Chemical Testing

Collecting Water Chemistry Data to determine levels of pollution

How healthy is the water?

Citarum River in West Java, Indonesia

• Pollution: anything entering or occurring to contaminate a water source that is not the result of a natural process.

• Unpolluted Water: water that is comprised of a natural balance of chemicals and nutrients which aid in life and growth of aquatic organisms.

Ammonia

Can be either toxic as un-ionized NH3 or nontoxic as ionized NH4

Amount of each present is regulated by pH and Temperature

Sources: Animal Excretions, Fertilizers, cleaning productsoBacteria process proteins and urea

creating ammonia

Ammonia

Highly toxic in even small concentrations

Unpolluted Stream: Less than 1 ppm Associated with low DO and increase

decaying organic matter

Dissolved Oxygen (DO)

• The amount of oxygen water is receiving and able to retain

• The higher the DO, the better the water quality

• Unpolluted Streams: 5-6ppm • Polluted Stream: 1-2 ppm• Trout require DO levels >6ppm

Dissolved Oxygen (DO)

Higher DO if• Lower Water Temp • More Turbulence (rifles)• More PhotosynthesisOxygen Demanding Wastes• Certain wastes can trigger increases

in bacteria which depletes DO

BOD – Biochemical Oxygen Demand

A measure of the quantity of DO used by bacteria as they break down organic wastes

Unpolluted Streams: 5 mg/L or lessoWastewater Treatment Plants have BOD

levels of 150-300 mg/L and must reduce them to 8-150 mg/L depending on the discharge permit

Chromium

Chromium is a heavy metal and toxic chemical

Unpolluted Stream: less than 0.5 ppm

Sources: oMetal PlatingoOverflow from Air Conditioning UnitsoHousehold ChemicalsoRunoff

Chromium

Can be found in the mud at the bottom of a lake or stream

Can be accumulated by certain fish Damages the liver, kidneys, and

nervous systems, is carcinogenic “Biomagnification”

Hexavalent Chromium (Chrome-6) was the pollutant in the famous “Erin Brockovich Case”

pH (Concentration of Hydrogen ions)

A measure of acid or alkaline on a scale of 0-14, 7 being neutral

Unpolluted Streams: 6.5 – 8.5 Acid Rain can lower the pH of a

stream system Farm runoff (specifically lime) can

increase pH Increased photosynthesis can

increase pH

Alkalinity

Ability for water to neutralize acids – called buffering

Unpolluted Stream: 100-200 ppm of CaCo3 (Calcium Carbonate)

Sources: carbonate rocks (limestone/marble) and soils

Limestone streams of Penna are home of world-class trout fishing

Chloride

A form of chlorine dissolved in water – usually as a molecule (NaCl, HCl)

Sources: Dissolved Salt Formations, Salt Water Intrusion, Residential/Industrial Pollution

Can be used to determine Salinity Unpolluted Streams: less than 250

ppm

Phosphates (PO4-3)

• Phosphates are necessary for plant growth and are common ingredients in fertilizers

• Unpolluted Stream: less then 0.1 ppm

• Waste Water: 5-30 ppm

Nitrates (NO3)

• Nitrates are necessary for organisms to repair cells and are common ingredients in fertilizers

• Unpolluted Stream: Less then 10 ppm

• Drinking Water Standard: less than 40 ppm

Phosphate and Nitrate Enters the water system

from:• Fertilizer

– Content: N-P-K• (Nitrogen-Phosphorous-Potassium)• Relative Percentage per bag: Ex. 10-10-10

• Industrial Wastes• Sewage• Detergents• Weathering of Bedrock• Decomposition of Organic Matter

Eutrophication

• process by which young lakes age into swamps and eventually dry land

• Cultural Eutrophication– The acceleration of the normal aging of

a lake due to human activities– Usually the introduction of nitrates and

phosphates into a water source

The process:

• Nutrients enter the water system• Triggers increased growth of algae (algal

bloom) and aquatic plants• Increased algae and plants causes an

increase in bacteria• Bacteria breakdown and feed off the

decaying algae and plants depleting the oxygen levels

• Eventually, the reduced DO levels suffocate oxygen loving organisms

Chesapeake BayAlgal

Blooms

April 20,2005