1. Water Testing
APES

2. Lab Investigations for APES

3. Know the basis for each test and what the test measures.

4. Dissolved Oxygen (DO)
BOD (Biological Oxygen Demand)
Total hardness
pH and total alkalinity
Nitrate / nitrite nitrogen
Turbidity (Total Suspended Solids)
Fecal Coliforms

5. Dissolved Oxygen (DO) Atmosphere = 200 mL/L Water = 5-10 mL/L
Temperature is a factor
Cold water can hold more DO
Salinity is a factor
Fresh water has higher DO than salt water
Elevation is a factor
Water at higher elevations contains less DO due to air pressure
Aeration = Churning/disturbing the water adds DO

6. DO Nomogram
Water temp of 10 C and 9ppm Oxygen = 80% saturation

7. FYI: ppm = mg/L

9. BOD (Biological Oxygen Demand)
Aerobic microorganisms (including bacteria) decompose organic matter in a water source.
As they do, they use up a lot of the oxygen in the water, thus creating an oxygen sag.
High BOD indicates lots of organic matter that will put a strain on oxygen supplies.

10. The plant we visited influent = 274 mg/L effluent = <2.0 mg/L

11. Water Hardness (Total Dissolved Solids, TDS)
Measure of the amount of DISSOLVED solutes in the water, typically salts, metals, cations, anions, (Calcium and Magnesium are common)

12. pH and total alkalinity
Total alkalinity is the total concentration of bases in water expressed as parts per million (ppm) or milligrams per liter (mg/L) of calcium carbonate (CaCO3).
Ideal pH is around 7 or slightly higher
Aquatic life is sensitive to acids or strong bases

14. Nitrates/Nitrites Once again, measured in mg/L
Nitrates (and phosphates) are limiting factors of aquatic organisms.
Excessive Nitrates cause blooms.
The decomposition of the dead blooms consumes most of the oxygen creating a dead zone (EUTROPHICATION)

16. Turbidity (Total Suspended Solids, TSS)
Measure of the amount of particles suspended in the water. Do not settle or dissolve.
“Murkiness”
mg/L - higher the number, more murky
Decreases amount of light penetrating the water for photosynthesis
Particles can absorb heat, increasing temperature, lowering DO

20. Turbidity Removal
In general, surface water will need pre-treatment to reduce turbidity before it is disinfected (Wisner, 2002). Treatment methods which reduce turbidity include sedimentation, roughing filters, rapid and slow sand filters, chemical coagulation and flocculation, and ceramic filters.

21. Fecal Coliforms Measure of the amount of fecal coliforms per 100mL
Organisms / 100mL
Not necessarily harmful, but high levels indicate a failure of waste water treatment or contamination from animal waste
Increased risk of water-borne illness

23. Turbidity Removal
In general, surface water will need pre-treatment to reduce turbidity before it is disinfected (Wisner, 2002). Treatment methods which reduce turbidity include sedimentation, roughing filters, rapid and slow sand filters, chemical coagulation and flocculation, and ceramic filters.

25. Secchi disk