SPILL'S IMPACT YET UNKNOWN; SEWAGE CLEANUP TO BE COSTLY, STUDY INDICATES.

Byline: Sonia Giordani Daily News Staff Writer

The massive spill that sent 86 million gallons of raw sewage from Thousand Oaks' main pipeline into creeks and to the ocean in February was more than a public nuisance that posed serious health hazards during its two-week duration.

It also caused costly, long-term and perhaps irreparable environmental damage, according to a 14-page report from the California Regional Water Quality Control Board detailing its reasons for slapping the city with a $2.11 million fine.

More than $1.9 million in estimated losses were reported relating to the closure of 29 miles of beaches in Ventura and Los Angeles counties.

An additional $300,000 was lost in kale, cilantro, parsley, bok choy and leaf lettuce on 68 contaminated acres of Boskovich Farms in Camarillo.

The least quantifiable damage caused by the spill, however, remains unknown as biologists study its impact on Mugu Lagoon, one of Southern California's largest and least disturbed wetlands that offers a valuable habitat for threatened and endangered species.

``The discharge of 86 million gallons of raw sewage into Arroyo Conejo flowed downstream into Mugu Lagoon, where it may have impacted important biological resources; such impacts, however, have not been fully assessed,'' the report states.

Thick mats of green algae known as enteromorpha already have blanketed pockets of the lagoon in what may be the early markings of the spill, said Tom Keeney, senior ecologist at Point Mugu.

Keeney said the algae flourishes with any increase in the amount of nutrients in the lagoon - the kind of nutrients that could have been carried by runoff from sod and strawberry farms and by raw sewage.

``We have a lot of algae here in the first place from the area farms and runoff,'' said Keeney, who said he expects the algae growth to reach its maximum level in July and August. ``But surely, the 86 million gallons of sewage didn't help.''

The California Regional Water Quality Control Board announced on Friday its recommendation to impose a $2.11 million administrative civil liability. In addition to losses related to the spill, that figure reflects a $10,000-per-day statutory fine for the city's violation of the state water code and a $21,000 charge to cover the agency's staff costs associated with research.

That sum will be considered at the agency's board meeting June 15 in Simi Valley, when the nine-member panel will discuss setting a lower or a higher fine of up to $858 million. The city has until July 15 to pay the sum, with the option of investing up to $1.6 million in local environmental projects.

In the report, state regulators outlined the facts and chronology of events that formed the basis for the alleged violations and for the fine. Among the points included in the report were the fact that the Unit W pipeline - the main line that ruptured in the Feb. 3 storm - had 10 incidents of unauthorized discharge into the creek over the past 10 years including two significant spills in August 1989 and in March 1995.

The report also notes that the city had commissioned various studies of the pipeline that showed increasing risk of rupture and that repairs ``were not implemented as planned, since funding was not available'' and alludes to the prolonged council debate over whether developer fees or resident sewer fees should have covered the cost of the sewer pipeline's repair.

City officials maintain that the fine was not warranted because the incident was an act of God, but environmentalists throughout the county are applauding the state agency's firmness.

``The regional fine seems to have been calculated based on the estimated and projected environmental damage,'' said John Busse, staff attorney with the Environmental Defense Center, a 20-year-old nonprofit environmental watchdog group.

``What remains unresolved is the blameworthiness of the City Council or staff and that's what I think will be resolved by the federal investigation,'' he said.

Under fire from both state regulators and investigators associated with a federal grand jury investigation into the sewer spill, city officials have already appropriated more than $400,000 for legal fees and staff costs related to the Feb. 3 incident.