Victoria`s wastewater discharges: Effects on the marine environment
- Capital Regional District, Victoria, British Columbia (Canada)
The Capital Regional District discharges screened wastewater through two long deep outfalls into Juan de Fuca Strait, a water body bordered by both Canada and the US. Concerns have been expressed about the effects of this discharge on water quality in US waters. The wastewater is released into an oceanic environment characterized by strong turbulent tidal flows. Monitoring of the receiving waters has indicated that conventional water quality parameters have not been affected by the discharges. Fecal coliform levels above the outfalls are periodically elevated but remain well below the swimming standard. Shoreline studies of fecal coliform levels have shown that the deep outfalls have not measurably affected water quality at beaches. Recently, monitoring efforts have concentrated on effects to the seafloor environment. One of the outfalls (Macaulay Point) discharges to a depositional environment. At Macaulay Point chemical levels of concern were confined to within 100--400 m of the outfall with the exception of high PAH levels associated with the shipwreck of a collier. Similarly, sediment toxicity was detected at stations up to 400 m from the diffusers. This toxicity was limited to effects on growth and development. Survival was not affected. The benthic infaunal community exhibited a typical response to organic enrichment. Within 100 m of the outfall abundance was increased and richness depressed. The other outfall (Clover Point) discharges to an area of cobble substrate. Consequently, sediment analysis was not practical. Instead, tissue chemistry of resident mussels was examined. No consistent pattern with distance from the outfall was evident. Some tissue chemicals increased with distance from the diffuser while others decreased. Overall the impact of the outfalls on the seafloor was found to be minimal and restricted in extent.
- OSTI ID:
- 197558
- Report Number(s):
- CONF-9511137-; ISBN 1-880611-03-1; TRN: IM9612%%332
- Resource Relation:
- Conference: 2. Society of Environmental Toxicology and Chemistry (SETAC) world conference, Vancouver (Canada), 5-9 Nov 1995; Other Information: PBD: 1995; Related Information: Is Part Of Second SETAC world congress (16. annual meeting): Abstract book. Global environmental protection: Science, politics, and common sense; PB: 378 p.
- Country of Publication:
- United States
- Language:
- English
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