Operations and Maintenance of Vegetated Water Quality Facilities
Maintenance of Rain Gardens, Swales, and Stormwater Planters OLCA Expo December 1, 2011
PartnersCandace Stoughton EMSWCDGail Shaloum Clackamas WESRob Emanuel Clean Water ServicesDamon Richardson Pacific Sports TurfHenry Stevens Portland BESMaria Cahill Green Girl Land Development
Agenda• What is stormwater? Why manage it?• Legal issues• Role for landscape contractors• Types of facilities• Maintenance activities • Vegetation • Pests • Irrigation • Soils/Mulch • Structures • Erosion Control • Spills/Trash• Take home messages
What is Stormwater?Photo: morgueFileRainfall and snowmelt that runs off instead of seeping into the ground.
Sources of stormwater? Roofs Driveways Streets Parking LotsRainfall and snowmelt that runs off instead of seeping into the ground.
What is involved?• Facilities need inspection and maintenance (annually, or more)• Maintenance includes: • hydrologic and water quality function • landscape functions • impacts on human health and safety
Business opportunitySpecialized training to design, inspect and maintain • Landscape Architects P • Civil Engineers • Landscape Designers • Landscape Contractors • Green industry professionals Example: City of Portland • 9000 stormwater facilities • ≈ ¼ are LID facilities
Legal roles and responsibilities EPA (US Clean Water Act) ODEQ JurisdictionFacilityOwner Contractor
Inspection log• Each jurisdiction will havedifferent requirements forinspections, reporting, etc.
General observationsBefore you go…• O & M plan or manual• As-built or design report• Locations of inlets/outlets, plantings, irrigation, historical problems, previous observations
General observationsOnce you arrive…• Current and recent weather conditions?• Last rain event?• Inlets and outlets clear?• Banks stable?• Draining as designed or short-cutting?• Pavement in good condition?• Animal damage?• Can you access?• Steep or uneven terrain?• People entering/cutting through the facility?
Contributing area• Trash• Leaves• Oily• Gravel• Sediment• Street or parking lot sweeping• Fertilizer or pesticide use• Other activities going on upstream
Safety and accessPersonal Protective Equipment (PPE)• Sturdy boots• Gloves, puncture resistant gloves• Ear plugs/earmuffs if operating power equipment• Eye protection when “weed wacking” or mechanical trimming, handling large branches• Long sleeved shirts and pants• Hard hat if cutting overhead 35
Safety and accessOther Equipment• Rakes: to clean out under shrubs where you can’t see• Grabbers: for trash, sharp objects, or needles• First aid kit
Safety and accessPublic Safety• Vehicle entrances/exits• Where people walk through, create a path
Trash• Remove trash to prevent clogging and contamination
O&M tasks related to vegetation• Functions• Moving• Appearances• Pests• Irrigation
vegetation can be part of the solution……vegetation can be part of the problem.…..…
Do’s and Don’ts for Plants• Do strive to keep good plant cover in a WQF• Do pay attention to facility design• Do replace dead plants promptly• Don’t overly trim grasses and grass-like plants• Don’t let plants block water flow
Herbicides• Avoid if at all possible!• Follow the label directions carefully• Do not apply in standing water• Try to stay above water-line in facilities• Never apply when rain is forecasted• Apply during calm weather, cool weather
Herbicide use: discretion of local jurisdiction Use herbicides when a pest isuncontrollable by other, less toxic means.
Herbicides• DON’T reach for herbicides at the first sign of a pest, make a plan!• DON’T apply herbicides directly to water in a WQF• DO apply herbicides during dry weather (mostly June-September)• DO apply herbicides when a pest is uncontrollable by other means
Irrigation P• Plants are critical to the function of LID facilities• Irrigation is essential for plant establishment and health
Irrigation• Irrigation especially important during establishment period (approx. 2 yrs) (true for native plants as well) P• Temporary irrigation fine for facilities with vegetation that can handle OR’s dry summers
IrrigationHigh exposure areas can also require permanentIrrigation after the establishment period. P• Areas near pavement• Vast areas of minimal shade or lots of wind exposure• areas prone to drought or fire
IrrigationWater Efficiency• Hand watering and drip type irrigation systems P are the most efficient irrigation methods.• Adjusting the irrigation heads should be done as needed to ensure water is not wasted on hard surfaces.• Avoid irrigating when the plants do not need water.
IrrigationHow to Irrigate• Water must be applied in a manner that lets it P percolate into the soils and not run off the surface.• Hand watering- Put as much down as possible until water begins to migrate along surface. Then go to the next plant.Automated Systems• Permanent• Temporary• Utilize several short watering times or cycle/soak.
Irrigation for Plant Establishment1st YearFull irrigation schedule during the dry season to Pensure good plant establishment.2nd YearWater less than previous year to encourage plants toadapt to local climate.3rd YearShould be little need for irrigation.
