUAL 27 Georgia Rainwater Harvesting Guidelines -Downspout Filters The funnel-type downspout filter is typically made of PVC and fitted with an aluminum or stainless steel screen (see Figure 4.5). This type of filter offers the advantage of easy accessibility for cleaning. The funnel is cut into the downspout pipe at the same height or slightly higher than the highest water level in the storage tank. Care must be taken to have the filter high enough to prevent contamination from dogs, but low enough not to discourage the owner/operator from maintaining and cleaning the filter on a regular basis. Figure 4.5 Downspout filter -Strainer Baskets-Leaf Screens Strainer baskets are spherical cage-like strainerThe best first defense in keeping debris out of a that fit into the inlet of the tank. Therainwater harvesting system is a leaf screen homeowner may need to experiment withalong the gutter or in the downspout. It helps various strainer basket screen sizes. Availableprevent large debris form entering the storage screen sizes range from fine filters to coarsetank. These screens are usually made of 1/4 mesh sizes. See Figure 4.6.inch mesh in wire frames that fit along thelength of the gutter. Leaf screens must beregularly cleaned to be effective. If notregularly maintained, leaf screens can becomeclogged and prevent rainwater from theflowing into the tank. Built-up debris can alsoharbor bacteria and compromise the quality ofwater.Leaf guards/screens are necessary in locationswhere trees are nearby or overhanging (mpstlocations in the Southeastern U.S.). Guardswith profiles conducive to allowing leaf litterto slide off are also available. Figure 4.6 Strainer Basket April 2, 2009 DRAFT for Public Comment 33 of 58 Wednesday, April 1, 2009 DRAFT COPY
    • 28 Wednesday, April 1, 2009 DRAFT COPY GEORGIA RAINWATER GUIDELINES MANUAL Georgia Rainwater Harvesting Guidelines-First-Flush DivertersCommon sense tells us that a roof can be a An exact one size fit-all formula fornatural collection surface for dust, leaves, calculating how much initial waterblooms, twigs, insect bodies, droppings, needs to be diverted from the tankpesticides, and other airborne residues. The as first flush does not existfirst-flush diverter routes the first flow of water because there are so manyfrom the catchment surface away from the variables. For example, the slopestorage tank. The flushed water can be routed and smoothness of the collectionto a planted area. While leaf screens remove surface, the intensity of the rainthe larger debris, such as leaves, twigs, and event, the length of time betweenblooms that fall on the roof, the first-flush events (which adds to the amountdiverter gives the system a chance to rid itself of acculmulated contaminants),of the smaller contaminants, such as dust, and the nature of thepollen, and bird and rodent droppings. contaminants. In order to effectively wash a collectionThe simplest first-flush diverter is constructed surface and thus reduce thewith a PVC standpipe. The standpipe fills with amount of contaminants enteringwater first during a rainfall event; the balance the collection storage, one mustof water is routed to the tank. The standpipe is take into account the factorsdrained continuously via a pinhole or bay previously mentioned.leaving the screw closure slightly open. In anycase, cleaning of the standpipe is accomplishedby removing the PVC cover and removingcollected debris after each rainfall event (TexasManual, 2006). There are several other types offirst-flush diverters. The ball valve typeconsists of a floating ball that seals off the topof the diverter pipe (Figure 4.7) when the pipefills with water. Opinions vary on the volumeof rainwater to divert to the first flush device.The number of dry days, amount and type ofdebris, and roof surface are all variables toconsider. Figure 4.7 First Flush Diverter April 2, 2009 DRAFT for Public Comment 34 of 58 Wednesday, April 1, 2009 DRAFT COPY
    • Wednesday, April 1, 2009 DRAFT COPY GA RAINWATER GUIDELINES MANUAL 29 Georgia Rainwater Harvesting Guidelines4.5 Storage Ferrocement owner-built tanks are another option and can provide significant storage atThe storage tank or cistern generally is the relatively low costs. Table 4.1 describes somemost important design of a component of a of these options and provides a featurerainwater harvesting system. In most cases it is comparison.permanent and its placement should becarefully thought out. For purposes of practicality, this manual will focus on the most common, easily installed,The size of the storage is dictated by several and readily available storage options invariables including: the rainwater supply (local Georgia. Storage tanks for indoor non-potableprecipitation), demand, projected length of use must be made of nonabsorbent andtime without rain (dry spells), catchment corrosion-resistant materials. Tanks must besurface area (larger area equals more water), opaque, either upon purchase or painted later toaesthetics, personal preference, and budget. A inhibit algal growth. Smallmyriad of variations on amounts of light, especiallystorage tanks and cisterns sunlight, can stimulate algal Water weighs just over 8have been used over the growth and can cause a thick pounds per gallon, socenturies, some of which soup-like formation in the even a relatively smallare: earthenware cisterns in tank. In addition, rainwater 1,500 gallon tank willancient times, large pottery harvesting system storage weigh 12,400 pounds.containers in Africa, above- tanks must never have beenground vinyl-lined used to store toxic materials.swimming pools in Hawaii, Tanks must be covered andconcrete or brick cisterns in the central United provided with vents screened to discouragedStates, and galvanized steel tanks and attractive mosquito breeding. They must be accessiblesite-built stone-and-mortar cisterns (Texas for cleaning and maintenance.Manual, 2006). -Tank SitingAn above-ground storage tank need not to be Cisterns may be installed above or belowan eyesore. Plastic or metal tanks can be grade. In some project application tanks maywrapped with wood and fitted with metal tops be partially buried or rainwater may beresulting in aesthetically pleasing additions to collected in a small tank below ground andthe landscape. They can be screened with plant then pumped into an above ground storagematerial or fencing. Corrugated metal tanks can tank. Research local ordinances, covenants,reflect architectural elements in some and restrictions, when selecting storage tankcommercial and residential applications. types. Determine if the tank will need to be April 2, 2009 DRAFT for Public Comment 35 of 58 Wednesday, April 1, 2009 DRAFT COPY
