Fun with numbers

On a sunny Wednesday in March, two Metropolitan Wastewater Department supervisors are tracking their crews using GPS and a sophisticated database running on a nearly indestructible Panasonic Toughbook.

Driving through Mission Hills as Lady Gaga’s “Bad Romance” plays on the van’s stereo, they locate a “television” crew running a camera down a sewer main. They’re looking for grease and root blockages, the main causes of sewage spills.

“Twenty years of dirty movies,” veteran wastewater technician Brian Dantzler says. “I make the dirtiest movies in San Diego. Triple-X.”

In the Crown Point area of Pacific Beach, another technician feeds a “Piranha” hose with a high-pressure “Bulldog” nozzle down an easement. His partner maneuvers through thorny bushes and weeds to uncover a lost manhole where he’ll check what’s washing through.

Meanwhile, on a hill overlooking the airport, a “rodding” crew is rushing to avert a spill. A section of a ring-shaped root saw broke off in a stretch of sewer buried 18 feet deep in the ground. If the workers can’t fish it out within an hour, sewage will back up through the manhole. The supervisors joke that they’ll all receive pink slips if they cause a catastrophe while taking a reporter on a tour.

At the nadir of a steep hill, a supervisor reflects light into the bottom of the sewer with a small mirror, while a technician drops a grappling hook into the manhole. His partner, barely visible at the top of the street, jams a long rod with a spiral tip down the 6-inch-wide sewer. After about a half-hour, they snag the rusted metal, avoiding a Code 735, which is when a spill is leaking into public waters.

This system’s effectiveness led Mayor Jerry Sanders last month to commend the city Wastewater Department for a steady drop from 84 spills in 2006 to 38 in 2009, a more than 50-percent improvement.

“Most of you know sewer spills used to be a huge problem in this city,” he said to reporters. “Since 2006, we’ve seen the number drop by more than half. What this means for our city should go without saying. It means cleaner rivers, lakes, oceans and beaches.”

But Sanders was only counting spills that occurred in city-owned sewers. He did not take into account the volume of the spills, nor did he count spills on private property. Without that data, it’s difficult to say whether public waters are, indeed, cleaner now than in 2006—especially since instances of sewage reaching public water and sewage-related beach closures have remained relatively constant.   

The city reports sewage spills to several state agencies, which in turn calculate spills in their own ways, some of which contradict Sanders’ claim.

The California Integrated Water Quality System’s database (CIWQS) shows:

• 61 public-property spills unleashed 168,840 gallons in 2006, steadily decreasing to 21 public-property spills that leaked 77,257 gallons in 2009. That’s a 65-percent improvement and much better than Sanders’ data. The city also saw a steep decline in sewage spills making it to public water. However, the database does not include a 380,000-gallon spill at Lake Hodges, although the city of San Diego was fined for the spill in November.

• Comparing 2006 with 2009, the number of private-property spills decreased from 73 to 32, but the volume increased from 15,515 gallons to 16,358 gallons.

These numbers seem incomplete compared with another database of hazardous-material incidents kept by the California Emergency Management Agency. This database doesn’t differentiate between spills by the city and private spills that occur in the city. CityBeat’s data analysis showed:

• The total number of sewage spills decreased 32 percent from 180 spills in 2006 to 123 spills in 2009.

• The total volume of the spills, however, has not waned. In 2006, 178,364 gallons leaked from public and private sewage lines and remained level in 2007, excluding the Lake Hodges spill. The volume declined slightly in 2008, but then it doubled in 2009 to 373,202 gallons.

The reason for the climb: Costco, off Interstate 5, between Clairemont and La Jolla.

During eight days in May, the megastore leaked sewage at a rate of 25 gallons per minute into Rose Creek. An “interceptor”—machinery that channels spills back into the sewer system—kept the 259,475 gallons of sewage from contaminating Mission Bay.

 “Had there not been an interceptor system, this would’ve been a disaster,” says Stanley Griffith, deputy director of the Wastewater Department.

The city billed Costco $5,638 for cleanup, which included “vactoring,” or sucking up, 13,312 gallons that didn’t make it into the interceptor.

According to records from CIWQS, Campland on the Bay RV park and De Anza Point were affected. Employees at Gym Ventures, a gymnastics studio for children above Rose Creek, claimed they could smell it. Yet, by and large, the community—including the environmentalist group Friends of Rose Creek—had no idea that the largest spill of the year occurred in their backyard until contacted by CityBeat.

It’s unclear what the impact on the ecosystem was, but based on the data collected by six teams of students at Mission Bay High School in February and March, Rose Creek seems healthy.

However, the results—which will be presented at the San Diego Science Festival at Petco Park on March 27—also show that bacteria from fecal matter was present in Rose Creek.

“The tests were definitely all positive,” says Kady Bixby, the freshman who conducted the coliform tests. “It means there was bacteria…. There are different pipes that flow into [Rose Creek], as well as the bay, so we believe that the bacteria came from animal feces or sewage.”

The bacteria could be a natural product of the habitat, or it could derive from the spill. Bixby says more tests are required to determine whether that bacteria comes from humans.  

The environmental watchdog organization San Diego Coastkeeper finds the drop in Wastewater Department spills encouraging, but it’s only a sliver of the problem when you look at sewage spills in the aggregate. The city, as opposed to the city government, needs to act.

“That’s something we have control over,” Coastkeeper legal director Gabriel Solmer says. “As residents, we cannot be putting grease down our drains.”

Coastkeeper is also irked about another item Sanders omitted from his speech: San Diego’s improving as a result of a lawsuit filed by Coastkeeper and Surfrider Foundation following a 34-million-gallon spill into Alvarado Creek in 2000.

The city paid a $3.5-million fine for the spill, but that’s not always the case. The San Diego Regional Water Quality Control Board has no plans to fine Costco, says Jeremy Haas, the board’s senior environmental scientist.

Costco did not return CityBeat’s inquiries about how the spill happened and what measures it has put in place to prevent future spills.

“What we want to change is the culture of ‘fix on failure,’” Solmer says. “The responsible party needs to face a penalty as an incentive for it not to happen again.”   

Write to davem@sdcitybeat.com and editor@sdcitybeat.com