16 Jan Spokane builds Storage Tanks to Offset Wet Weather Overflows
The winter months in Seattle, Spokane, and other nearby cities, bring challenges for street maintenance and storm water systems due to the inclement weather. The water systems have been cause for concern, as bouts of snow have piled up in neighborhoods throughout the state. Once melting begins as the weather turns moderate to mild, this can signal a source for sewer system overflows. Additionally, the recent overnight lows just above freezing, coupled with rain, has created an undesirable effect on the water systems. With an estimate of 10 inches of snow piling up over the past several weeks, stormwater pipes and the massive underground tanks which are to be installed to store combined sewage, have become decidedly necessary. The tanks will bring the underground capacity to over 14 million gallons before runoff tips the limit, overflowing unsorted sewage into the river. The objective is to lessen the frequency of the sewer overflows, while not eliminating them completely. The tanks are designed to bring the city in line with a decree to limit the untreated water- flowing into the river at 20 sites- to once per year. It’s estimated that over the past five years, the average amount of untreated water that has entered the river as a result of system overflows has been approximately 52 million gallons. The tank, while under construction, is operational and is in the process of being calibrated to collect stormwater. The city will have the ability to drain a portion of the water in the tank if levels are approaching overflow.
Interestingly, in order to ensure the melting snow gets in the system, not in the ponds or streets, residents are asked to clear drains around their home in order to prevent an overloaded system. In the event of warmer temperatures and rainfall, melting will be accelerated. The city of Spokane, in particular, is advising that such conditions will likely move into neighborhoods before the end of the month, though river flooding is not expected.