    • 30 Wednesday, April 1, 2009 DRAFT COPY GEORGIA RAINWATER GUIDELINES MANUAL Georgia Rainwater Harvesting Guidelines Figure 4.8 Wooden tankburied or camouflaged. Consider how your The following are additional considerationsRWH system will be viewed by neighbors, and when selecting an ideal tank location. Locatetry to minimize any negative aesthetic impacts. tanks as close to the supply and demand points as possible to reduce the distance water isUnderground utilities, high water tables or conveyed. To ease the load on the pump, tanksshallow bedrock may limit the sites available should be placed as high as practicable. Offor tank burial. Locate utilities, and investigate course, the tank inlet must be lower than thegroundwater and geological restrictions during lowest downspout from the catchment area.the planning phase. Buoyant forces can act on When converting from the well water, or ifan empty underground and cause it to float out using a well backup, siting the tanks near theof ground. Careful consideration should be well house facilitates the use of existinggiven to manufacturer’s installation guides and plumbing. Overflow from tanks must beinstructions in order to correctly site and diverted to normal stormwater pathways in aprotect tanks against negative impacts of soils non erosive manner. In addition, water runoffwith a high water table. from tank overflow should not enter septic system drain fields, and tank overflow and April 2, 2009 DRAFT for Public Comment 36 of 58 Wednesday, April 1, 2009 DRAFT COPY
    • Wednesday, April 1, 2009 DRAFT COPY GA RAINWATER GUIDELINES MANUAL 31 Georgia Rainwater Harvesting Guidelines MATERIALS FEATURES CAUTION Plastics Barrels 55 gal-150 gal Commercially available; Use only new cans Inexpensive Fiberglass Commercially available; Must be sited with smooth, solid Alterable and moveable level footing Polyethylene/polypropylene Commercially available; May be UV-degradable, can be Alterable and moveable painted or tinted if not inhibited Metals Steel Drums (55-gallons) Commercially available; Verify prior to use for toxics; Alterable and moveable Prone to corrosion and rust. Galvanized steel tanks Commercially available; Possible corrosion and rust; Alterable and moveable Should be lined for indoor use Concrete and Masonry Ferrocement Durable and immoveable Potential to crack and fail Stone, concrete block Durable and immoveable Difficult to maintain Monolithic/Poured-in-place Durable and immoveable Dotential to crack and fail Wood Redwood, fir, cypress Attractive, durable, can be Expensive disassembled and moved Table 4.1 Storage tank materials descriptionsApril 2, 2009 DRAFT for Public Comment 37 of 58 Wednesday, April 1, 2009 DRAFT COPY
    • 32 Wednesday, April 1, 2009 DRAFT COPY GEORGIA RAINWATER GUIDELINES MANUAL Georgia Rainwater Harvesting GuidelinesHeight 6-foot 12-foot 18-foot drainage should be routed so that it does not affect the foundation of the tanks or any other(feet) Diameter Diameter Diameter 6 1.269 5.079 11.421 structures (Macomber, 2001). To ensure a safe water supply, underground tanks should be 8 1.692 6.768 15.227 located at least 50 feet away from animal 10 2.115 8.46 19.034 stables or above ground application of treated 12 2.538 10.152 22.841 wastewater. Tank placement should also take 14 2.961 11.844 26.648 into consideration accessibility by a delivery 16 3.384 13.535 30.455 truck for installation or removal, preferably 18 3.807 15.227 34.262 near a driveway or roadway. 20 4.23 16.919 38.069 Existing structures should be considered when Table 4.2 Tank volume for a given height installing a RWH system. Water is normally and diameter (1,000 GAl units) conveyed from downspouts to storage tanks by gravity. Think carefully about the location of Figure 4.9 Schematic for 350 gallon Rain barrel April 2, 2009 DRAFT for Public Comment 38 of 58 Wednesday, April 1, 2009 DRAFT COPY
    • Wednesday, April 1, 2009 DRAFT COPY GA RAINWATER GUIDELINES MANUAL 33 Georgia Rainwater Harvesting Guidelinesgutters and downspouts to maximize the use ofexisting gutters and to collect water from a roofarea that will support water demand. The tankfoundation must be flat, and capable ofsupporting the weight of maximum storage. Aleaning tank may collapse; therefore, tanksshould be placed on a stable, level pad. Whenthe condition of the soil is unknown, enlistingthe services of a structural engineer may benecessary to insure the stability of the soil Figure 4.11 Plastic polypropylene tankssupporting the full cistern weight. The pad orbed should be inspected after rainfall events. -Rain Barrel One of the simplest rainwater installations, andLocate tanks in areas that are not subject to a practical choice for many urban dwellers, iserosion, flooding or other factors that might the 55 to 75-gallon drum used as a rain barrelundermine the integrity of the foundation. for watering of plant beds. Some commerciallyConsider how electricity can be delivered to available rain barrels are manufactured withthe pump of your RWH system, and how upper and lower ports linking the primaryrainwater supply lines can be safely added t barrel to a second barrel (and potentiallyexisting plumbing. others) linked together in series. Screening at any orifice or entry point to the tank4.6 Tank Materials discourages vectors such as mosquitos. A food- grade plastic barrel used for bulk liquid storage in restaurants and grocery stores can be fitted with a bulkhead fitting and spigot for garden watering. However those that are not opaque must be screened from sunlight. -Above Ground Polypropylene Polypropylene tanks are commonly sold at farm and ranch supply retailers for all manner of storage uses. They are also a available through internet companies. Standard tanks must be installed above ground. For below Figure 4.10 75 gallon Rain barrel ground installations, specially reinforced tanks April 2, 2009 DRAFT for Public Comment 39 of 58 Wednesday, April 1, 2009 DRAFT COPY
