BELLEVUE, WA, Jan. 27, 2010 -- A major sewage release last month at King County's West Point wastewater treatment plant in Seattle could have been prevented, according to findings from the Department of Ecology (Ecology), which has fined the county $24,000 over the incident.
The 8.7-million-gallon release of untreated sewage began at 10:02 p.m. Dec. 14, 2009, and lasted 2 hours and 52 minutes. An electrical short circuit in a no-longer-used system, coupled with operator error, caused an emergency bypass gate to open, diverting a portion of the incoming wastewater around the treatment system and into Puget Sound off West Point. The release had originally been estimated at 10 million gallons.
Ecology investigators determined that after the electrical malfunction occurred, operators failed to implement the facility's standard operating procedures, and did not use a backup system that can override the controls and close the gate within minutes.
Workers summoned a technician who diagnosed and repaired the electrical problems. The gate was shut at 12:54 a.m. on Dec. 15.
A King County Wastewater Treatment Division internal investigation into the incident continues.
"King County has taken this incident very seriously, but significant errors led to the spill and made what could have been a small release much larger," said Ecology's Water Quality Section Manager, Kevin Fitzpatrick. "The backup system was tested and ready, but inexplicably not used during the very time for which it is designed."
Ecology's penalty cites the county for three violations:
1. Discharge of pollution matter into state waters, a violation of the state's Clean Water Act.
2. Failure to minimize the discharge, as required in the plant's water quality permit, by not employing the backup system to close the gate.
3. Failure to properly operate and maintain the plant, as required in the permit.
The bypass gate is part of an emergency system designed to protect the treatment system during major power outages and from extremely high flows from heavy storms. The system usually is off, but is placed into a "standby" mode when incoming flows reach a critical threshold. The unexpected gate opening occurred when operators switched the system to standby mode.
"The county's Wastewater Treatment Division takes full responsibility for the overflow, which was unacceptable given the environmental mission of our agency," said King County Wastewater Treatment Division Director Christie True. "We've implemented a number of corrective actions including retraining all operators and reassigning staff, and the County Executive has directed us to review the chain of events that led to this overflow and continue making efforts to improve our standard operating procedures."
King County may request a review of the penalty by Ecology or may appeal directly to the Washington State Pollution Control Hearings Board within 30 days. Proceeds from water quality penalties enter Ecology's Coastal Protection Fund, which awards grants for local, state and tribal government habitat improvement projects.
Water quality permit enforcement is part of Ecology's ongoing efforts to meet the state's goal of restoring Puget Sound by 2020 and to protect citizens and the environment from toxic threats.