Stormwater sidetracks sewer system?
Sue Hanson/BSAC Chairman
Most folks think of snow melt and rain as pure and much needed moisture. It is. What happens when snow melt or rain water makes its way downhill to the nearest river or lake can create unintended problems. Rain is like a shower or bath for all things outdoors. All the dirt, grime, grease, oil and waste that is on our buildings, in our yards, on the streets, driveways and parking lots gets washed away down a storm drain or stormwater conveyance and eventually reaches Flathead Lake.
When water makes its way through fields, lawns, dirt roads, borrow ditches and the forest floor it picks up passengers. Fertilizer, pesticides, sediment, animal droppings, dead leaves and nutrients (or pollution) from failing septic systems are frequent passengers. Engine oil, roofing materials, brake and clutch fluids, gasoline, antifreeze, and pet droppings mingle with stormwater on the way to water bodies.
Sewer systems were never intended to deal with stormwater. The stormwater system in the Bigfork area is antiquated and totally independent of the sewer system. In the village area, stormwater is discharged, untreated, directly into Bigfork Bay.
Sewer systems are designed to treat household waste from businesses, kitchens and bathrooms. Treatment includes organic bio-membranes to break down waste. When pollutants such as oil (hydrocarbons), sediment, metals and household hazardous waste enter the treatment facility the organic material is diminished or destroyed and cannot breakdown waste. That means a reduction in effectiveness or rendering the treatment protocol ineffective. The result is that treated wastewater may, in fact, leave the facility untreated to minimum standards and outflow into the lake in that state.
Homeowners who use sump pumps in high groundwater areas often believe it is a good idea to discharge into the sewer system. Unwittingly, they are introducing harmful pollutants into the treatment facility. Winter weather frequently jams up the manhole covers of the sewer collection system with ice, and the melt thereof allows the collected backlog of street melt to infiltrate the manhole covers.
Occasionally, in an unusually high water event from fast melting snow or heavy rain, stormwater travels along sewer lines and infiltrates the mains, manholes or service lines that are not pressurized. Such an event took place in 2006. An unprecedented surge of storm water entering the sewer system through these as well as unsecured new sewer mains that were under construction caused the sewer plant in Bigfork to discharge a small amount of untreated water into the lake. District operators were able to minimize the discharge by working around the clock manually operating lift stations to allow the sewer plant to keep up with the flow of excess storm water.
The Bigfork Stormwater Advisory Committee (BSAC) will be conducting educational workshops on stormwater issues in the near future. It is important that the community be a part of the process. There are many ways individuals can participate in the mitigation of stormwater pollution. Take a look around your home or business with an eye for "where does the water go?" The following are suggestions for what individuals can do to reduce pollutants.
? Don't apply fertilizers, pesticides, or herbicides near a water body, stormwater conveyance or flush into sewer lines.
? Direct runoff from hard surfaces like driveways, concrete patios and rooftops away from stormwater and sewer conveyances. Water the lawn or provide a depression or pond to permit gradual infiltration.
? Never dump motor oil, grass clippings, leaves, animal waste or other pollutants into road gutters, storm drains or sewer drains.
? Dispose of paints, thinners and other solvents at a household hazardous waste collection facility.
The next Bigfork Stormwater Advisory Committee meeting is June 24, 2008, 5:00 p.m. at the Saddlehorn Discovery Center on Grand Avenue in Bigfork. All are welcome to attend the meeting and become part of the solution.