No More Overflows

I&I control, effective root treatment and FOG regulations help a California water and sewer district say so long to SSOs

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Roots, inflow and infiltration (I&I) and calcium deposits had caused major backups for the El Toro Water District in Lake Forest, Calif.

 

The district, eight miles from the Pacific Ocean and surrounded by San Diego Creek to the north and Aliso Creek to the south, straddles the dividing line between the State Water Resources Control Board Regions 8 and 9. Sanitary sewer overflows (SSOs) into these waterways arrive on Orange County’s million-dollar beaches.

 

By creating aggressive I&I and root-control programs, establishing FOG permits, and going above and beyond the norm, the district has eliminated potential SSOs. The district won the Santa Ana River Basin Section 1995, 1998, and 2000 Collections System of the Year awards from the California Water Environmental Association.

 

Hills of gold

The 8.5-square-mile El Toro district covers the cities of Lake Forest, Laguna Hills, Aliso, Viejo, Laguna Woods and Mission Viejo. The laterals and 142 miles of 4- to 24-inch gravity mains are 99 percent vitrified clay pipe almost 50 years old.

 

“We had one or more stoppages every six months in the late 1980s and early 1990s,” says Ralph Palomares, collection system supervisor. “Our lines had cracks, offsets, root intrusion, and FOG, which we discovered in 1988. We were well ahead of the game by the time the 2004 Water Discharge Requirements mandated inspection of the entire collection system.”

 

It took the two-man camera crew five years to complete the first inspection, and the district is halfway through the second. Of the 537 identified repairs, 350 were completed as of mid-April. That leaves the most challenging portions — the 6 percent running between condominium complexes and homes on hillsides where no inspection vehicles can go.

 

To solve the accessibility problem, the district is considering a pushrod easement camera system. For mainline inspections, the district has custom-built Grumman and Ford cargo vans outfitted by Pearpoint. Since crews never know how long they will be in the field, the Grumman unit, which also serves as an incident command center in the event of earthquakes, has microwave ovens, a TV set and a refrigerator.

 

The first complete inspection revealed two major problems, roots and calcium deposits. The latter surprised everyone because the 1-inch jetter hoses passed through the 6- to 8-inch pipes without snagging. Maintenance crews open-cut and replaced occluded sections with ABS USA plastic pipe, finding it faster than removing the calcium. “Chain cutters work, but take two days to advance 12 inches,” says Palomares. “The material is so hard that sparks fly when you cut it.”

 

Protecting customers

Homes in residential areas have large front yards and a tree park between the sidewalk and street. The trees don’t belong to the district, but the laterals from the main to three feet beyond the sidewalk do. When roots are an issue, crews open-cut and replace laterals with a seamless length of ABS pipe, then wrap the joints or pour slurry around them to keep out roots.

 

“If we see roots in the lateral and the property has a cleanout, we’ll insert the push camera to identify the source of the problem,” says Palomares. “Ninety-nine percent of the time, it’s in our section of the pipe.” After removing the roots with a cutter from Spartan Tool, the lateral is inspected again and the data stored on flexidata survey software from PipeLogix Inc.

 

While other districts clean only the mains, El Toro aims to help residents. If crews identify roots collecting grease and disposable wipes in homeowners’ laterals, they cut and jet from the cleanout to the main, then inspect the line for about $75. “If there is no cleanout, we advise residents to call a plumber,” says Palomares. “We’re at the inspection to see who is responsible for the problem. If we are, we’ll repair it as soon as possible, or let the homeowner hire a plumber.”

 

The district’s customer care policy even protects them from occasional unscrupulous plumbers. Newsletters, mailed with water bills, advise homeowners to call the main office if they have a sewer problem. An employee evaluates the situation and advises whether to call a plumber.

 

“If we can fix the problem, we’ll do it right away, and customers always want to pay our price,” says Palomares. “We’re happy because we know the problem is fixed correctly. We’ve gone back the next day after a plumber allegedly cleaned the line and have seen sewage spilling from the cleanout. The guy never came, or he tapped a hole in the lateral with his bullet cutter and left.”