    • 34 Wednesday, April 1, 2009 DRAFT COPY GEORGIA RAINWATER GUIDELINES MANUAL Georgia Rainwater Harvesting Guidelines Figure 4.12 Below ground Fiberglass tanksare necessary to withstand soil pressures petroleum and water storage industries. Theyexpansion and contraction. They are relatively are easily repaired. The fittings on fiberglassinexpensive, durable, lightweight, and long tanks are an integral part of the tank,lasting. Polypropylene tanks are available in eliminating the potential problem of leakingcapacities from 300 gallons up to 10,000 after an after-market fitting that may be fieldgallons. Polypropylene tanks do not retain installed improperly (Texas Manual, 2006).paint well, so it is necessary to find off-the- The tanks in Figure 4.11 would have to beshelf tanks manufactured with opaque plastic. placed on a suitable foundation and then beThe fittings of these tanks generally com with backfilled with the appropriate backfillthe tank itself (Texas Manual,2006). material. -Below Ground Polypropylene-Fiberglass Tanks are buried typically for aesthetic orFiberglass tanks are built in standard capacities space-saving reasons. In-ground tanks are oftenup to 50,000 gallons and in both vertical and more costly than their above groundhorizontal configurations. The durability of counterparts for two reasons: the cost offiberglass has been tested and proven, excavations and structural requirements of theweathering the elements for years in the tank itself. The cost of a more heavily April 2, 2009 DRAFT for Public Comment 40 of 58 Wednesday, April 1, 2009 DRAFT COPY
    • Wednesday, April 1, 2009 DRAFT COPY GA RAINWATER GUIDELINES MANUAL 35 Georgia Rainwater Harvesting Guidelinesreinforced tank needed for installation at thicker and with interior bracing structures.depths of two feet or more can drive up the Certain tanks in certain soils and location typestank prices. These deeper installations require may not be suitable for direst burial (Texasthe walls of poly tanks t be manufactured Manual, 2006). Figure 4.13 Below ground polypropylene tanks Caution: Never install a tank without referring to the manufacturer’s installation instructions. Underground tanks are for underground applications only. In many parts of Georgia expansive soils are common (clay) and they can collapse underground tanks if installed incorrectly. Make sure to confirm that the selected underground tank is compatible with its surrounding soils, and that the foundation and backfill are in accordance with the manufacturer’s recommendations. April 2, 2009 DRAFT for Public Comment 41 of 58 Wednesday, April 1, 2009 DRAFT COPY
    • 36 Wednesday, April 1, 2009 DRAFT COPY GEORGIA RAINWATER GUIDELINES MANUAL Georgia Rainwater Harvesting GuidelinesSome owners of RWH systems use multiplesmaller tanks in sequence to meet their storageneeds. This has the advantage of allowing theowner to empty a tank to perform maintenanceon one tank at a time without losing all waterin storage. However this approach can increasethe cost to redundancy in materials andinstallation procedures.-MetalGalvanized sheet metal tanks (Figure 4.13) arealso an attractive option for the urban orsuburban garden. They are available in sizesfrom 1,500 to over 200,000 gallons, and arelightweight and easy to relocate. Most tanksare corrugated galvanized steel dipped in hotzinc for corrosion resistance. When line, theyare lined with polyethylene or PVC, or coatedon the inside with epoxy paint. The paint,which also extends the life of the metal, should Figure 4-14 Corrugated steel tankbe Federal and Drug Administration (FDA) andNational Sanitation Foundation (NSF) patio or a basement, and their placement isapproved. Bolted steel tanks can be transported considered permanent. Involving the expertiseand assembled virtually anywhere with a small of a structural engineer to determine the sizecrew and are not hindered by transportation and spacing of reinforcing steel to match thesizes as other tanks may be. These systems are structural loads of a poured-in-place concretesold in kit form and can be bolted together with citern is highly recommended (Texas Manual,a few tools. Some tank manufacturers of this 2006). A concrete tank constructed oftype require certified installers for full prefabricated stacked rings with sealant aroundwarranties. the joints is another possibility. A more common type in Georgia is the use of new,-Concrete previously unused underground septic tanks.Concrete tanks are either poured in place or These tanks are fabricated off-site and droppedprefabricated. They can be constructed above into place.ground or below ground. Poured-in-place tankscan be integrated into new construction under a April 2, 2009 DRAFT for Public Comment 42 of 58 Wednesday, April 1, 2009 DRAFT COPY
    • Wednesday, April 1, 2009 DRAFT COPY GA RAINWATER GUIDELINES MANUAL 37 Georgia Rainwater Harvesting Guidelines -Wood For aesthetic appeal, a wooden tank is often a highly desirable choice for urban area and suburban rainwater storage. Wooden tanks, similar to wooden water towers at railroad depots, were historically made of redwood. Modern wooden tanks are usually made of pine, cedar, or cypress wrapped with steel tension cables, and line with a heavy mil plastic or vinyl liner. These tanks are available in capacities from 700 to 200,000 gallons, and are site-built by skilled technicians. They can also be dismantled and reassembled at a different location (Texas Manual, 2006). Figure 4.15 Wooden aboveground tankConcrete may be prone to cracking and 4.7 Pumps and Controlsleaking, especially when underground tanks are Since elevation separation (distance in verticallocated in clay soil. Leaks can be easily height from water storage to end use) is rarelyrepaired although the tank may need to be sufficient to give even the minimal pressuredrained to make the repair. To prevent leakage needed, two common ways to achieve properconcrete tanks should be line or sealed. household water pressure are (a) a pump, pressure tank, pressure switch, and check valve (familiar to well owners), or (b) an on-demand- Use Pressure Pressure Flow (ft) (psi) Impact Sprinkler 93 40 4.5 GPM Pressure washer 46 20 4 gpm Toilet 46 20 6 gpm Garden hose 81 35 5 gpm nozzle Table 4.3 Typical minimum requirements of commons fixtures in water-harvesting April 2, 2009 DRAFT for Public Comment 43 of 58 Wednesday, April 1, 2009 DRAFT COPY
