Testing for Water Quality

pH

• Why Test? Changes in pH indicate

the presence of contaminants

• Comments Healthy aquatic

organisms prefer a pH range of 6.0-8.0

Less than 7 = Acidic 7 = Neutral Greater than 7 = Basic

Dissolved Oxygen (DO)

• Why Test? Low DO levels

indicate wastes in the water; unhealthy

• Comments High DO indicates

healthy, well-aerated water

Less than 3 ppm = bad for fish

5-6 ppm needed for growth of fish

Coliform Bacteria

• Why Test? If present, disease-

causing organisms are probably there as well.

• Comments This is a key first

test for water safety.

Not purple = presence of bacteria, bad

Nitrates

• Why test? High nitrates are

harmful to humans; can cause eutrophication

• Comments Nitrates come from

fertilizer, wastewater, and runoff (agricultural).

Less than 4 ppm = good

Greater than 40 ppm = unsafe to drink

Phosphates

• Why test? High phosphate

levels cause eutrophication

• Comments Phosphates come

from agricultural and lawn runoff and detergents.

Greater than 0.03 ppm will encourage algae growth

Total Alkalinity

• Why Test? Measures water’s

ability to neutralize acids

• Comments Loss of buffering

capacity can affect pH

100-200 ppm will stabilize pH

Total Hardness

• Why Test? Excess amounts of

Calcium and Magnesium

• Comments Affects plant and

animal growth rates, hard water can leave deposits and decrease soap suds

Levels 60-120 ppm is medium range

Ammonia

• Why Test? Comes from

bacterial decomposition

• Comments Can be toxic to fish

and is found in areas with a lot of decaying materials

Levels 5-10 ppm are too high

Chloride

• Why Test? Major component of

water and sewage, gives a salty taste

• Comments Salt can affect

plants and animal life

Drinking water should be less than 250 ppm

Chromium

• Why Test? A toxic chemical

from industrial waste

• Comments Can cause cancer in

drinking water Over 0.5 ppm is

untreated waste water

Free & Total Chlorine

• Why Test? Only present in

chlorinated water (sterilized and

disinfected water)

• Comments Swimming pools = 1 to

3 ppm Drinking water = 0.5

ppm Too high is fatal to

plants and fish

Iron (II)

• Why Test? Small amounts is

natural Acid mine drainage

can increase levels

• Comments Greater than 0.2

ppm is generally unacceptable

Copper (I, II)

• Why Test? Small amounts is

natural Industry or pipes

can elevate levels

• Comments Greater than 1.0

ppm will give a bitter taste

Drinking water is usually below 0.03 ppm

Total Nitrite as Nitrogen

• Why Test? High nitrites are

harmful to humans; can cause eutrophication

• Comments Greater than 1 ppm

increased plant growth