 

Foam and hats

Cutting the roots is just the first step in controlling them. Crews return 30 to 40 days later to treat the laterals with RootX chemical formulation, which uses the aquatic herbicide dichlobenil. They foam six 350-foot segments manhole to manhole, or fifteen 100-foot-long, 4- to 6-inch laterals per day. “The biggest mistake people make is foaming immediately after cutting the roots,” says Palomares. “Roots don’t absorb nutrients while they’re bleeding, so treating the same day is a waste of money.”

 

In the district’s root maintenance program, line inspection comes first. If finger roots are present, crews give them a light foaming to avoid wasting product.

 

“We’ve used RootX for 14 years, and it keeps the roots at bay,” says Palomares. “Our major problem now is reaching the lines in hard-to-access areas to repair them. I see foaming decreasing in probably seven years as our point repair program reaches its conclusion.”

 

The district repairs most mains by open-cutting and dropping in sections of ABS pipe, but a fiberglass point repair process called Top Hat from AMerik Engineering will allow the district to do more with its money when only small sections of pipe are bad. After five demonstrations and assurances from another agency using the product, Palomares is confident it will work. The resin-impregnated fiberglass system cures in place with ultraviolet light.

 

The second sewer inspection revealed prime slip-lining candidates. One, a 10-inch trunk line half a mile long, had roots hanging like curtains from every 6-foot section joint. “It’s on the property line between two malls, and the developer planted trees along the top of the line,” says Palomares. “We can’t open-cut without cutting down the trees, but cutting the roots and slip-lining is possible.”

 

Grease gremlins

The district also has 120 high-maintenance areas that are cleaned every two weeks or monthly on a staggered schedule using two sewer cleaners from Vactor Manufacturing, and two truck-mounted jetters and an easement machine from Sewer Equipment Co. of America. The clogging agent is often grease.

 

Since 1990, the district has inspected all 200 restaurants in the area as part of its FOG program. Shopping centers with numerous restaurants had the most SSOs, so the Orange County Health Department introduced rules and permits in 1998 to reduce them.

 

“Back then, most eateries had 6,000-gallon grease interceptors,” says Palomares. “They were odor-causing machines because they became septic, producing hydrogen sulfide at levels right off the gas meter charts. Too many cities still specify only 3,000-gallon interceptors. Three months later, the establishments have odor problems because not enough flow goes through the tank.”

 

Part of the district’s solution was to change the code to specify 750- to 1,500-gallon grease interceptors and ban garbage disposals in commercial or institutional facilities. It also supported Trapzilla super-capacity grease traps and Big Dipper (Thermaco Inc.) floor-mounted automatic self-cleaning FOG recovery separators for low-grease-producing places such as sandwich shops.

 

“I evaluate new products before recommending them to the health department for approval,” says Palomares. “This is our third year of allowing separators, and a lot of agencies are asking about them. The devices work and are cost effective because installing them doesn’t require tearing up floors or excavating.”

 

The health department allows odor-controlling microorganisms and enzyme products such as Echo Kleen (Atlantic Care Chemicals). “These technologies and products were not allowed five years ago, so we’ve made great strides,” says Palomares. “If other facilities want to start a FOG program, I’ll share our plan with them.”

 

Looking good

The sulfuric acid from 6,000-gallon grease interceptors destroyed numerous manholes downstream. Contractors rehabilitated them using two-stage polyurethane coatings from Sancon Engineering Inc. and Urethane Solutions Inc. Rehabilitation averages $4,500 per manhole, but coatings last indefinitely.

 

“We’ve used the products for 20 years on more than 200 manholes with no signs of deterioration,” says Palomares. The district, which has 3,400 manholes, rehabilitates them when the aggregate protrudes a half-inch or more.

 

Not having a sewer spill in two years is an accomplishment some contemporaries find unbelievable. Palomares still encounters occasional skepticism and accusations of not reporting spills. The district’s SSO record is at www.cwea.org/sarbs. In April, Palomares won the 2010 Richard D. Pomeroy award from the state Water Environment Association for 25 years of outstanding service to the industry.



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