    • 38 Wednesday, April 1, 2009 DRAFT COPY GEORGIA RAINWATER GUIDELINES MANUAL Georgia Rainwater Harvesting Guidelinespump. Pumps systems draw water from thestorage tanks, pressurize it,and store it inpiping networks. Sometimes a bladder typepressure tank is needed to maintain certainpressures. Pressure tanks prevent the pumpfrom cycling on and off to meet smalldemands. The typical pump and pressure tankarrangements consists of a 3/4 or 1horsepower pump, usually a shallow well jetpump or a multistage centrifugal pump, thecheck valve, and pressure switch. A one-waycheck valve between the storage tank and the Figure 4.17 On demand external pumppump prevents pressurized water from beingreturned to the atmospheric pressure tank. The system. When the pressure tank reaches apressure switch regulates operation of the preset threshold, the pressure switch cuts offpump thereby controlling pressure in the tank. power to the pump. When there is demandThe pressure tank, with a typical capacity of 40 from the household, the pressure switch detectsgallons, maintains pressure throughout the the drop in pressure in the tank and activates the pump, drawing more water into the pressure tank. On-demand pumps eliminate the need for a pressure tank. They are designed to activate in response to a demand. These pumps combine a pump, motor, controller, check valve, and pressure switch with pressure tank function all in one unit. They are self-priming and are built with a check valve incorporated into the suction port. In addition, some on-demand pumps are specifically designed to be used in rainwater systems. Intake filters are designed to exclude debris from the pump intake. These filters assist in preventing cloggs, improving reliability, and Figure 4.16 Submersible on demand increasing pump life. The floating suction filter pump with floating suction (see Figure 4.15) attached to the intake on the April 2, 2009 DRAFT for Public Comment 44 of 58 Wednesday, April 1, 2009 DRAFT COPY
    • Wednesday, April 1, 2009 DRAFT COPY GA RAINWATER GUIDELINES MANUAL 39 Georgia Rainwater Harvesting Guidelinespump allows the pump to draw water from thestorage tank 6 to 16 inches below the watersurface. Water at this level is cleaner, fresherand relatively more oxygenated than watercloser to the bottom of the tank. These deviceshave some filtration, usually between 100 and200 microns.Choose a pump that is capable of delivering theflow and pressure needed to meet the particulardemands of the system. Consult a plumbingcontractor to determine the pressurerequirements for any indoor toilet or urinalflushing.4.8 Treatment andDisinfectionRWH systems less than 200 gallons for outdoornon-potable applications normally need notreatment or disinfection. Larger outdoorsystems may require treatment and disinfectionappropriate for the end use of the water, and allindoor systems used for toilet flushing or urinalflushing require treatment and disinfection.This subject is covered in detail in Chapter 5. April 2, 2009 DRAFT for Public Comment 45 of 58 Wednesday, April 1, 2009 DRAFT COPY
    • 40 Wednesday, April 1, 2009 DRAFT COPY GEORGIA RAINWATER GUIDELINES MANUAL Georgia Rainwater Harvesting GuidelinesCHAPTER 5WATER QUALITY ANDTREATMENTCOMPONENTS5.1 Introduction 5.2 Factors Affecting theThe raindrop as it falls from the cloud is Quality of Harvestednormally free of harmful pathogens and Rainwaterchemicals. The environment, the catchmentsurface, and the storage tanks can affect the Although rainwater is relatively pure, it is stillquality of harvested rainwater (Texas Manual, necessary to establish minimum water quality2006). Unnecessary degradation of roof- guidelines for its use. Roof collected rainwatercollected rainwater can be minimized by will come in contact with certain contaminantssensible preventive management procedures. as it moves from the roof to the storage tank.Some of these measures are associated with Where rainwater is used for outdoordesign and installation, while others are operations, such as irrigation or outdoor hoseassociated with ongoing maintenance. Well bibbs, etc., minimal, if any, filtration isdesigned systems will generally prevent required. Collecting rainwater for indoorproblems from occurring, so corrective action purposes does require a number of steps toto restore water quality will be needed insure its successful use.infrequently. Roof-collected rainwater that iscaptured and stored correctly can be a safe, Tree branches and any vegetation thateconomical and sustainable source of water interferes with the gutters should be pruned.(Abbott, 2008). Gutters may be screened or fitted with leaf- guards to prevent larger objects from washingIt is important to note that the owner of a down from the roof. Downspouts can haverainwater harvesting system becomes the filters placed in line with the water flow toowner of “their own” water supply system. further remove large particulates.This represents a dramatic departure from justturning on the tap and expecting the water to “First flush diverters (See Figure 5.1) areflow out. The owner is solely responsible for devices that minimize contamination of theroutine operation, including maintaining clean rain tank water by diverting the first amount ofgutters and filters, repairing leaks, monitoringof water quality and performing system rain which washes away the dust, debris, birdupgrades. April 2, 2009 DRAFT for Public Comment 46 of 58 Wednesday, April 1, 2009 DRAFT COPY
