Inflow and infiltration cause city plant to exceed limits

SANDPOINT — After reviewing nearly four years of data, the Environmental Protection Agency notified Sandpoint that its wastewater treatment plant has been in violation of the Clean Water Act on multiple occasions since November 2001.

Many of the violations were self-reported and involve the plant exceeding federal effluent limitations of E. coli, chlorine, biological oxygen demand and total suspended solids.

Sandpoint Public Works Director Kody Van Dyk said the culprit for the violations has been an excess of groundwater inflow and infiltration into the city’s sewer system.

Cracked sewer pipes, faulty manhole covers and residential drainage problems have led to an influx of ground and stormwater entering wastewater sewers, which, after a heavy storm or melt, can overwhelm the treatment plant to the point where it exceeds limitations on pollutants.

Van Dyk said that while Sandpoint officials take the violations seriously and plans to step up its plans to deal with inflow and infiltration problems, he does not think residents should be worried about water quality.

“People shouldn’t be concerned. These are not extreme water quality violations,” Van Dyk said.

Inflow and infiltration is also being blamed for violations that took place on Jan. 1 and Jan. 10, 2006, when sewage backed up into private, residential basements.

Any incident that endangers human health or the environment needs to reported to the EPA within 24 hours to avoid being in violation of the city’s national pollutant discharge elimination system permit.

Van Dyk said the city was unaware the incidents constituted violations, but said he will change the reporting system to come into compliance with the rules.

The EPA is currently reviewing the violations for possible further enforcement, which could include penalties of up to $32,500 per day, per violation.

Van Dyk said there is a very good chance the city can avoid fines if it works in concert with the EPA on ways to minimize the problems associated with inflow and infiltration.

To counteract the inflow and infiltration, the city will dedicate $3.5 million of an $8.75 million sewer improvement bond for repairs on city-owned sewer pipes.

Van Dyk said he will also push for a city ordinance that requires individuals to properly maintain their private sewer lines, which he said causes the vast majority of inflow and infiltration.