Sewage overflow in torrential rains lead to oyster closure
Heavy rains last week led to around 40,000 gallons of
raw sewage spilling into Semiahmoo Bay from the Blaine
Public works director Steve Banham told city council at their January 24 meeting that 4.9 inches of rain fell in Blaine on January 17, coming on the heels of an already rainy weekend. Crews had already deployed temporary storage bladders next to the old storage tank on Marine Drive. “We filled the bladders and the tank, then we emptied them when we could, but then on the 17th it was just too much,” Banham said. For 40 minutes overflowing wastewater ran into the bay.
“The unfortunate part of it was it happened on an incoming tide,” Banham said. “The concern there was that some of what we spilled came into the harbor on the tide.” That led the department of health to close shellfish harvest in the harbor until the end of the month, which meant the community oyster farm had to wait two weeks to pick up baskets of already picked oysters waiting out on the mud flats.
“With the combination of rain and sewage we’ve lost half a month,” lamented oyster farm program manager Geoff Menzies. Menzies said the volunteer oyster farmers go out on nighttime low tides every other week and three $800 loads of jumbo oysters, two which they process and ship to their buyer in China and one they hold for the following week. However, the department of health has put a conditional approval on shellfish harvest in the harbor, which had been closed to harvest due to fecal coliform pollution for a decade. They found that fecal coliform levels in the harbor were safe in dry weather but went up when it rained, so every time a half-inch or more of rain falls, shellfish harvest is shut down for five days. “We had big plans for January until those big rains,” Menzies said. “Then what killed the month was the overflow.” He said the farm had through June to harvest the crop remaining in the harbor, the proceeds of which will be used to improve water quality.
Banham said engineers were starting work this week on a project destined to eliminate overflows even in torrential rains – a 700,000 gallon tank under Marine Drive to hold wastewater in excess of the system capacity. The current temporary bladders and old tank hold 260,000. “It almost triples our capacity which get us out of sleepless nights,” he said.
A new $18 million sewer treatment plant on Marine Drive, planned to start operating in August of 2008 according to the completed facility plan presented to city council January 24, will also double the city’s capacity for treating wastewater.
Banham said they are continuing monitoring to reduce infiltration of stormwater into the system. Banham said the facility plan is being submitted to the state department of ecology for review and with their approval design of the new plant can begin.