Water quality study examines wastewater flow

Published on Thu, Nov 15, 2012 by Brandy Kiger

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If you’ve noticed a reddish cloud moving through the water in Semiahmoo Bay over the past two weeks, there’s nothing to worry about. It’s just part of an ecological study that the Lighthouse Point Water Reclamation Facility (LPWRF) has been hosting in order to determine the impacts of their output on the environment. 

The LPWRF dumps, on average, a little more than half a million gallons of treated wastewater into the bay each year. The water is processed using an advanced membrane bioreactor (MBR) to sanitize it and remove any harmful substances before it is released from the facility. “This place does wonders compared to conventional wastewater plants,” said spokesperson Christina Ness, adding that the advanced treatment the water receives before being released back into the bay takes out nearly everything as far as conventional pollutants go. “We get really good removals, around 99 and 100 percent,” she said.  

The multi-jurisdictional water study, which was conducted by the U.S. Food and Drug Administration, Washington Department of Ecology, Washington Department of Health, Lummi Nation and City of Blaine, is the first of its kind. “They go around and do [research] worldwide, but they’ve never studied a process like this before,” Ness said. “The literature says everything is clean, but they had to find out for themselves.” 

For this study, Rhodamine WT dye was added to the effluent during the week of November 4 so that researchers could track how far reaching the dispersion of the effluent was and what effect it had on the environment. They then watched the plume over a 10-day period, measuring and documenting its progress. “[The FDA] was quite impressed after the study,” Ness said. “They were amazed at the clarity of the effluent and the clarity of the bay around our outfall. We’re kind of optimistic about the results.” She noted that the researchers could see the dye coming out of diffuser point 37 feet down – an unheard of depth for effluent to be visible.

And while the plume of red dye and the researchers with their boats are gone, the study is still ongoing. Beds of oysters, bought from a commercial grower, still await testing. They’ll be harvested after Thanksgiving so that they have plenty of time to collect anything that might be dispersed in the water and then compared with a control specimen that’s being kept on ice at the facility. The comparison will allow researchers to see what the oysters have been exposed to in the bay and identify if any viral or bacteriological loading has been caused by the plant. 

“The initial report was that everything looked pretty good,” Ness said. “We just have to wait.”

The results of this study will be presented in a technical paper to the Environmental Protection Agency and will help form policy on the effects that such a treatment plant has on the environment. “This place you can be proud of it,” Ness said. “It’s cleaning the environment instead of polluting it.”