Recent tests by the state Department of Health Services at an Oxnard subdivision have confirmed the presence of petroleum-based contaminants in the soil, officials said this week.
However, the tests would not have been necessary had the department not lost portions of data from tests conducted in 1986, they said.
Jim Marxen, a department spokesman, said the loss could possibly be blamed on frequent changes in the department staff testing for toxic wastes at the Dunes subdivision, which was built in an area used as an oil field dump in the late 1950s and '60s.
Only one member of the department's staff--toxicologist Lou Levy--has been on the project for more than a year, Marxen said. In the past year, the project manager has changed three times, with a fourth project supervisor to assume the post next week.
Without the lost information, which details how the soil samples were collected and treated, results from the 1986 tests were not considered scientifically valid, said Tim Miles, who will be replaced as project manager by Pauline Bararseh.
"There was no way to tell if samples taken by us and the county of Ventura were valid," Miles said. The most recent soil samples have corrected the problem, he said.
The revelation is unlikely to boost the confidence of Dunes residents, who have complained that government officials have been slow to respond to their concerns about petroleum-based contaminants first detected in 1985 by a building contractor.
"This is a good example of why it's taken them three years to do nothing," said Paul Dolan, a leader in a lawsuit by Dunes residents against the state, the city of Oxnard, the oil companies that used the dump, several real estate agents and the company that developed the subdivision.
Marxen admitted that the loss was "sloppy." But neither he nor Miles would characterize the recent tests as superfluous.
The recent soil samples, which were collected Jan. 18 and 24, were valuable in confirming what was already known about the site, they said. The tests detected most of the same contaminants that were previously found. However, they did not find benzene, the only known carcinogen detected so far at the subdivision of about 100 lots.
Geological surveys conducted last week and in December were also consistent with past research, Miles said in advance of a community meeting Wednesday at which the department's conclusions would officially be released.
The surveys, in which scientists used radar and electromagnetic equipment to map the boundaries of the waste, found that soil contamination has been confined to an area known to have been occupied by three oil sumps, Miles said. The area covers about 20 lots or portions of lots.
The soil tests found metal, barium and several petroleum-related compounds, but preliminary research has not found any contaminants in the air or in pipes carrying water into Dunes homes.
"There's no way for this to hurt people as long as they aren't digging into it," he said.
But Dolan complained that the department issued the same assurances three years ago. "We deserve a more conclusive response," he said. "We're talking about the lives of people."
Department officials say they will pursue a full site investigation, which is expected to cost between $500,000 and $600,000 and would begin as soon as funding is available.
They said $100 million from a 1984 bond measure to clean up toxic waste statewide has been depleted, adding that they are trying to persuade legislators to earmark additional money.
However, funds set aside for administrative expenses might be used for part of the Dunes investigation, Deputy Director David Willis said Tuesday.
State health officials had expected to complete the investigation by January, 1990, but now believe that it may be delayed by "months or a year," Marxen said.
The investigation would determine whether the contaminants, which are from 1 1/2 to 8 feet below the surface in 4- to 5-inch-thick bands, have leached into ground water or vaporized into homes.
Two previous air samples have not detected vaporized contaminants at levels of concern, Miles said. In one test of 25 homes, for instance, the highest level of gas detected was at one-third of the amount that would result from lighting a gas range, he said.
Department officials plan to use more sensitive equipment in the future.
Also in an attempt to improve their investigation at the Dunes, the department plans to employ a team approach, in which the eight staff members at the site share information.
In the past, only the project manager has had an overview of the department's efforts in the area, and the project managers either have either been promoted from the Dunes post or, in Miles' case, left to travel.
"We're trying to compile the information so that there's some sense of history to the site," Marxen said. "In the past, there was no continuity."