City officials in Vacaville, Calif., confirmed Friday that sewage has been entering the local storm drain system due to an incorrect connection at a local construction site.

While an exact timeframe has not been established, some officials estimate that sewage has been entering Vacaville's system from temporary facilities on the Kaiser Medical Center construction site for up to two years. The 50-acre project site is located south of Vaca Valley Parkway near Leisure Town Road.

"Due to a mislabeling of the sewer and storm drainage lines, the Vacaville Medical Center construction trailer sewer lines were inadvertently hooked up to the storm drain lines," said Jim Caroompas, a Kaiser spokesman. "When we became aware of the situation earlier this week, we immediately took steps to correct the problem, which was completed in less than 24 hours."

The situation, which was discovered Thursday, was due to a cross-connection, said Vacaville Chief Building Official Jay Salazar. "It was clear that it was an honest mistake," he said, describing the lines as closer together that usual and the same color and size. "I understand, from my own perspective, how it could not be detected at the time of inspection."

The proximity of the storm drain and sewer lines, on top of other circumstances, made for a "perfect storm," according to Salazar. Occupants at the site were ordered to leave while the cross-connection was fixed and city crews tested their repairs; Salazar praised the project contractor, Rudolph and Sletten, for its quick action.

"The contractor was very cooperative in handling this and notified the city immediately," he said. "It was probably the best way it could have been handled given the seriousness of the situation."

The storm drain flow, according to Senior Civil Engineer Steve Sawyer, crosses through a culvert under I-80 and makes its way to Horse Creek. "The city and state are taking samplings downstream and trying to determine the extent of the contamination that occurred and how much environmental cleanup will be required," he said.

City-employed environmental compliance inspectors are trained to investigate these types of incidents, according to City Quality Manager Jacque McCall. "We consider this an illicit dicharge," she said, adding that the Central Valley Regional Water Quality Control Board has the ability to levy fines of up to $25,000 per day.

More than 300 outfalls exist through which storm drain flow empties into the creek, according to public works staff. All have been inspected within the past 18 months without any debris being found, officials said. The situation was likely mitigated by a filter placed in the Kaiser site's storm drain system.

"This is most fortunate and a good use of storm water pollution control technology," McCall said. "Any debris in the storm drain, behind the treatment unit, will be removed by the environmental contractor."

Source: The Reporter