Tollway Runoff Filtering Approaches Total Failure

Practically all the drainage filters along the San Joaquin Hills tollway are faulty and should never have been installed, according to Caltrans documents that raise new questions about tainted runoff flowing from the highway into local watersheds.

The conclusions paint a much grimmer picture than Caltrans has previously acknowledged about the effectiveness of the filters, which are supposed to block pollutants from trickling down to beaches.

Until now, Caltrans has said that only eight of the toll road’s 39 filters were faulty. But an internal review conducted last fall--after those filters were fixed--found that 35 are not operating the way they should.

The review also concluded that the filters are obsolete.

Caltrans has yet to decide how to solve the problem and estimates that a permanent solution is at least two years away.

In the meantime, Caltrans is limiting its maintenance to the detention basins that surround each of the filters and that treat runoff, saying that maintaining the filters themselves would be too expensive and impractical.

No comprehensive studies have been conducted to determine how much of the runoff from the highway is reaching local canyons and beaches.

But the revelations have sparked new concerns in cities along the tollway that are faced with the prospect that tainted runoff has been polluting watersheds since the road opened five years ago.

“This is probably the classic example of insult to injury,” said Laguna Beach Mayor Paul Freeman. “If the determination has been made that none of the filters work and none should have been installed, then to say I am frustrated would be an extreme understatement. What is going on? I don’t know. But I intend to find out.”

The toll road stretches nearly 20 miles from Newport Beach south to San Juan Capistrano, with major watersheds draining from the San Joaquin and Sheep hills toward the ocean.

The drainage system is supposed to catch and filter urban runoff--a toxic brew of rain or other water with auto waste, pesticides and animal droppings--before it flows to coastal waters.

But in a Feb. 15 letter to state water regulators, Caltrans officials stated: “Even though the [the filters] were determined to be the effective treatment devices suitable . . . during the design and construction period . . . it is now evident that they are not functioning properly and are not appropriate devices for storm water treatment at this project.”

Solution’s Vertical, Not Horizontal

The filters were designed by Stormwater Management Inc. of Portland, Ore. But the company and Caltrans said the units were built and installed by subcontractors. The Orange County Transportation Corridor Agencies oversaw the highway building project, with Caltrans and several other government agencies signing off on design and construction.

George Rudolph, director of sales for Stormwater Management, said the design used in the tollway filters was abandoned in 1998, when the company determined that gravity was working against the horizontal beds that house the filter material.

“Horizontal filters go back to the Roman Ages,” Rudolph said. “The problem with any kind of horizontal bed is eventually the sediment and pollutants collect on top of the surface. And when that happens, the water doesn’t percolate down. It eventually runs into an impervious surface itself.”

The company’s new technology basically uses the same concept but positions the beds vertically.

“At the point a storm is over, you want any of the sediments on the outside of the filter to fall away, to have a nice, fresh surface for the next storm,” he said. And that is what vertical filtration allows us to accomplish. Gravity works with us.”

Rudolph said the more advanced technology is being used with filters on the county’s other toll roads.

In a study filed Jan. 11, a team of experts assembled by Caltrans noted that the type of filter used along the toll road is no longer manufactured or sold, and that Stormwater Management recommends abandoning the current design in favor of newer technology.

In finding 35 of the filters dysfunctional, the study cataloged a variety of flaws, including:

* In some cases, water entering the filters had lower concentrations of nitrates, phosphorous and other undesirable substances than water coming out of the filters.

* The material used to filter pollutants from the runoff was washed out to varying degrees in 33 of the 39 filters.

* Excess vegetation growth caused problems for 37 filters.

* Standing water was found at 26 sites, the source of which could not be confirmed.

* Excessive sediment clogged 20 filters.

* Broken, loose or dislodged parts hampered the effectiveness of 25 filters.

* A majority of basins were designed for lower volumes of storm-water flows. And at two sites in Laguna Beach and one in Newport Beach, the filters and associated catch basins received water that was not from storms but was believed to be from natural springs.

The study does not propose a remedy. Although newer systems are being tested elsewhere in Southern California, the study said the results are too preliminary to make a recommendation.

More Study Will Point to Treatment

In a seven-page report to a state water board, Ken Nelson, interim director of Caltrans’ local district, said the agency plans systematic water quality monitoring at a few drainage sites to further investigate runoff problems. The results of the monitoring will be used to determine the extent of treatment.

Other interim measures may include decommissioning some units by removing the filtration material and rerouting the flow into detention basins. Another option would be replacing the filtration materials, costing an estimated $31,000 annually at each of the 39 sites.

Beth Beeman, spokeswoman for Caltrans’ district office in Irvine, said the state water board for the region has yet to respond to her agency’s plan of action.

“We are committed to solving this issue,” she added.

A permanent solution could be two to four years away. It could involve chemical treatment or installation of floating skimmers, oil/water separators and other devices.

The problems are only the latest for the San Joaquin Hills toll road and two other tollways built by the quasi-public Transportation Corridor Agencies despite fierce opposition from neighbors and environmentalists.

Last year, the TCA voted to spend $250,000 to install storm water runoff drains and groove the asphalt along a dreaded stretch of Santiago Canyon Road, after a series of accidents in rainy weather left two people dead and nearly two dozen injured.

And shortly after the San Joaquin Hills toll road opened, the state spent $2 million to repave a 10-mile stretch to reduce hydroplaning and skidding blamed for a rash of rain-related accidents that resulted in one death and 13 injuries.

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Faulty Flow

Caltrans has found that the drainage system designed to filter storm water runoff from the San Joaquin Hills toll road works improperly. How the system is intended to work:

Graphics reporting by BRADY MacDONALD / Los Angeles Times

Source: James Lenhart, Stormwater Management Inc.