    • Wednesday, April 1, 2009 DRAFT COPY GA RAINWATER GUIDELINES MANUAL 41 Georgia Rainwater Harvesting Guidelines plumbing fixtures. Further discussion of filtration is included in the components chapter. Once again, the end use of the water will determine the type and level of filtration. • Collection Surface Contamination During the conveyance process from catchment surface to storage tanks, water can become contaminated with bird wastes, air borne pollutants, mosquitoes, small animals and other organic and inorganic materials, including the roof material itself. In the Southeastern US, springtime pollen can fall in seemingly unending quantities. This Figure 5.1 First flush diverter pollen can build up and is not desirable inside the tank. In addition to first flush diverters,and other animal droppings, etc., off the roof tank overflow located near the top of the tankaway from the tank” (Abbott, 2008). helps direct some of these contaminants awayAs a general rule of thumb, the cleaner the from the tank.water going into the cistern, the higher thewater quality and the better the system’s • Algae Growth and Vectorsoverall performance will be. According to Stan Tanks that are not opaque permit light to enterAbbott “spectacular improvements in the water and stimulate the growth of algae. Relativelywater quality in the rain tanks are attributed to little amounts of light, even indirect light, arefirst flush diverters” (Abbott, 2008). needed to grow algae in a closed tank. Opaque tanks are better at maintaining higher waterWhere rainwater is used for non-potable use quality. Proper screening of inlets, outlets, andinside an occupied facility, i.e. toilets, urinals, overflows connected to the tank will furtherand cooling tower make-up, the water must be reduce the effects of vectors such asappropriately disinfected as required by State mosquitoes.code. In addition, the water must also be • Sediment Buildupfiltered as a safeguard against small debris or It is impractical to completely eliminatesediment entering the toilet valves, thus sediment from entering and accumulating inmaintaining proper function. This filtration will the tank. Sediment found in rain tanks isalso assist in the prevention of discoloration of normally composed of both inorganic and April 2, 2009 DRAFT for Public Comment 47 of 58 Wednesday, April 1, 2009 DRAFT COPY
    • 42 Wednesday, April 1, 2009 DRAFT COPY GEORGIA RAINWATER GUIDELINES MANUAL Georgia Rainwater Harvesting Guidelinesorganic materials. Proper inlet water screening system. Harvested rainwater intended forand the addition of a first flush diverter will aid indoor uses must be filtered and disinfected, inin minimizing sediment buildup in storage accordance with all relevant state plumbingtanks. It takes very small amounts of organic codes.matter material to adversely affect the odor andcolor of the stored water. • Filtration Cartridge filters may be placed on the5.3 Water Treatment For discharge side of the pump, which providesNon-potable Outdoor Use pressure to the plumbing system. To ensure adequate flow and pressure of the water supply,Systems the filters need to be sized for the intended useWhere rainwater is used for non-potable use of the water. A number of different filters cansuch as hand-watering, vehicle washing, etc., be used to provide the particulate removaland for non-critical operations, such as necessary to address the specific non-potableirrigation and wash down, a high level of water use. Filters of different sizes and fromfiltration may not be necessary. However, some numerous manufacturers are commerciallyfiltration will likely be needed to prevent available.clogging sprinklers, or drip irrigation emitters.Filtration sufficient for the successful working The presence of suspended material in water,of the equipment is generally all that is such as finely divided organic material, such asrequired for outdoor non-potable systems. plankton, and clay, silt and other inorganic material is indicated through turbidity,Drip irrigation manufacturers or vendors (cloudiness) measured as NTU (nephelometricshould be contacted regarding filtering of water turbidity units). High turbidity interferes withfor these types of irrigation systems. disinfection. Maintaining turbidity levels below 10 NTU improves disinfection effectiveness (AWWA, 2006). According to the Texas5.4 Water Treatment For Rainwater Harvesting Evaluation Committee, aNon-potable Indoor Use 5 micron sediment filter is adequate forSystems reducing the suspended solids for non potable indoor uses. A higher level of treatment can be• Use in Toilet and Urinal Flushing achieved with a 3 micron sediment filterFor non-potable water systems, where followed by a 3 micron activated carbon filter.rainwater is used indoors, treatment generally In order to assure that the filter does not leachconsists of filtration and disinfection processes undesirable contaminants into the water, usein series before distribution to the plumbing April 2, 2009 DRAFT for Public Comment 48 of 58 Wednesday, April 1, 2009 DRAFT COPY
    • Wednesday, April 1, 2009 DRAFT COPY GA RAINWATER GUIDELINES MANUAL 43 Georgia Rainwater Harvesting Guidelinesfiltration systems that have been certified to passing the water through ultraviolet light, ormeet ANSI/NSF Standard 61 requirements. treating it with chlorine.• Disinfection Even though bacterial contamination of waterDisinfecting rainwater for indoor non-potable for indoor non-potable use is not as critical asuse is required to control microbial growth that that used for potable purposes, total coliformcould cause odors and affect the operation of and fecal coliform sampling can be used toplumbing fixtures. evaluate a general level ofDisinfection can be acceptable microbialaccomplished in a The Georgia plumbing code contamination for non- p o t a b l e w a t e r. T h enumber of ways 2009 (Georgia Amendments toincluding ultraviolet acceptable level of total the 2006 International(U.V.) disinfection, coliform for non-potable Plumbing, Appendix I, water should be less thanozonization, reverseosmosis and “Rainwater Recycling 500 cfu/100 ml, and fecal coliform levels should bechlorination. Systems”) allows rainwater to less than 100 cfu/100 ml. be collected, treated and used (Lye, 2005). Keep in mindTesting conducted in indoors for toilet and urinal that the more the system isGermany demonstratesthat the risk of E.coli flushing, and as cooling