The Orange County Grand Jury is urging Huntington Beach officials to put pressure on the state to finish cleaning up an old landfill site and study whether there is a connection between health issues reported by some residents and the toxic waste.

Grand Jury members wrote in a report released June 20 the state’s effort to clean up the ASCON landfill site in south Huntington Beach has been “agonizingly slow” and they are calling for city officials to get involved.

“The plans for reclamation and the clean-up of this site have been in the works for many years, certainly for more years than anyone would have thought possible,” the report says. “The time involved in getting this notorious site cleaned up may very well seem excessive to many.”

The 38-acre ASCON site near Magnolia and Hamilton avenues is made up of five visible waste ponds that have been described by some as the city’s own tar pits because of the black sludge that fills the pools.

There are also eight pits filled with industrial waste, and all but one have been buried over the years, according to the ASCON project website.

As of July 2011, Cannery Hamilton Properties, which includes Chevron and Conoco Phillips, owned the property and was expected to put up between $46 million and $81 million to clean the site.

The first stage of the cleanup was completed in the spring of 2011, but further reports and studies need to be complete before the rest of the effort can get under way, according to the California Department of Toxic Substances Control (DTSC).

State officials have previously said they anticipate the site will be fully cleaned by 2015.

The Grand Jury first looked at the site more than a decade ago and determined then that it posed “potential danger to the health and safety of the community,” the report says.

The site was first labeled hazardous by the state in 1991.

In 1992, another cleanup started and the land was slated for 600 homes, but developers said construction could not begin until at least 1995, the Grand Jury’s report says.

Over the years, cleanup efforts were stalled because the site changed ownership several times and years of studies were needed to assess how to handle removal of the hazardous materials.

The Grand Jury report says an order was issued in 2003 that demanded cleanup of the site.

DTSC announced its remediation plan in October 2009. Officials said there were no immediate health risks to the community, but allowing the tarry sludge to sit could have long-term impacts.

Cleanup efforts were launched in 2010.

In July 2010, officials estimated there was about 100,000 tons of tarry material slated to be removed from the landfill. About 96,000 tons have been taken out so far, according to DTSC project manager Safouh Sayed.

The potential health risks of living near a toxic waste landfill have weighed heavy on some residents for several years.

The landfill functioned as a waste disposal facility from 1938 to 1984, serving as a dumping spot for oil field debris in its early years and after 1971, for abandoned vehicles and construction materials such as concrete, metal and wood.

Arsenic, sulfuric acid and benzene acid were among the toxins detected in the pits, and if left alone, there was a possibility the ground water supply could eventually be contaminated, officials reported.

So far, there has been no distinct link found between ASCON and any health risks, but the Grand Jury wants further study, according to their report.

An unnamed USC medical school professor quoted in the Grand Jury’s investigation said she is concerned about the number of brain stem cancer incidents in children in south Huntington Beach, but the evidence does not clearly point to ASCON as the cause.

“Clearly, statistical reports have not quieted fear of some residents show continue to believe there is a link between health issues and the dumpsite,” the report says. “Several neighbors have kept track of ‘numbers of people’ with neurological disorders.”

The city will have 90 days to respond to the Grand Jury’s report in Superior Court.

More to come.

Contact the writer: 714-796-7953 or jfletcher@ocregister.com