BC Clean Ocean Initiative

– FISH TOXICOLOGY TESTS –

Rainbow trout were tested in 1992 for lethal effects of Macaulay Point and Clover Point effluent in 96-hour LC50 tests. The LC50 test determines concentrations of effluent that result in 50% mortality of the test organisms. The results demonstrated that, on average, concentrations of 55% effluent (specifically, 55 litres of sewage effluent mixed with 45 litres of clean salt water), resulted in 50% mortality to rainbow trout. Any concentration other than 100% effluent is considered failure of the LC50 test.[1] That is, effluent is considered to be acutely toxic if the concentration of effluent that causes 50% mortality is ≤100%. The effluent is considered to be not toxic if <50% mortality occurs in fish exposed to 100% effluent.

Rainbow Trout (96-hour LC50) Toxicity Testing 1

Concentration of Macaulay Point effluent resulting in 50% mortality to trout

Concentration of Clover Point effluent resulting in 50% mortality to trout

May 1992

42%

56%

July 1992

56%

64%

In 1998, rainbow trout toxicity tests using 100% Victoria effluent, demonstrated that all fish were dead within 24 hours of exposure. For the Macaulay Point effluent, all fish were dead within the initial 30-minute observation time. Both samples had been aerated for 2 hours prior to testing.[2]

The results from toxicity testing (96-hour LC50) on salmonids in 2004, 2005, and 2006 reported concentrations between 24% and 5.9% of effluent, with the lowest concentration observed in 2006. When compared to effluent from the Sooke treatment plant, Macaulay Point and Clover Point effluents were much more toxic. It should be noted that 68.9% Sooke effluent was the maximum concentration of effluent used in this test.[3]

Salmonoid (96-hour LC50) Toxicity Testing 3

Concentration of Macaulay Point effluent resulting in 50% mortality to Salmonids

Concentration of Clover Point effluent resulting in 50% mortality to Salmonids

2004

24%

13%

2005

24%

10%

2006

19%

6%

In 2008, 100% survival in Salmonids was reported in 96-hour LC50s with 68.9% of effluent from the Sooke treatment plant. 68.9% was the highest concentration that could be tested due to the adjustment of the sample to 29 ppt salinity with 90 ppt brine.

– MUSSEL & OYSTER TOXICOLOGY TESTS –

In 1992, toxicity testing using Macaulay Point and Clover Point effluent evaluated the development of mussel and oyster embryos (48-hour EC50 test). The EC50 test determines the concentrations of effluent that result in abnormal development of 50% of the mussel or oyster embryos. The results demonstrated that, on average, 2.5% effluent (specifically, 2.5 litres of effluent mixed with 97.5 litres of clean water in the laboratory) caused abnormal embryo development. At this concentration 50% of the mussel and oyster embryos developed abnormally. Concentrations at levels as low as 1.1% effluent (from Clover Point) caused abnormal development in 50% of the organisms.[4]

Mussels and Oysters (48-hour EC50) Toxicity Testing 4

Concentration of Macaulay Point effluent resulting in abnormal development in 50% of the mussel and oyster embryos

Concentration of Clover Point effluent resulting in abnormal development in 50% of the mussel and oyster embryos

May 1992

3.2%

3.9%

July 1992

1.7%

1.1%

“At Clover Point, mussel tissue monitoring for chemical bioaccumulation shows that levels of a number of substances (for example, copper and lead) are elevated in mussels at the outfall (and in some cases, at both the near-field and far-field stations), compared to the reference stations.” [5] The Clover Point outfall also had polychlorinated biphenyl (PCB) concentrations in mussel tissue that were almost double that of the far-field stations.

