Complex Effluents

Question 1

What are complex effluents?

Answer 1

water mixed with natural and man made wastes

Question 2

What are the two main sources of effluents?

Answer 2

municipal wastewater (sewage) and metal mines

Question 3

What pollution is present in MWW?

Answer 3

organic waste, suspended solids, nutrients, pathogens and 100s of chemicals

Question 4

How much waste water do municipal wastewater treatment plants emit annually in Canada?

Answer 4

5.7 billion m3

Question 5

What are the impacts on aquatic environments from MWW?

Answer 5

increased nutrient levels (algae), destruction of habitat (sedimentation and chemical contaminants) and decreased dissolved oxygen (fish kills)

Question 6

What are the impacts of MWW on human health?

Answer 6

loss of recreational area due to bacterial contamination, loss of fishing and drinking water

Question 7

What is an example of MWW failure that occurred in Saskatchewan?

Answer 7

Cryptosporidium parvum infected 5800-7100 people in North Battleford due to improperly treated sewage water

Question 8

What are the two sources of MWW?

Answer 8

sanitary sewage and stormwater

Question 9

What is the federal legislation that municipals must follow for MWW treatment?

Answer 9

Canadian Environmental Protection Act 1999

Question 10

What occurs in prelimary and primary water treatment?

Answer 10

Prelim-screening (no actual cleaning)
Primary: removal of sedimenation

Question 11

What occurs in secondary water treatment?

Answer 11

chlorine treatment for biological wastes like phosphorus

Question 12

What occurs in tertiary water treatment?

Answer 12

removal of bacteria, suspended solids, specific toxic compounds or nutrients

Question 13

What is WET?

Answer 13

The provincial standards of toxicity tests of undiluted effluent required to permit release of effluents that have potential to cause harm on aquatic environments

Question 14

What are the three types of tests used for WET?

Answer 14

Acute (LC50) and EC50 and NOEL tests

Question 15

What organisms are used for each tests?

Answer 15

LC50-rainbow trout and mysidopsis bahia
EC50/NOEL-fathead minnow, arbacia punctulata, ceriodaphnoa dubia and fathead minnow

Question 16

What is the WSER?

Answer 16

Canadian Wastewater Systems Effluent Regulations

Question 17

What are the regulations regarding BOD and suspended solids according to WSER?

Answer 17

BOD: less than or equal to 25mg/L
SS: less than or equal to 25mg/L

Question 18

What are the regulations regarding residual chlorine and unionized ammonia according to WSER?

Answer 18

Cl: less than or equal to 0.02mg/L
NH4: less than 1.25 mg/L

Question 19

What is TRE?

Answer 19

Toxicity Reduction Evaluation-in place after a failed WSER test, identifies problem and removes it

Question 20

What metals is Canada in the top 5 producers in the world for?

Answer 20

Nickel, zinc, cadmium, aluminum, gold, platinum, copper, cobalt and lead

Question 21

What do WWTP treat for in mining effluents?

Answer 21

toxic metals/chemicals, total suspended solids, dissolved organic carbons and controls pH of effluent (6-9)

Question 22

What are the impacts of the metal industry on aquatic environments?

Answer 22

sedimentation and turbidity-decreases light and overall biological productivity and destroys habitat
acidification-bioaccumulation of metals in fish and benthos and pH>5 no fish breeding, <6 lethality to sensitive populations

Question 23

What is the Canadian EEM program?

Answer 23

Environmental Effects Monitoring Program-tests done every three years to evaluate any effects of metal effluence of fish and overall aquatic environment

Question 24

What is tested in the EEM for in fish?

Answer 24

survival-age
energy use-size at age (growth) and relative gonad size
energy storage-relative liver size

Question 25

What is tested in the EEM for fish habitat?

Answer 25

diversity and biomass of populations