Oceanside On June 11, the local division of the state water board ordered the North County Transit District, which recently completed the Sprinter rail project, to pay a $685,000 fine for discharges of construction sediment into waterways, including southern Oceanside’s Loma Alta Creek.
The discharges are just the latest incidents in the creek’s murky history, which, according to the Loma Alta Creek Watershed Management Plan, includes a decade’s worth of pollution caused by residential and commercial development.
Loma Alta Creek runs parallel to Oceanside Boulevard, starting approximately seven miles east of the creek’s outlet at Buccaneer Beach. The creek is a natural drainage course, fed by storm drains and hillside seepage from over 6400 acres of land, 70 percent of which is deemed urbanized. During its journey to the coast, the algae-covered flow picks up high concentrations of chlorides, sulfides, oil, grease, and coliform bacteria — from human, bird, and pet fecal waste — earning the creek a spot on the federal Clean Water Act list of impaired water bodies.
The creek empties into the Loma Alta Slough, located across Pacific Street from Buccaneer Beach. A man-made sandbar prevents the bacteria-laden water from flowing onto the beach and into the ocean, but during heavy flows, the water breaches the sandbar, causing closures at the popular beach.
Buccaneer Beach, as well as the 1.1 miles of coastline surrounding it, also has a spot on the federal Clean Water Act list of impaired water bodies.
In 1992, in response to frequent closures of Buccaneer Beach, the City of Oceanside installed a pipe in the slough. The pipe hooked up with the outflow pipe from the La Salina Wastewater Treatment Plant, just to the north. The combination of treated sewage and untreated water from Loma Alta Creek was released 1.6 miles out into the ocean. Nearly one million gallons of untreated water was discharged per day.
Guss Pennell, environmental compliance officer for Oceanside, recalls the decision to divert the water. “The City of Oceanside made the decision to try and clean this beach up. Kids would typically play in the water from the creek because it was warmer and there weren’t any waves. I used to walk the beach back then and take samples, and I’d have to advise the parents to not let their kids play there. They would run over to the showers and start washing their kids off.
“We started thinking about diversion, and that’s when we diverted the water to the outflow pipe for the sewage plant. For us, at the time, we considered it to be an ideal solution. It’s 1.6 miles out, and anything bad in the water gets diluted,” says Pennell. “But because of the city growing like it has, we started getting closer to reaching the capacity for the outflow pipe. Plus, the Regional Water Quality Control Board didn’t like the fact that we were discharging untreated water into the ocean.”
In 2006 the City of Oceanside approached the State Water Resources Control Board for financial help in solving the problem at Buccaneer Beach. The solution, a $5 million ultraviolet-light treatment facility, is designed to capture the water and zap it with high-frequency electromagnetic radiation before sending it through a newly installed pipe onto the beach.
Pennell explains the process. “The water goes into a pipe, which is connected to a wet well. The wet well is actually deeper than the slough, and it’s got pumps in it. So when the slough fills up, the water just flows through the pipe and into the wet well. A pump then sends it through a two-millimeter filter. After that, it is sent to a sand filter, which is constantly cleaning itself. The debris gets bubbled up and flows into the sewer line.”
Two 16-foot-tall sand filters, half hidden in a concrete trench located just outside the treatment plant, provide the final filtering process before the water streams through ten-inch pipes into the boxy cinder-block plant to get zapped by the two-and-a-half-foot-long lamps.
“There’s a tube that the water goes through,” Pennell says, “and the ultraviolet lights are inside sleeves, and the water passes around them while the light is radiating. The light is enough to kill all the bacteria. As the bacteria pass, they just get zapped. But the water needs to be clear. If you have dirty water or it has chunks, the light can’t go through it.
“The process has been used for quite some time for drinking water,” adds Pennell.
The facility, located at the southwest corner of the La Salina Wastewater Treatment Plant, is designed to filter up to 700 gallons per minute, more than adequate during meager dry summer flows, which average approximately 300 gallons per minute. However, anything over the maximum will require the City to shut down the plant.
The plant will be operational only in summer months. In the winter, the outflow from the Loma Alta Creek and slough can be far too much for the facility to handle. “During winter, after heavy rains, it’s like a river here,” says Pennell, “and you would have probably 5000 gallons per minute going through here.”
Not only does the ultraviolet light facility not treat water in winter months but the source of the bacteria has not been addressed. “We’ve just hired two guys to inspect every industry in the city, in hopes to curb the issue of runoff, and we monitor the storm drains every year,” says Pennell. “But if you look along the creek, these pipes coming from neighborhoods flow 24/7, because people are overwatering their lawns and washing their cars.”
Chiara Clemente is a senior environmental specialist for the Regional Water Quality Control Board. “More detection or micro-scale removal has to happen,” she says. “In other words, they’re just treating it at the mouth. One way to approach it would be to go up into the regions and try to have more detention bases where pollutant removal would occur. They would be like little ponds and would capture the water, allowing the bacteria to attenuate. It would clean up the water upstream, and it would clean up more than just the bacteria. The more micro-scale you go, the better.