tower monitored for water quality, the better the system willcontact with the human makeup water. This representsmouth from toilet perform. Table 5.1 details a major step forward in some treatment techniquesflushing was virtuallynon-existent (Ecker, pursuing water conservation commonly used in RWH.2007). This study goals in the state of Georgia.resulted in a •Chlorinationrecommendation that For those choosing tospecial disinfection measures were unnecessary disinfect with chlorine, automatic self-dosingfor rainwater dedicated to non-potable uses. systems are available. Following filtration, anHowever, according to the Texas Rainwater in-line erosion chlorinator, or an injectionHarvesting Evaluation Committee (2006), pump can be used to disinfect harvesteddisinfecting non-potable rainwater for indoor rainwater, and maintain a level of 0.2 mg/L ofuse is desirable to control microbial growth chlorine residual. In-line erosion chlorinatorswhich could cause fowling and affect the are one option for chlorinating harvestedoperation of plumbing fixtures. Following rainwater. Calcium hypochlorite tablets orfiltration, disinfection can be accomplished by pellets are placed inside the erosion April 2, 2009 DRAFT for Public Comment 49 of 58 Wednesday, April 1, 2009 DRAFT COPY
    • 44 Wednesday, April 1, 2009 DRAFT COPY GEORGIA RAINWATER GUIDELINES MANUAL Georgia Rainwater Harvesting Guidelineschlorinator; as water flows through the unit, the charcoal can absorb objectionable odors andcalcium hypochlorite slowly dissolves and tastes, and even some protozoa and cystsreleases chlorine into the water. (Macomber, 2001).Use chlorine compounds that are certified in In order for a UV system to work properly, theaccordance with ANSI/NSF Standard 60 water passing through it must be relativelyrequirements. Avoid products that contain clear and free of particles. UV disinfectionfragrances and UV stabilizers. Do not use must be proceeded by adequate filtration. Theproducts designed for use in ANSI/NSF standard 55swimming pools as these establishes testingproducts often contain It is important to note that requirements for UVcyanide based UV stabilizers. the water must be passed water treatment systems. UV systems that meet through a sediment/• Cartridge Filters and Class A requirements of particulate filter and this standard are capable Ultraviolet (UV) Light possibly carbon filter (for of producing an UV dose of 40 mJ/cm2. The UVWhen using UV light it is odor control) prior toimportant to follow the light must be rated to entering the U.V.manufacturer’s installation accommodate the flow. It chamber. is best to purchaseguidelines and to pre-filter thewater before it enters the UV certified equipment.chamber. Maintenance of the UV light involves cleaning of the quartz sleeve andOne possible disinfection array consists of two the bulb itself. Some UV lights are designedinline filters in series, (a particulate fiber with an integral wiper unit. Again, follow thecartridge filter followed by an activated m a n u f a c t u r e r ’s i n s t r u c t i o n s a n dcharcoal filter), and an ultraviolet light. This recommendations.disinfection set-up is placed after the on-demand pump. It is important to note that • Ozonecartridge filters must be replaced regularly. Chemically, ozone is O3. It is essentially aOtherwise, the filters can actually harbor more reactive form of molecular oxygen madebacteria and their food supply. Clear-bodied up of three atoms of oxygen. Ozone acts as aholders are slightly more costly but allow the powerful oxidizing agent to reduce color,user to visually check the filter from the eliminate foul odors, and reduce total organicoutside. The filter mechanically removes carbon in water. For disinfection purposes, ansuspended particles. In theory, activated ozone generator forces ozone into storage tanks April 2, 2009 DRAFT for Public Comment 50 of 58 Wednesday, April 1, 2009 DRAFT COPY
    • Wednesday, April 1, 2009 DRAFT COPY GA RAINWATER GUIDELINES MANUAL 45 Georgia Rainwater Harvesting Guidelines Method Location ResultSCREENINGLeaf Screens and Strainers Gutters and downspouts Prevents leaves and other debris from entering the tankSETTLINGSedimentation Within tank Settles out particulate matterActivated Charcoal Before tap Removes chlorineFILTERINGRoof washer Before tank Eliminates suspended materialIn-line/multi-cartridge After pump Sieves sedimentActivated charcoal After sediment filter Removes chlorine, reduces odorFirst flush Diverter Before tank Reduces suspended materialSand Filtration After pump Removes particulatesMICROBIOLOGICAL TREATMENT/DISINFECTIONBoiling/distilling Before use Kills microorganismsChemical treatments Within tank or at pump Kills microorganisms(Chlorine ) (liquid, tablet, or granular) Before activated charcoal filterUltraviolet Light After activated charcoal filter Kills microorganisms Before tapOzonization After activated charcoal filter Kills microorganisms Before tap Table 5.1 Treatment Techniques April 2, 2009 DRAFT for Public Comment 51 of 58 Wednesday, April 1, 2009 DRAFT COPY
    • 46 Wednesday, April 1, 2009 DRAFT COPY GEORGIA RAINWATER GUIDELINES MANUAL Georgia Rainwater Harvesting Guidelinesthrough rings or a diffuser stone. Ozone is inside plumbing system provides makeup waterunstable and reacts quickly to revert to O2 and to these systems, always incorporating backdissipates through the atmosphere within 15 flow prevention. Therefore it is important thatminutes. Although ozone is a powerful water-cooled equipment used to conditiondisinfectant, careful consideration should be interior spaces or equipment located inside ofg i v e n t o f o l l o w i n g m a n u f a c t u r e r ’s structures meet the requirements of the indoorrecommended installation guidelines (Texas plumbing codes and guidelines.Manual, 2006). 