Arroyo water quality considered safe
By Darleen Principe darleen@theacorn.com

Although the water flowing through Simi's wash is high in salts, experts say, it's safe for recreation.

The Los Angeles Regional Water Quality Control Board, which monitors water quality in Calleguas Creek, identified pesticides, sediment, ammonia and chlorides- or salts- as the main pollutants in that reach of the river known as the Arroyo Simi.

Steve Cain, spokesperson for the water quality control board, said the agency is currently trying to determine the actual level of chlorides in the water in order to adopt the proper regulations to begin cleanup.

Regulations have already been adopted within the last year to address the other three pollutants, he said.

"We're actively involved in returning water quality to the arroyo," Cain said. "Investigations are continuing in that creek to see if there are any other pollutants."

Ready to revitalize

Last month, the Arroyo Simi Ad Hoc Committee- a collective of representatives from the City Council, the Simi Valley Unified School District and the Rancho Simi Recreation and Park District- presented a study to the public detailing the envisioned transformation of the Arroyo Simi into a greenway.

The idea is to revamp the 12mile corridor, which begins at the east end of Simi at Corriganville Park, to make it more suitable for recreational use and habitat preservation.

The concept has raised questions about whether the water in the arroyo would be safe enough for a greenway.

Don Kendall, general manager at Calleguas Municipal Water District, said most of the water flowing through the arroyo comes from several dewatering wells, mostly on the east side of the city, that pump excess groundwater.

Everything from agricultural and urban runoff to natural erosion and other processes may ultimately dictate which pollutants end up in the corridor.

"It's not necessarily a bad thing," Kendall said. "It's helping to recharge the aquifer system. From the Calleguas perspective, our interest is to keep the water flowing in the arroyo- to let it be a natural waterway."

M. Ali Tabidian, a hyrdrogeology professor at Cal State Northridge, said the Calleguas dewatering project currently has a Total Dissolved Solids measurement- the standard for describing water quality- of about 2,000 mg per liter while the federal Environmental Protection Agency recommends a TDS measurement of 500 mg per liter for drinking water.

Still, the pollutants identified by the Regional Water Quality Control Board are not unusual and as long as the water currently going through the arroyo isn't used for drinking, it shouldn't have any impact on recreational activities, he said.

"I think this is a very good idea," Tabidian said. "You can go to many parts of the world and see countries that have done an excellent job of utilizing river banks for these types of activities."

Where the water goes

According to Tabidian, the excess groundwater pumped through the dewatering wells is dumped into the arroyo at an average of 2,000 gallons per minute.

Kendall said the water ultimately flows through the city and into the Simi Valley Wastewater Treatment Plant, where it is mixed in with about 10 million gallons of treated water each day.

Some of the water continues to flow through Conejo Creek, while much of it is used for irrigation in the Tierra Rejada Valley greenbelt, he said.

"The water is primarily pumped by agriculture, where it again percolates to groundwater," Kendall said.

"Agriculture is primarily the affected party because of the increasing chlorides as urbanization has occurred. But on the other side, it's been a good thing because it keeps water in the arroyo," he added.

Cain said the greenbelt serves as a natural filter and actually improves the water quality in that area.

Rocketdyne runoff

When asked whether contamination from the former Santa Susana Field Laboratory poses a threat to the water quality, Kendall said there is a monitoring system in place to make sure it doesn't pollute the Arroyo.

"We have seen no evidence of any (SSFL pollution), but we're very interested in the cleanup activities at that site," Kendall said. "We see nothing. It's so far away and we don't anticipate seeing anything."

Ongoing maintenance of the Arroyo Simi and the development of an integrated watershed management plan could qualify the waterway for funding by California Proposition 84, which allows the state to sell bonds in order to fund programs to maintain water quality, flood control and natural resource protection.

The approximately $215 million of Proposition 84 funds earmarked for the region that includes Los Angeles and Ventura County, is seen by Calleguas and the Arroyo Simi Ad Hoc Committee as a potential funding source for the greenway project