DRAINAGE PLAN DEVISED NEWHALL LAND TO TRY TO CORRAL POLLUTANTS.

Byline: Kathleen Sweeney Staff Writer

VALENCIA - The Newhall Land and Farming Company has devised a plan to limit the amount of pollutants running off urban areas and into the Santa Clara River and its tributaries.

The Drainage Water Quality Management Plan minimizes the hazardous chemicals carried to the river by urban areas with filters or wetlands to catch the contaminants before entering the river.

``It's taken on a role in our company,'' said Marlee Lauffer, Newhall Land spokeswoman. ``It's a storm-water pollution prevention plan to make sure we control runoff.''

The developer works closely with the Los Angeles Regional Water Quality Control Board, which regulates chemicals in the river and recently approved a plan to reduce the amount of chloride in the river.

The city of Santa Clarita also has asked residents to discontinue the use of diazinon, the most common pesticide used by homeowners to kill ants, because it's contaminating the river.

Under the Drainage Water Quality Management Plan, Newhall Land is working to control chemicals residents spray on their lawns or use in their yards before it reaches storm-water runoff areas.

In some areas, the company has installed filters 50 to 100 feet from the end of a storm drain and upstream from the discharge point. The filters are lined with gravel, earth or grass, and they clean up the runoff by slowing flows and allowing sediment to collect or by allowing water to percolate through the bottom of a filter before it enters the stream course.

So far, one filter has been installed on the west side of San Francisquito Creek upstream from Decoro Drive bridge. Newhall Land plans to install others around the Bouquet Canyon Road bridge.

In other places, wetlands have been built near off-channels that function similarly to a filter. Off-channels trap sediment and percolates out impurities. These systems have been constructed along the river on the north and south sides downstream from the McBean Parkway bridge.

At Valencia Bridgeport, the company installed water filtration systems in the lake, Lauffer said. Plant material was placed at the corners of the lake to catch material before it traveled down storm drains.

``The plant material helps clean out the runoff,'' she said.

So far, diazinon has not been found in the river that runs through Valencia, Lauffer added.

Newhall Land has asked the water board to approve a filtration plan near the PONY League ballfields, where Auto Row will expand.

Stephen Cain, senior environmental planner at the Regional Quality Control Board, said it has requested information about the type of pollutants the projects will add to the stream flow.

Officials will then determine whether the Drainage Water Quality Management Plan will be adequate to protect the river, Cain said. But it's not unusual to use a wetland as a water quality control measure.

``It has to be done correctly, and they have to be appropriate for the pollutant generated,'' he said. ``Every one is unique.''