The results of various published Vancouver Island studies have shown that chemicals associated with Victoria’s sewage are toxic to marine organisms. For example, a dramatic increase in abnormal blue mussel embryo development was observed at copper concentration of 10 µg/L – there were four times more abnormalities observed at that concentration than in the unexposed embryos. At concentrations of 100 µg/L copper, 100% of the embryos showed abnormal development.[6] By comparison, copper concentrations from the Clover Point and Macaulay Point Outfalls averaged 119 µg/L between 2000 and 2004. These levels have spiked to as high as 1500 µg/L at the Macaulay Point Outfall, with the lowest measured level being 48 µg/L.[7]

– ENDOCRINE DISRUPTING CHEMICALS –

“Endocrine disruption chemicals are compounds that alter normal functioning of the endocrine system, potentially causing disease or deformity in organisms and their offspring.”[8] There is extensive evidence that sewage effluent can affect reproductive endocrine function in fish and contribute to alteration in reproductive development.[9]

There are several pathways through which endocrine disruptive chemicals end up in sewage. For example, estrogen, an ingredient in contraceptive pills is excreted in human urine. Plasticizers, such as phthalates, can originate from industrial wastewater or landfill leachate that is collected in stormwater or discharged to the sewer system. These types of chemicals are also found in human urine and breast milk.[10]

Studies conducted in B.C. show that environmentally-relevant sewage concentrations (0.05%, 0.1%, and 0.7% effluent in seawater) caused gene expression alterations in juvenile Chinook salmon. Such alterations at the molecular level can result in feminizing juvenile Chinook salmon and is probably due to an additive effect of the mixture of compounds in the sewage. Sewage from sources in B.C. was used in these tests.[11]

“Aquatic species are most affected by endocrine-disrupting chemicals, but effects have also been observed in terrestrial animals. A syndrome of embryonic abnormalities has been observed in fish-eating birds and can be directly related to polychlorinated biphenyl (PCB) exposure.”9

Data from 18 municipal plants across Canada showed that treatment resulted in a decrease in the endocrine disruptors, estrone and 17b-estrodiol. On average 71% of estrone and 88% 17b-estrodiol were removed from sewage and municipal effluent through treatment.[12]

” […] the efficiency of removing various EDCs in sewage treatment plants is quite high (generally around 80%) for nanylphenolethoxylate and estradiol (Ternes et al. 1999)”[13]



[1] Golder. Potential environmental effects of the Macaulay and Clover Point outfalls and review of the wastewater and marine environmental program, 2005

[2] EVS Environment Consultants. Toxicity Testing on Samples Identified as Project X2 MC and Project X2 CL (Both Collected March 23, 1998), 1998

[3] Environment Canada (DOE) Toxicity Testing Lab unpublished data

[4] Golder. Potential environmental effects of the Macaulay and Clover Point outfalls and review of the wastewater and marine environmental program, 2005

[5] SETAC. Scientific and Technical Review, 2006 pg.13&14

[6] Fitspatrick JL, Nadella S, Bucking C, Balshine S, Wood CM. The relative sensitivity of sperm, egg and embryos to copper in the blue mussel (Mytilus trossulus), Comparative Biochemistry and Physiology, 2008. 147: 441- 449

[7] Golder. Potential environmental effects of the Macaulay and Clover Point outfalls and review of the wastewater and marine environmental program, 2005

[8] McKinlay R, Plant JA, Bell JNB, Voulvoulis N. Endocrine disrupting pesticides: Implications for risk assessment, Environment International, 2008. 34; 168-183

[9] Damstra T, Barlow S, Bergman A, Kevlock R, Van Der Kraak G, editors. World Health Organization. Global assessment of the state-of -science of endocrine disruptors. International programme on chemical safety. 2002 (WHO/PCS/EDC/02.2) pg.2

[10] Markman S, Guschina I, Barnsley S, Buchanan K, Pascoe D, Müller C. Endocrine disrupting chemicals accumulate in earthworms exposed to sewage effluent, Chemosphere, 2007. 70; 119-125.

[11] Osachoff H, Toxicogenomic effects of sewage on juvenile Chinook salmon (Oncorhynchus tshawytscha), Simon Fraser University. 2008

[12] Servos MR, Bennie DT, Burnison BK, Jurkovic A, McInnis R, Neheli T, Schnell A, Seto P, Smyth SA, Ternes TA. Distribution of estrogens, 17b-estradiol and estrone, in Canadian municipal wastewater treatment plants. Science of the Total Environment 2005, 336; 155-170

[13] Dizer H, Fischer B, Sepulveda I, Loffredo E, Senesi N, Santana F, Hansen P. Estrogenic Effects of leachates and soil extracts from lysimeters spiked with sewage sludge and reference endocine disrupters 2002; 105-112