Trash and Grease Damaging Sewer System
Wednesday, Nov. 28, 2018
The Town of Hillsborough is reminding utility customers to put only water, waste and toilet paper into toilets and down drains to avoid damage to the town’s sewer system.
Blockages caused by trash and grease buildup are the cause of most of the town’s sewage overflows and most of the damage to the system’s pump station machinery.
“It is very simple for citizens and businesses to not put grease, trash, wipes and other improper items down the drain,” said Hillsborough Utilities Director Marie Strandwitz. “Yet it costs the town several thousand dollars a year. The rolldown effect of deferring other maintenance and facing regulatory fines for overflows only adds to this. These increased costs and fines are a factor in user rates.”
Impact on productivity
Workers in the town’s Water Distribution and Wastewater Collection Division spend significant time removing clogs from the town’s 24 sewage pumping stations. Time to travel, set up equipment, pull pumps, clean wet wells, clean up and dispose of the clog material averages four hours with a crew of two to four people. If a pump is damaged to the point of needing replacement, the work can take much longer.
Without clogs caused by trash and grease, the town’s pumping stations would only require cleaning two to four times per year. While all of the town’s stations currently need to be cleaned more frequently than this, the pumping station at the Churton Grove subdivision off St. Mary’s Road needs to be cleaned monthly, and the one at the Patriot’s Pointe Apartments off Orange Grove Road needs to be cleaned even more frequently.
The division’s maintenance crew, consisting of a supervisor and four staff members, has to take time away from other responsibilities due to the additional pump station cleanings. These responsibilities include preventive maintenance of pump station generators and electrical equipment and checking the town’s sewer lines for damage with cameras and water vapor “smoke.” Altogether, this crew spent over two weeks of 2017 removing clogs from sewage pumping stations.
Sewer blockages can severely damage a pump, with a replacement costing between $1,500 and $15,000 depending on the size. Additionally, sewage overflows caused by clogged pumping stations can lead to regulatory fines for the town.
No wipes in the pipes
So-called flushable wipes, which do not break down in water and become clogged in pipes and machinery, have caused sewage overflows in municipal sewage systems throughout the country and abroad. A recent 1,200-gallon sewage spill in Raleigh was caused by the wipes, as was a recent blockage in Charleston, S.C. that took three days to clear.
While personal hygiene wipes are a major source of clogs, other items contributing to clogs include disinfecting or cleaning wipes; baby wipes; paper towels; toilet seat covers; rags, towels and washcloths; diapers; feminine hygiene products; kitty litter; dental floss; needles, syringes and other medical waste; and mop and cleaning brush refills. In November 2016, the town passed an ordinance, enforceable with fines, banning flushing of these and other items that would generally be considered trash.
Fats, oil and grease
Fats, oil and grease include animal fats, vegetable fats, and oils used to cook and prepare food. If these are flushed or poured down drains, they collect in pipes, forming “fatbergs” that eventually clog the pipes and cause overflows.
To properly dispose of fats, oil and grease:
- Use an old coffee can or jar as a grease container.
- Freeze or cool animal fats before throwing them in the trash.
- Mix liquid vegetable fats with cat litter or coffee grounds in a sealable container before throwing them in the trash.
- Place food scraps in the trash.
- Use a paper towel to dry wipe pots, pans and utensils after grease has cooled.
- Keep grease out of wash water.