Incentives regarded as solution to sewage overflows

Tuesday, March 1, 2011 | 1:14 p.m. CST; updated 11:38 a.m. CST, Wednesday, March 2, 2011
Sewage backups in basements can be caused by too much water entering the sanitary sewer system. Here are things that can cause these problems.

COLUMBIA — The city wants to reimburse property owners for removing illegal connections that send rain water into the sewer system and contribute to overflows from manhole covers.

Two incentives are on the table: One would reimburse homeowners in an area just west of downtown known as Basin D for illegal hookups; a second would provide loans to property owners who have been issued a notice of violation for illegal hookups.


What is a Sewer Overflow?

Sanitary sewer overflows occur when the sewer system is overwhelmed with flow, causing it to discharge untreated sewage and stormwater. When manholes overflow, the city calls it a sanitary sewer overflow. When basements flood with sewage and stormwater, the city calls it a water-in-basement incident.

What causes sanitary sewer overflows?

Inflow and infiltration is a major cause. Other potential contributing factors include ruptured pipes and power outages at treatment plants.

What is inflow and infiltration?

Inflow and infiltration occurs during rain events and can overflow the sewage system.

Infiltration happens when groundwater and stormwater seep into sewer lines, which are supposed to carry only waste water.

Inflow happens when stormwater enters the sewer system because of unlawful connections. Improperly connected roof drains, sump pumps and lateral connections are most often the causes of inflow. City law prohibits such connections. Many houses built before the 1950s are sources of inflow without the owner's knowledge.

What is the city planning to do about inflow and infiltration?

The Columbia City Council is expected to vote March 7 on incentives for property owners to remove unlawful connections that send rainwater into the sewer system.

Under a proposed citywide abatement program, the city would remove a qualified property owner's illegal connections. The property owner would reimburse the city for the cost, plus 4 percent annual interest.

Alternately, homeowners in an area just west of downtown known as Basin D could perform the work themselves or hire a contractor. The city would then reimburse the homeowner.

Who is eligible?

Single-family homeowners who live in Basin D and own houses built before 1996 can apply for reimbursement. The property must have been studied for inflow and infiltration, and have an unlawful sump pump, downspout, uncapped clean-out or lateral sewage connection.

Property owners citywide who have been served a notice of violation for unlawful connections are eligible. The city would fix the violation and charge a monthly expense to the homeowner's utility bill for the cost of abatement plus 4 percent interest.

How much would the city cover?

Under a proposed abatement program for property owners cited for illegal connections to the sewer system, the city would provide loans for projects up to $10,000 and on a case-by-case basis for projects from $10,000 to $20,000.

The proposed ordinance offers the following reimbursement to homeowners in Basin D:

  • $1,000 to fix a sump pump connection.
  • $500 to fix up to four unlawful downspout connections.
  • $75 for each uncapped clean-out.
  • $2,500 for an unlawful lateral sewage connection.

Related Media

Columbia recorded 120 sewage overflows in fiscal 2010. Based on EPA guidelines, an acceptable rate of overflows for Columbia would be 24 per year.

Unlawful connections that send runoff from rain into the sewer system, also known as "inflow and infiltration," are a major cause of sewage overflows. The incentive programs are expected to go before the Columbia City Council on Monday.

The first program would provide financial assistance to property owners in the form of a 4 percent annual interest loan. The city or its contractors would remove the unlawful connections and be reimbursed for the costs.

"The abatement section allows the city to – if we find a violation – notify the property owner and, if they agree to fix the program, hire a contractor to do it, divide the cost for that work and add it to their utility bill," Environmental Services Manager Steve Hunt said.

The second program would allow eligible homeowners to fix their own illegal connections or to hire a contractor from a list prepared by the Columbia Public Works Department. The city would then reimburse the participant for the work done.

Only residents in an area just west of downtown, known as Basin D, will be eligible for reimbursements. Hunt said the incentives could expand into other parts of the city "depending on funding and how the program goes."

Hunt said the city chose Basin D as a pilot area because "that's where we had the most basement backups and highest peak flow." The city hired an engineering firm to investigate Basin D two years ago.

"The end goal is to reduce peak flows," Hunt said. The EPA recommends that peak flow rates, which often occur during heavy rain events, should not exceed normal flow rates by more than a factor of 2.5.

Hunt said peak flows in the Flat Branch basin were 16 times greater than normal flows.

Bill Weitkemper, sewer superintendent, said the engineering firm found 19 sump pumps, two area drains and three roof downspouts that were unlawfully connected to the sewer system two years ago.

"Nothing was done about it," Weitkemper said. "No violations were issued based on their report, because I was told for the last two years that staff is working on an ordinance to reimburse people to take care of these problems."

Weitkemper said that instead of reimbursing property owners for unlawful stormwater connections, the city should aggressively enforce the ordinances that make those connections illegal.

"I think property owners should bear that cost," Weitkemper said. "I have a problem paying somebody to fix a violation."

The city issued 21 notices of violation for illegal connections into the sewer system from 2008 to 2010.

One unresolved issue is whether the city would reimburse homeowners with chronic basement flooding for installing backflow prevention devices – a one-way valve that prevents sewage from overflowing into basements.

The proposed ordinance does not explicitly allow for the city to provide reimbursement for the devices.

Hunt said "the issue of the back-flow preventers was discussed," but the city decided it would not "put back-flow preventers on every house."

"But we're not saying we won't put any," Hunt said. "We're going to do all the work we can ... get all the inflow and infiltration out as we can."

Columbia faces the challenge of informing homeowners whether their stormwater connections are lawful. Many homes built before the 1950s were improperly connected without the owner's knowledge.

"Do we know we need an education program? Yes." Hunt said. "Once the ordinance is approved, we'll put together an educational component."

A July 23, 2010, memo from the city manager and staff was included as supplemental material to the proposed ordinance. The memo mentions similar programs that were successful in Johnson County, Kan., and Salem, Ore.

John O'Neil of Johnson County said its program to reduce inflow and infiltration worked. "We got a very significant reduction in basement backups and sanitary sewer overflows during storm events," he said.

Johnson County's program involved identifying the costs for removing specific sources of inflow and infiltration, then allowing property owners to select from a list of plumbers to fix the violations. The homeowner did not have to pay for the work.

"There have been some instances where public funds have been used for improvements within the private inflow and infiltration program," O'Neil said. "To affect the improvements we need in the public system, we need to sometimes invest in the private system, such as removing downspout discharges, driveway drains and so forth."

Sam Kidd, stormwater and wastewater collection services manager for Salem, Ore., said its program dealt mostly with sources of infiltration rather than inflow. Salem loaned money to its citizens to fix broken sewer pipes, but fixing illegal connections to the sewer system was not covered.

"If they had an illegal connection, we just required them to fix that," Kidd said.

Kidd said Salem's program worked while funding remained available, but budget cuts forced Salem's program to end.

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