U.S. SEEKS PAPERS ON WATER PLANT; T.O. PLANNING TO HAND OVER 13 YEARS OF WASTE DOCUMENTS.

Byline: Kevin F. Sherry Daily News Staff Writer

The U.S. Attorney's Office has subpoenaed Thousand Oaks for 13 years' worth of documents relating to problems at the Hill Canyon Waste Water Treatment Plant, where an 80-million-gallon spill was recently capped.

The subpoena demands ``any and all records, notes, memoranda, photographs and documents relating to the discharge, spilling or threatened discharge or spilling of wastewater, including untreated and partially treated sewage, from the Hill Canyon treatment plant and/or its pipelines into Conejo Creek or other waters of the state, during the period 1985 to the present.''

``It's pretty broad,'' Mayor Michael Markey said Wednesday. ``We basically intend to cooperate fully with any investigation.''

However, because the subpoena is so extensive, officials hope to meet next week with FBI investigators to try to determine the focus of the probe, said City Attorney Mark Sellers.

``It could take us two weeks of solid copying to get the stuff together'' without a better idea of what federal investigators are seeking, Sellers said. He added that the subpoena probably covers tens of thousands of documents spread among a variety of city departments.

Sellers speculated that the most recent spill - which began Feb. 3 when an El Nino-powered storm washed away two 15-foot sections of sewer pipeline - could have prompted the Environmental Protection Agency to request an investigation. The EPA licenses sewer plants and their infrastructure.

Two other major sewage spills occurred during the period covered by the subpoena: a 12-million-gallon spill in March 1995 and an 800,000-gallon spill in 1989.

Thom Mrozek, spokesman for the U.S. Attorney's Office, said he could neither confirm nor deny that a federal investigation was under way. But he did say that sewage spills are within the EPA's jurisdiction.

``The Clean Water Act regulates, among other things, the discharge of sewage into federally protected waterways,'' he said. ``There are very strict rules that the EPA places onto the operators of sewage treatment facilities.''

Should the U.S. Attorney's Office pursue a case against a city, sanctions can include administrative, civil or criminal penalties, Mrozek said. The U.S. Attorney's Office also can investigate whether there was ``wrongdoing that led to this,'' he said.

EPA spokesman David Schmidt declined to comment about the investigation.

But Schmidt did say the EPA is cooperating with the Los Angeles Regional Water Quality Control Board, which has issued a disciplinary cleanup and abatement order against the city.

The regional board also demanded an explanation for the 80-million-gallon spill, the city's plans to repair the problem and information about how the city plans to prevent future breaks.

In its response, the city said improvements to the Hill Canyon project were deferred ``due to necessary legal, planning, budgetary and financial requirements.''

``Such deferrals are commonplace with major public works projects,'' the city's response said. ``The project is currently under way.''

But getting the project approved involved a bitter political battle among Thousand Oaks City Council members. A major overhaul of the Hill Canyon plant, which included replacement of aging sewer lines, resulted in a stalemate that took years to resolve. Finally, in September, the council voted unanimously to approve the project, which is scheduled to begin this summer.