Keeping an Eye on Sewage Overflows in False Creek
If you followed our work with the False Creek Water Monitoring Program this summer you know that we dove a bit deeper into how the water quality in False Creek stands up to Canadian Recreational Water Quality Guidelines. And if you checked out our First Season Report, you saw that we were surprised—and relieved—by how often our samples from False Creek West and False Creek Central met the guidelines. Our curiosity was piqued in the fall when we spotted something fishy on November 1st in Stamps Landing.
We are the first to admit that pinpointing a single source of water contamination in False Creek is not an easy task as it is often a combination of various factors, including combined sewer overflows, storm drain outflows, illegal sewage dumping from boats, and rain runoff from impervious surfaces. We do know, however, that today there remain three CSOs operating in False Creek: Granville, Science World, and Stamps Landing.
Here are two key findings for Stamps Landing on November 1st, 2018:
An overflow occurred on November 1st by Stamps Landing ferry dock
While sampling on Thursday, November 1st and conducting our environmental observations of False Creek, we noticed an overflow event by Stamps Landing ferry dock (between the Heather Civic Marina and the Cambie Bridge). November 1st was the second rainiest day since we started the Water Monitoring Program on July 13th (the rainiest day being observed on November 26th).
Watch the CSO overflow video here: https://m.youtube.com/watch?v=jcGhcBywfIg
Our sampling tests revealed high E.coli levels
The sample we took right where the overflow occurred showed high levels of E. coli: 1986.3/ 100 mL. Another site in the area of Stamps Landing came in high as well: Habitat Island’s E. coli levels that day were 1203.3/ 100mL. Habitat Island is located a few dozen meters east of Stamps Landing (past the Cambie Bridge). The rest of the locations regularly sampled had relatively low E. coli counts (below 150/ 100mL).
Swim Guide follows the Guidelines for Canadian Recreational Water Quality. A location meets water quality guidelines and is marked “green” in the Swim Guide when a single sample result is below 400 E. coli/100mL and, if available, the geometric mean of no less than 5 samples collected in the previous 30 days is under 200 E. coli / 100 mL water. A location fails to meet water quality guidelines and is marked “red” in Swim Guide when a single sample result is above 400 E. coli/100 mL or, if available, the geometric mean of no less than five samples collected in the previous 30 days is above 200 E. coli / 100 mL water.
We know that the City of Vancouver plans to eliminate sewage overflows by 2050 but until then, periods of heavy rainfall can still impact the water quality by causing sewage to enter the water before receiving treatment. In the meantime, the City continues to work hard to improve water quality in False Creek by first, offering a free and mobile Pump-Out service for boaters to empty their grey water tanks and, second, separating old combined sewer pipes to prevent the release of sewage in the Creek.
While these efforts demonstrate great strides forward, we intend to conduct sampling in Stamps Landing until a time when sewage overflows are eliminated. Being on the water regularly to monitor sites frequented by recreational water users allows us to identify gaps in information that exist with currently available data.
Discovering the overflow in November during rainy season demonstrates the need for year-round monitoring. Water users recreate beyond the “swim season” of May through September. With our continued year-round monitoring, we can alert the public of overflows on a weekly basis should any be discovered throughout the year.
Water users are on the water year-round, so water quality monitoring should be year-round as well. We know from city reports that sewage spills tend to be more frequent in late fall and winter, so at least one full year of monitoring needs to be completed to get a full picture of False Creek’s health.
Year-round monitoring will allow us to better understand sources of contamination through the winter and spring rainy season and gain a more complete understanding of threats to water quality. This is one of the recommendations that resulted from the First Season Report of our False Creek Water Monitoring Program collecting five months of sampling data in False Creek.