5.6 Conclusions• Corrosion Control Rainwater is not subject to the same level ofRainwater that is slightly acidic, contains a few contamination as surface water supplies,dissolved minerals that can be corrosive. especially when proper care is taken during theBecause harvested rainwater that is used rain harvesting process. Appropriate filtration/indoors in Georgia will only be delivered to treatment does not mean one size fits all. Thetoilets and urinals, the use of plastic delivery end use determines the level of filtrationpipe, and fixtures made with non-corrosive needed. Common sense and sound installationmaterials are recommended. practices should prevail. Careful ongoing and recurring maintenance by the owner or operator is the best way to assure the highest5.5 Additional level of water quality. Numerous otherRequirements for Use as resources are available from the state of TexasCooling Tower Make Up that address this subject in greater detail,( see references section).WaterCooling towers, evaporative condensers andfluid coolers are required to be installed inaccordance with the manufacturers installationinstructions, with additional specificrequirements listed under section 908 of theInternational Mechanical Code (IMC).Although almost all cooling towers andevaporative cooled mechanical equipment arelocated outside since they normally utilizeoutdoor air as well to operate, normally the April 2, 2009 DRAFT for Public Comment 52 of 58 Wednesday, April 1, 2009 DRAFT COPY
    • Wednesday, April 1, 2009 DRAFT COPY GA RAINWATER GUIDELINES MANUAL 47 Georgia Rainwater Harvesting GuidelinesGLOSSARYCALMING INLET. A device located at the of total suspended solids (TSS); while otherbottom of a storage tank that permits water to forms of filtration, such as carbon / absorptionenter a storage tank with minimal disturbance filtration, removes dissolved compoundsto particles that may have settled to the bottom measured in units of total dissolved solidsof the tank. ( TDS ).CISTERN. The central water storage FIRST FLUSH DEVICE. A device orcomponent of the rainwater harvesting system. method for removal and debris from collectionProtection and maintenance of the cistern or surface by diverting initial rainfall from entrystorage tank is essential for the health of the into the cistern.system. FLAT. Having a slope no greater than 1 in 50.CODE. Refers to the International PlumbingCode with Georgia Amendments as well as GROUND WATER. Water that infiltrates intoother Georgia State Minimum Standard Codes the ground and no longer flows across theand local ordinances. surface.COLLECTION AREA. Area from whichrainwater is collected for use in a rainwater HARVESTED WATER. Rainwater that isharvesting system (e.g. roof area). collected in the cistern.DEBRIS EXCLUDER. A screen or other HYDRAULIC FILTERdevice installed on the gutter or down spout EFFICIENCY. Ratio between the watersystem to prevent the accumulation of leaves, amount flowing to the filter and the waterneedles, or other debris in the system. amount supplied for utilization.DISINFECTION. Reduction of viable micro- INFILTRATION FIELD. Element in theorganisms to a level that is deemed suitable for ground that is filled with gravel, ballast orthe intended applications. Typical units of special non-permeable plastic elements andmeasure are Colony Forming Units per deca- that stores rainwater that is fed into it on anliter (cfu / dl). intermediate basis before the water evaporates into the atmosphere or seeps into theDRY RUNNING PROTECTION. System surrounding soil.for protecting the water pump against runningwhen no water is present. LEACH FIELD, EVAPORATION /FILTRATION. Physical removal of liquid- TRANSPIRATION FIELD. Element in theborn contaminants by means of separation ground that is filled with gravel, ballast orfrom the output flow. Particulate filtration special permeable plastic elements and thatremoves suspended particles, measured in units stores rainwater that is fed into it on an April 2, 2009 DRAFT for Public Comment 53 of 58 Wednesday, April 1, 2009 DRAFT COPY
    • 48 Wednesday, April 1, 2009 DRAFT COPY GEORGIA RAINWATER GUIDELINES MANUAL Georgia Rainwater Harvesting Guidelinesintermediate basis before the water seeps into that is expected to be reunited in a specifiedthe surrounding soil. period of time.MAKE-UP WATER SUPPLY. Municipal SYSTEM PRESSURE. Pressure needed towater or other reliable water source that is used deliver water to the designated fixtures.to supply the cistern when the harvested wateris depleted. To be used for essential needs such QUANTITY OF PRECIPITATION. Amountas flushing a toilet. of rain, expressed as the water height in inches over a horizontal area for a span of time underMINIMUM WATER VOLUME. Residual consideration.water volume that is constrained by the processin which neither sediment nor scum can be RAINWATER. Water collected from runoffsucked in for the protection of the pump. of roofs or other structures after a rain event. Rainwater may also include condensate.OVERFLOW LEVEL. The highest level thatwater in a cistern can rise before flowing out of RAINWATER HARVESTING SYSTEM.the tank. Water system for utilizing rainwater, consisting of a cistern ,pipe, fittings, pumps and/or otherOVERFLOW LINE. Line for leading excess plumbing appurtenances, required for and/orrainwater away when the cistern is full. used to harvest and distribute rainwaterPIPING SYSTEM. Pipes that convey the RAINWATER YIELD. Useful water volumeharvested rainwater and distribute it to various (water inflow) determined over a certain periodfixtures. of time.PRECIPITATION CHARACTERISTICS. RETURN ELBOW. A section of pipe with aCharacteristics of a precipitation event (e.g. 180-degree bend.intensity, duration). ROOF DRAINAGE SYSTEM. A system,PROCESS WATER. Water for household and comprised of roof drains, overflow drains,commercial areas of use that does not have to scuppers, gutters and down spouts, used tohave the quality of drinking water. convey the rainwater from the roof surface to the cisternPROCESS WATER LINE. System of linesfrom the process water pump to the individual ROOF FILTRATION. A device or procedurepoints at which water is drawn. to mechanically remove sediment and debris (i.e. first flush diverters).PROCESS WATER PUMP. Pumps processwater from the rainwater reservoir to the points SCREEN. A filtration device, constructed ofat which water is drawn. corrosion resistant wire or other approved mesh, having openings in determined areas.PROCESS WATER REQUIREMENTS.Planning value for the process water amount April 2, 2009 DRAFT for Public Comment 54 of 58 Wednesday, April 1, 2009 DRAFT COPY
