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