CHEMICAL WATER QUALITY What is water quality?
ASSESSMENT TRAINING Federal Clean Water Act, 1972 states
“The objective of the Clean Water Act is to
restore and maintain the chemical, physical, and
Ohio’s Volunteer Monitoring Training Program
Ohio’ biological integrity of the Nation’s waters.”
Ohio Environmental Protection Agency,
Ohio University’s Voinovich School of Leadership and
Day 1, 2009
What is water quality? Chemical water quality
Physical Chemical Biological
Temperature pH Bacteria What parameters to sample
Suspended solids Dissolved oxygen Algae Where and when to sample
Turbidity Nutrients Fish
Field measurements vs. laboratory samples
Water color Acidity Macroinvertebrate
Analytical Methods (Appendix C)
Stream substrate Alkalinity
What parameters to sample? Parameters
• Common field •
parameters are: Important because it affects the rates of many
of the biological and chemical processes in
• Temperature Conductance the water.
• Turbidity • Fecal indicator Important for determining DO, pH, and
• Dissolved oxygen
Essential in documenting thermal alteration
of a system.
Field measurement: A liquid in glass
thermometers or probe
Turbidity - describes how the particles suspended Dissolved oxygen (DO) - is the measure of the
in the water column affect its clarity. amount of oxygen in the water.
Soil particles, algae, or other substances such as Necessary for both biological and chemical
suspended metals in the water most often cause processes in the water.
turbidity. Its presence (or lack of) is also important
Turbidity is expressed in intensity of light scattered by information for the design of water treatment
particles in the water.
DO is measured in mg/l or as the percent of
Turbidity can be measured using a turbidimeter.
turbidimeter. saturation, which is dependent on water
Monitoring the effects of runoff and help develop temperature.
trends in increased erosion in a watershed over time. Usually measured with titration (field or lab)
or DO sensor (field only)
pH - is controlled by the interrelated chemical Total Alkalinity - is the measure of the
reactions that produce and consume hydrogen capacity of the water to neutralize acid.
ions. It is a measure of hydrogen ion activity in In streams heavily effected by acid both
the water. alkalinity and acidity may be present or only
• Critical factor in many chemical and biological acidity with no alkalinity to buffer it.
processes in a stream. Alkalinity is typically reported as mg/L of
• pH is measured on a scale of zero to 14
Standard pH units calcium carbonate (CaCo3). It is an aggregate
• pH probes, indicator strips, measure of the total amount of bicarbonate,
•color wheels, etc…
etc… carbonate, and hydroxide ions.
Phosphorous - is one of the foundations for
Total Acidity - is the measure of the excess of the food web of a river system. It rarely is
hydrogen ions over basic ions. found in nature as pure elemental phosphorus,
Total Acidity is expressed in mg/L. When but more often as organic or inorganic
the buffering system is unable to react phosphate.
anymore, usually at a pH of 4.2, the stream or
• Inorganic phosphates are those that are readily available and needed by
water body becomes acidic. plants.
• Organic phosphates are commonly
used in detergents/soaps.
• Excess phosphates cause
“sudsy/foamy” looking water.
Nitrate - is the form of nitrogen essential to ORP- Oxidation Reduction Potential provides
plant growth and building proteins. a measure of the water’s oxidizing or reducing nature.
It is useful to assign a value to a reducing or
Excess nitrates lead to increases in plant growth.
oxidizing environment. The oxidizing nature of
They are a good indicator of raw sewage or excess water has an implication on the ability of water to
fertilizer in a stream system. support life and on the waters corrosive properties.
In the field nitrates are generally measured with ORP is measured with a hand held probe and is
titration kits and a color index recorded to the nearest millivolt. Temperature
should also be recorded when taking ORP
Specific Conductance is the measure of the Fecal indicator bacteria - are different
ability of water to pass an electric current. types of bacteria that are common and can be
It is very useful as a general measure of water quality. used as an indicator of raw sewage in a stream.
It is a function of the types and quantities of Most commonly monitored are the bacteria that
dissolved substances in the water. are associated with pathogenic organisms
The basic unit of measurement is microsiemens per including:
centimeter (μS/cm) Total Coliform
Specific Conductance is most commonly measured Fecal Coliform
with conductivity probes/meters.
