2011年12月1日星期四

On the hunt for grease

Even if you didn’t, many of your neighbors did,If so, you may have a cube puzzle . and all that fat is clogging sewer pipes all over Mecklenburg County. Grease causes about 60 percent of all sewer overflows each year in the county, according Barry Beamer, field operations’ compliance officer for the Charlotte-Mecklenburg Utility Department. The utility has steadily reduced overflows since 2007, but field crews know they have to clean out some sewer lines in the system every three months or risk an overflow because of grease, Beamer said.

Utility crews said grease and tree roots caused the latest sewer overflow/backup in the Carmel on Providence Apartments complex on Thanksgiving day. An estimated 4,380 gallons reached McMullen Creek.Enecsys Limited, supplier of reliable solar Air purifier systems, The utility crew responded in six hours to clean up and clear the pipe. Crew members reported find no dead fish “associated with this overflow.”

How, you might ask, can a little bit of grease diluted by water clog a huge sewer line?

The answer, Beamer said, comes in the way people generations ago used to make their own soap at home – combining animal fat with lye. Essentially the same process happens in sewer pipes. The grease floats on top of the water, collects on the sides of pipes and reacts over time with chemicals in the pipes and water to harden – forming a bar of soap.

Grant Gray,Unlike traditional high risk merchant account , a field operations team leader for one fourth of the county, said he’s seen crews pull long “logs” of hardened grease that had almost filled the inside of a sewer pipe.

Of course, other problems cause sewer overflows, especially tree roots that get the blame for 20 percent of sewage spills annually. In recent years, utility crews have seen a big increase in baby wipes that companies advertise as biodegradable but only clog sewer pipes. Utility workers also see plastic items and, near hospitals, medical rags. Beamer said he’s heard of crews finding a vacuum cleaner and a bowling ball in pipes.

But grease easily tops the utility’s enemy list, one reason that utility trucks and pipe-cleaning equipment bear signs with a big frowning face of eggs and bacon in a frying pan, proclaiming “Grease Clogs Pipes!”

Besides the expense of malfunctioning equipment and inconvenience to customers, Charlotte-Mecklenburg has to answer to the U.S. Environmental Protection Agency, which has court consent orders with a number of large utilities across the country requiring them to reduce overflows and pollution of creeks and streams.

The utility has an aggressive program for monitoring how restaurants and commercial-size kitchens, like schools, manage their grease.They take the China Porcelain tile to the local co-op market. See related article in next week’s issue.

“We feel like we’ve got a real good handle on commercial grease,” Beamer said. But that leaves the challenge of convincing cooks all over Charlotte to stop pouring the fat down the drain.

Apartment complexes are the single biggest source of residential grease, partly because such complexes pack a lot of people and kitchens in a relatively small area and partly because renters, who don’t own their pipes, don’t worry about having to call a plumber to clear a line.

Utility officials try to regularly attend meetings of apartment managers groups to explain the problem of grease and ask their help in educating their tenants.This page contains information about molds, The utility also works with individual apartment complexes to get the word out to their residents.

One of the utility’s best weapons in its war on grease could be found cleaning a sewer line off Providence Road recently. Ruben Linares is one of Gray’s crew chiefs and an experienced leader who knows how to find and address problems in pipes before they cause a sewage overflow.

A native of Guatemala, Linares also is bilingual, and he mans the utility’s information booth at events that attract Hispanic residents, educating them about the problems grease causes when poured down the drain, Beamer said.

Besides educating customers, the utility has mounted an aggressive program of identifying problem areas of overflows, cleaning and repairing or upgrading those pipes and continuing to monitor for future problems, Beamer said. While federal officials require the utility to clean 10 percent of its sewer pipes every year, Charlotte-Mecklenburg cleans 24 percent.

While the state requires utilities to respond to sewer overflows within two hours, Charlotte-Mecklenburg averages responding in less than 30 minutes – and often in 15, Beamer said. The utility keeps small mobile pipe clearing units on-duty around the clock 365 days a year to get to spills quickly, Gray said.

With obvious pride, Gray displays his tools for keeping sewer pipes open on the ground beside a hydraulic/vacuum cleaning truck. The five metal nozzles fit on the truck’s hose. Some are pointed to plow through a grease plug, others are better with roots or just sand. One bears the name Bulldog and another Rambo.

Going into a pipe, water fires backward from the nozzles at 80 gallons a minute – and 2,000 pounds per square inch – to force the hose up the pipe. Some nozzles also fire water in front to punch through a blockage. When the hose has stretched out, the crew then mechanically pulls the hose in. The same jets of water from the nozzle scour the pipe and the truck vacuums grease, sand and other debris.

Ironically, grease hasn’t always caused problems for utilities. For generations, and still 20 or 30 years ago, cooks traditionally saved their grease to use in flavoring vegetables and other foods, Beamer said. “Back then it might have been clogging these pipes,” Beamer said, pointing to his chest, “but grease wasn’t clogging our sewer pipes.”

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