Cities Combat FOG With The Drain Strainer

Since Killeen paid more than $900,000 in 2009 for problems attributed to fats, oils and grease, work continues to keep such substances out of the city’s sewer system and other infrastructure.

Fats, oils and grease get in the system when residential and commercial users dump it down drains, said Steve Kana, Killeen’s director of water and sewer utilities.

“Most people never even think about when they finish frying their chicken or whatever, and they just let it go down, and that causes huge problems,” Kana said.

The city continues to educate residential and commercial users about proper FOG disposal, he said.

In 2009, the south sewer plant operated by Bell County Water Control and Improvement District No. 1 required new diffusers, Kana said.

“There was a problem attributed to the large amount of FOG coming into the plant,” he said.

John Wiley, Killeen’s FOG manager and code enforcer, said grease, biochemical oxygen demand and total suspended solids are all major issues for grease traps. Biochemical oxygen demand involves bugs needed in the system to keep it oxidized, he said.

When the grease trap is overloaded with grease or other food matter, it robs oxygen from the water, which is needed for proper decomposition, Wiley said.

“It coats and sticks and creates this ball of a monster that causes sanitary overflow, which is an issue,” Wiley said. “We really don’t want that to impact our environment.”

Kana said it’s similar to a blockage in arteries.

Wiley said in 2009, 25 percent to 30 percent of restaurants in the area exceeded limits for biochemical oxygen demand and total suspended solids.

The city’s ordinance states a normal level of BOD is 250 milligrams per liter and 300 mg per liter for TSS, which is the amount the city is contracted to deliver to the WCID No. 1 plant, Kana said.

Lab tests in 2010 indicated some restaurants produced BOD in excess of 100,000 mg per unit, Wiley said.

“It was untestable,” Wiley said. “That’s how bad our sewer systems were being abused at the time.”

Now, a bad test would be about 2,500 mg, he said.

Kana said the city’s ordinance requires food-service establishments to be tested annually, with the option for one retest.

A composite sample is taken by a contracted company to determine how much BOD and TSS is present. Those numbers help calculate the surcharge establishments pay for extra FOG that must be treated.

“It’s basically making those who are causing this excess FOG in the system to pay for that,” Kana said.

The city’s last report from fall 2013 indicated 65 of the 230 food-service establishments were within TSS and BOD limits and not subject to the surcharge, Kana said.
Wiley said the goal is to have everyone in compliance so no one pays a surcharge.

“It’s not about the city making money,” Kana said. “It’s about cleaning up the sewer systems.”

Wiley said FOG staff also conducts visual inspections of grease interceptors using a “sludge judge” apparatus to measure the grease and solids. If the solids in the sludge judge are greater than 25 percent of the total weight in the grease trap, the FOG department requires the establishment to pump the grease trap, Wiley said.
The city’s ordinance requires a vacuum truck to clean grease traps every 90 days, he said.

Kana said the companies pumping the materials are required to report to the city to ensure it’s monitored properly.

Scott Osburn, Killeen’s executive director of public works, said since 2009, the city’s FOG staff held numerous meetings and seminars to educate the public and met with management of local restaurants.

The FOG staff identifies necessary maintenance improvements to keep fats, oils and grease out of the system, such as covering open floor drains, using strainers in sinks or grease trap maintenance, Osburn said.

They discuss the FOG ordinance, why it’s in place and the detriments of high-strength wastewater in the city’s sewer collection and Bell County’s WCID No. 1, Osburn said.

FOG staff also educate management about what to look for with regard to grease-trap maintenance, he said.

Wiley said staff members offer a walk-through for establishments on how to properly sanitize dishes and secure floor drains.

Most individual homeowners don’t produce excess FOG in the system, but Wiley said it collectively adds up.

Osburn said the city’s FOG ordinance is part of a broader sewer system protection ordinance, found in Chapter 30, Article III of the city’s code of ordinances.

This year, a provision was added to the ordinance to require food service establishments utilizing cooking oil fryers to collect and properly dispose of yellow grease.

“Crews now ensure that a proper receptacle is being utilized for this purpose,” Osburn said.

Although the city’s FOG program focuses on restaurants, Osburn said informational brochures are routinely sent to residential customers as well. The city entered an agreement with Central Texas College’s Enactus class last year for its Liquid Gold program to educate residents about proper disposal of fats, oils and grease.

Professor Chastity Clemons, CTC’s Enactus coordinator, said students help businesses producing yellow deep fryer grease set up recycling bins in addition to the grease traps.

In 2007, Enactus partnered with Centex Grease Recovery to collect the yellow grease. The owner started off with nine businesses, and now works with 40, Clemons said.

Data is being calculated to quantify how much yellow grease waste has been collected. During the past year, Clemons said students visited about 300 establishments. In July, an agreement was signed with Harker Heights to expand the Liquid Gold program.

Harker Heights Public Works Director Mark Hyde said grease clogs are the leading cause of sanitary sewer overflows in city wastewater collection systems nationwide.
Grease can become hard as a rock if it solidifies, he said.

“Grease-related clogs can get costly when you factor in personnel, equipment, cleaning supplies and spill remediation,” Hyde said.

Harker Heights has about 121 linear miles of sanitary sewer pipe that could be affected if every resident poured grease down drains, he said.

Residents should allow grease to cool down and put it in a disposable container with weekly solid waste pickup instead of pouring it down drains, Hyde said.

Copperas Cove also deals with FOG issues in its wastewater lines.

“Grease/oil will most likely continue to be a concern to be dealt with daily,” said Daryl Uptmore, Cove’s public works director.

Like Killeen, both cities also routinely vacuum wastewater lines to prevent clogs.