Escherichia coli (E. coli)
Total Coliform –fecal coliform and other non-non-
fecal bacteria (just for drinking water purposes)
Fecal Coliform – a subset of total coliform
more directly related to feces (raw sewage
residential or animal waste)
Escherichia coli (E. coli) – is fecal
bacteria specific to human or other warm
blooded animal feces (best indicator for
human health risk)
Where to sample When to sample
The sampling point is selected based on the Criteria to consider:
specific information to be obtained. Stage (base flow, high flow, low flow)
Discrete discharge - as close to the source as possible.
Tributary mouth - upstream far enough that mainstem water is Seasonality
not influencing the water quality. Current rainfall conditions
Two sources of water are mixing - the sample is taken in a
Frequency of samples to be collected at each
location where sufficient mixing has occurred.
Take the sample where velocity is sufficient at a
Sampling strategy dependant
distance from the banks (in the middle of the
current if possible). Long-term monitoring, reconnaissance,
Site Description Site Description
Useful for return sampling events Record a general description:
Monitoring changes through time Qualitative – reference to a permanent feature
Record the following: Physical including: visible pollution sources,
The landowner and contact info, conditions of the riparian zone, banks, stream
Permission for access and access instructions, characteristics (color, odor, substrate,
Name of road, township, county vegetation, canopy, water depth/level, recent
Mark sample location as accurately as possible on a
topographic map and record GPS
weather conditions, etc….
Mark the sample location with survey tape.
Site Numbering Sampling Methods
Site numbering is essential to allow each Field measurements should represent the natural
individual site location to have a unique identity. condition of the surface water system at the time
On the following page 19 is an example of of sampling.
Ohio EPA’s river mile numbering convention
EPA’ Appendix C of the Administrative Code 3745-4-
05 provides a table of acceptable analytical
methods for Level 1 and 2 credible data
Sampling methods Sampling methods
Calibrate instruments Stabilization Criteria
Test instruments Temperature +/-0.2 deg C
Stabilize instrument Conductivity <100 mS/cm +/- 5%
Repeat sampling for accuracy >100 mS/cm +/- 3%
PH +/- 0.1 unit
DO +/- 0.3 mg/L
Turbidity +/- 10%
Sampling Methods Sampling Methods
Water quality samples types for laboratory
Nitric Acid (cation/anions)
Sulfuric Acid (nutrients)
Hydrochloric Acid (ferrous iron)
No Preservatives: (Bacteria, pH, Alkalinity,
Conductivity, Total Suspended Solids, etc…)
Under turbid conditions
Excess metal particulates suspended in the water
Sampling Methods Field safety
Shipping and Transport Safety issues with sample collection and the appropriate
use and disposal of materials.
Read the accompanying materials safety data sheet
Sealed in water tight bags with ice (MSDS).
Packed in coolers (4 degrees Celsius) When using chemicals wear gloves and goggles.
Chain- of- Carry first aid kit and eye washing liquids.
When handling surface water, be certain not to have contact
Holding times with open sores or cuts.
Do not sniff, taste, or touch chemicals.
Dispose of all chemicals and containers using MSDS
Keep MSDS available for easy use.
Wash hands thoroughly when done.
Field Safety Field Sessions
Avoid dangerous situations. High flow in streams can be deceiving
deceiving Equipment calibration, maintenance, and
in its depth and its force. Do not attempt to enter a stream during
Wear appropriate clothing like hip or chest waders Chain-of-custody forms, QAQC, and holding
Good foot wear for walking on slippery banks and rocks. times
Life jackets are suitable precautionary equipment. Demonstration of field parameters
Be aware of poisonous vegetation and dangerous animals. measurements
Be aware of traffic Demonstration of water
Always wear rubber gloves in known or suspected sewage impacted quality sample collection
Wash your hands thoroughly when done. Carry hand sanitizer if Teams practice using
hand-washing facilities are not nearby.
hand- equipment and sampling
Sample with a partner.