IrrigationDo:• Irrigate heavily but infrequently P• Water in the early morning or evening• Automate if possible• Check automated systems weekly during the heavy irrigation season• Blow out any above ground system to winterizeDon’t:• Allow runoff• Over water• Allow overspray• Irrigate when unnecessary
Soils• Healthy soils hold water, sediment, and pollutants• Too much sediment (and compaction) will clog the system• Regular maintenance will keep the facility working as designed City of Portland Environmental Services
Soils• Visit the facility at least twice a winter after big storms• Check sediment accumulations as you’re doing routine maintenance• Monitor draw-down rates – how long does it take for standing water to disappear after the end of a storm ?• Make notes for future reference
When do You Need to Remove Sediment ?• If 2-3 inches of sediment accumulates• When draw- down rates exceed about 36 hours• Don’t let things City of Portland Environmental Services get out of control (photo)
When do You Need to Remove Sediment ? City of Portland Environmental Services
Soils: Removing Sediment• Schedule all maintenance for dry weather unless there’s an emergency• Rakes and shovels (hand removal) are best to avoid damaging the plants• Be sure to loosen the underlying native soil• If large equipment is needed avoid compacting the soils• If slow infiltration rates persist, remove the top couple of inches of soil
When to Be Concerned….Nccwep.org waynedaley.com
Soils: Sediment and Soil Disposal• Check for evidence of contamination: color and smell• In most cases stormwater sediment is not hazardous and can be disposed of as solid waste.• Places to be concerned: recycling facilities, fueling stations, industrial storage areas, etc.• If you have questions, contact DEQ at 503-229-5263.• Or consult DEQ’s guidelines for hazardous waste at http://www.deq.state.or.us/lq/hw/hwmanagement.htm
Mulch• Suppresses weeds and maintains soil moisture• Is a surface for deposition of sediment (for easy sediment removal)• Apply 2-3 inches after planting, after removing sediment, and any time there are bare spots• Common mulches: medium hemlock,yard- debris compost. Gravel “mulch” is sometimes used at entrances Maria Cahill
Mulch• Mulch sometimes floats in the first storms just after construction.• Yard debris compost is less prone to floating, but it can be a source of weeds Maria Cahill• Many LID systems are densely planted and need only spot- mulching after the first couple of years
Do’s and Don’tsDo• Visually monitor the facility on a regular basis• Remove sediment when it reaches 2-3 inches• Plan to take action if drawdown times exceed 36 hours• Mulch and plant bare spots for erosion control• Loosen the soil after removing sedimentDon’t• Compact the soils by working in the facilities when the soils are wet (wait until summer)• Assume a facility is permanently clogged until steps have been taken to remove sediment layers• Handle soils that smell or look odd (contamination)
Structures Prevent Erosion• Rip rap vs. no erosion prevention
Structures Dos and Don’tsDo’s• Do remove sediment, debris & trash from inlet & outlet structures such as curb cuts, rip rap, sumps & grates.• Do control and handle the removed sediment so it won’t get back into the storm system.• Do prevent excessive ponding by inspecting underdrains.• Do prevent flooding by clearing outlets of obstructions.• Do protect the integrity of structures such as curbs, & walls.• Do inspect less durable materials more often.
Structures Dos and Don’ts• Do inspect culverts to look for UV degradation, cross-section shape changes that may cause flooding, and corrosion.
Erosion Prevention• Erosion prevention is any practice that protects the soil surface and prevents the soil particles from being detached by rainfall or wind.
Sediment (aka Source) Control• “Sediment Control is any practice that traps the soil particles after they have been detached and moved by wind or water”…
Sediment (aka Source) Control• …to prevent this! Photo excerpted from “ODEQ Erosion and Sediment Control Manual”, DEQ, Apr 2005
Sediment Control for Sheet Flow Compost Socks
Sediment Control for Sheet Flow Wattles (are your friends!)
Sediment Control for Concentrated Flows Inlet Filters
Sediment Control for Concentrated Flows Protecting Catch Basin Inlets
Erosion Prevention & Sediment Control Dos and Don’tsDo’s• Do prevent erosion by keeping soil covered and getting plants established.• Do prevent erosion by staying out landscape areas when possible. This also prevents soil compaction, which slowly kills vegetation and creates erosion long-term.• Do control sediment when erosion cannot be prevented by using wattles & filter sacks.
Clean up the spillDo• Determine what type of material has spilled• Block stormwater inlets• Use absorbent material to contain the spill• Remove contaminated soil from facility• Protective gear for workers
Clean up the spillDon’t:• Dispose of hazardous material in the garbage. Must be taken to a hazardous waste facility.
Notify the appropriate authoritiesDo• Contact owner of the facility Photo: morgueFile• Contact local jurisdiction emergency response• Contact OR Emergency Response 800-452-0311
SpillsDo• Document the spill in the O&M report
Take Home Messages• These recommendations are general guidelines• Check with the local jurisdiction for specific requirements• Operations and Maintenance guidance document being developed for our region• For more information, contact: email@example.com