    • Wednesday, April 1, 2009 DRAFT COPY GA RAINWATER GUIDELINES MANUAL 49 Georgia Rainwater Harvesting GuidelinesSEDIMENTATION. Separation of solidsfrom the water via gravity.SLOPED OR SLOPING. Having a slopegreater than 1 in 50.SUB-SURFACE IRRIGATION. Water thatis applied below ground level and is notdirectly exposed to the above ground surfaceand/or surrounding air.SUN BARRIERS. A cover, or erectedstructure, specifically to shelter a cistern fromthe direct rays of the sun.SURFACE IRRIGATION. Water that isapplied above ground level and is directlyexposed to the above ground surface and/or air.SURFACE WATER. Any rainwater thattouches the ground and flows across thesurface of the ground (roadway, parkingsurface, gully, creeks, streams, etc.).USEFUL VOLUME. Volume that can becompletely used during operation (typically 80– 90%. of storage volume).YIELD COEFFICIENT. Ratio of therainwater annually flowing into the rainwaterharvesting system to the total amount ofrainwater in the accompanying precipitationarea allowing for leakage splashing,evaporation, etc. (Typically .75 - .90). April 2, 2009 DRAFT for Public Comment 55 of 58 Wednesday, April 1, 2009 DRAFT COPY
    • Wednesday, April 1, 2009 DRAFT COPY GA RAINWATER GUIDELINES MANUAL 51 Georgia Rainwater Harvesting GuidelinesReferencesAbbott, S.E., Ward, A., Heinrich, M., Caughley, B.P., Minimizing Contamination of Roof-CollectedRainwater: A New Zealand Perspective in ARCSA Presentation and Papers, 2008 AnnualConference, 2008 September 16-18, Santa Monica, California.Abbott, Stan. (2008). Microbiological Health Risks of Roof-Collected Rain Water in ARCSAPresentation and Papers, 2008 Annual Conference, September 16-18, 2008, Santa Monica,California.American Water Works Association. (1999) Residential end uses of water. Denver, Colorado:American Water Works Association Research Foundation. 310 p.Barlow, Maude and Clarke, Tony. (2002). Blue Gold. New York, New York: The New Press.Dunnett, Nigel and Clayden, Andy. (2007) Rain gardens: sustainable rainwater management for thegarden and designed landscape. Portland, Oregon: Timber Press, Inc.Georgia Amendments to the 2006 International Plumbing, Appendix I, “Rainwater RecyclingSystems”Gould, J, Nissen-Petersen, E. (1999). Rainwater catchment systems for domestic rain: designconstruction and implementation. London: Intermediate Technology Publications.Kinkade-Levario, Heather. (2007). Design for Water. Gabriola Island, British Columbia, Canada:New Society Publishers.Krishna, Hari. (2001). Rainwater catchment systems in Texas. Proceedings of the TenthInternational Conference on Rainwater Catchment Systems of the International RainwaterCatchment System Association: 2001 September 10-14, Mannheim, Germany.Lancaster, Brad. (2008). Rainwater Harvesting for Drylands and Beyond, Volume 2, Tucson,Arizona: Rainsource Press.Macomber, Patricia S. H. (2001). Guidelines for Rainwater Catchment Systems for Hawaii.Manoa, Hawaii: College of Tropical Agriculture and Human Resources, University of Hawaii atManoa.Stooksberry D. 2008 November 20. (Personal Communication). Athens-Clarke County, Georgia.Texas Rainwater Development Board. (2002). Texas guide to rainwater harvesting. Austin, Texas:Texas Rainwater Development Board. April 2, 2009 DRAFT for Public Comment 56 of 58 Wednesday, April 1, 2009 DRAFT COPY
    • 52 Wednesday, April 1, 2009 DRAFT COPY GEORGIA RAINWATER GUIDELINES MANUAL Georgia Rainwater Harvesting GuidelinesThe Cabell Brand Center. (2007). Virginia Rainwater Harvesting Manual. Salem, Virginia: TheCabell Brand Center.Vasudevan, L. (2002). A study of biological contaminants in rainwater rooftops in Bryan andCollege Station, Texas [Masters Thesis]. College Station, Texas A & M University.Waterfall, P. (1998). Harvesting rainwater for landscape use. Tucson, Arizona: The University ofArizona College of Agriculture and Life Sciences.Rainwater Harvesting Potential and Guidelines for Texas Report to the 80th Legislature Submittedby Texas Rainwater Harvesting Evaluation Committee, Texas Water Development Board,TexasCommission on Environmental Quality, Texas Department of State Health Services, Texas Sectionof the American Water Works Association, Conservation and Reuse Division, Published by TexasWater Development Board Austin, Texas, November 2006WebsitesAmerican Rainwater Catchment Systems Association, www.arcsa.orgInternational Rainwater Catchment Systems Association, http://www.arcsa.org/resources.htmlGeorgia Public Policy Foundation, Commentary for Water Conservation, Pricing TrumpsProhibition by Benita Dodd, http://www.gppf.org/article.asp?RT=20&p=pub/Water/envwateruse040528.htmCenter for Biological Diversity, Tucson passes nations first rainwater harvesting ordinance forcommercial properties by April Reese, http://www.biologicaldiversity.org/news/center/articles/2008/land-letter-10-16-2008.htmlRainwaterharvesting.org, Urban Legistlation, http://www.rainwaterharvesting.org/Urban/Legislation.htmNational Drought Mitigation Center, University of Nebraska, Lincoln, Nebraska, USAThe energy policy act: Assessing its impact on utilities by: Amy Vickers / In: Journal of theAmerican Water Works Association, http://www.cepis.ops-oms.org/muwww/fulltext/repind48/energy/energy.htmThe Low Impact Development Center, Inc., Sustainable Design and Quality Research, http://www.lowimpactdevelopment.org/ April 2, 2009 DRAFT for Public Comment 57 of 58 Wednesday, April 1, 2009 DRAFT COPY
    • Wednesday, April 1, 2009 DRAFT COPY GA RAINWATER GUIDELINES MANUAL 53 Georgia Rainwater Harvesting GuidelinesNatural Resources Spatial Analysis Lab, College of Agricultural and Environmental Sciences, TheUniversity of Georgia, http://narsal.uga.edu/glut/ecoregion.php?ecoregion=5National Weather Service, Southern Region Headquarters, www.srh.noaa.govThe Weather Channel, www.weather.comNOAA Satellite and Information Service, National Environmental Stellite, Data, and InformationService (NESDIS), NCDC: * National Climatic Data Center (NCDC).*H2ouse, Water Saver Home, www.h2ouse.orgManufacturers and Suppliers April 2, 2009 DRAFT for Public Comment 58 of 58 Wednesday, April 1, 2009 DRAFT COPY