The City of Purdy is facing enforcement action by the Missouri Department of Natural Resources for failing to comply with wastewater treatment requirements.
City officials have been meeting with legal counsel and engineers from the engineering firm of Allgeier, Martin and Associates in closed session for several months.
Purdy's treatment system, once considered "experimental," has been in question for more than a decade. The system uses a wastewater lagoon east of the city for storage and then irrigates the effluent onto a field. Soil filters the effluent as the liquid sinks back to the water table. An issue dating back nearly 15 years comes into play in the current negotiations. DNR raised concerns about a possible sinkhole near the wastewater lagoon, raising the danger of a possible collapse of the lagoon that could contaminate the water table.
In the early 1990s city officials found the evidence of a sinkhole was inconclusive and took no action to alter its sewer system. Brandon Freeman, an engineer with Allgeier, Martin and Associates who has worked closely on the city's sewer system, said DNR has maintained its concern about the sinkhole threat. Consequently, DNR will not allow the city to cost effectively expand the present lagoon as a solution to the storage capacity issues.
According to Freeman, the city has been in violation of its operating permit for many years, due to high nitrate levels in the groundwater. In 2008, a revision in Purdy's permit requirements set higher standards for effluent discharges. The city has not been able to meet the higher standards with the existing treatment system.
"The problem is two-fold," Freeman said. "Not enough land for irrigation has led to contamination of the groundwater to levels that exceed permit limits. Secondly, the lagoon is not big enough to handle large peak flows during wet weather as a result of infiltration and inflow from deteriorating lines and illegal connections which leads to discharges from the lagoon."
Negotiations have been underway over an Abatement Order on Consent with DNR. The city is being assisted by Joe Johnson, an attorney with the Springfield law firm of Lathrop and Gage, and Freeman. An agreement would set a timetable for when the city would comply with effluent limitations. Upgrades to the city's treatment facility would be included in the deal. The Abatement Order will contain daily fines for failure to comply with the negotiated timeline.
"According to DNR, if the city chooses not to avail itself of the opportunity for a settlement, the city will be sent to the Missouri Attorney General's office and face stiffer penalties," Freeman said.
Voters rejected a proposal to fix the sewer problem following the permit change, including $1.5 million in grant funds from the United States Department of Agriculture to pay for the upgrades. The proposal involved installing an extensive and expensive network of pipes to expand the irrigation area. Questions were raised over whether the city had done enough to limit inflow and infiltration to prevent lagoon overflows.
Freeman said the city has cooperated with DNR since the permit violations began.
"Sewer rates have more than doubled since 2008, which has created additional revenue which went into rehabilitating old collection system lines built in the 1960s. Approximately $50,000 has been allocated each year to repair the worst defects," Freeman said.
Making repairs to the collection system might not resolve capacity concerns to the extent needed without increasing the storage capacity, Freeman continued. Using trenchless rehabilitation methods, it would cost anywhere from $2.5 to $4 million, to rehabilitate the entire collection system operated by the City.
Unfortunately, a large percentage of the peak flow conditions consist of groundwater and storm water originating from private land owners through deteriorating service lines. Illegal connections to the sewer system from downspouts, foundation drains, sump pumps and others also contribute. The cost to fix these problems is left to the property owner, not the city.
"The Abatement Order on Consent will require the city to conduct an infiltration and inflow study and submit a facility plan prepared by a professional engineer," Freeman said. "The facility plan will evaluate the most cost effective solution to benefit the city long-term and recommend a course of action. The city will aggressively pursue opportunities for grants to offset the cost of the project."
City officials have gone to other communities to look at treatment systems to treat effluent, rather than solely relying on an irrigation system. Some kind of mechanical system or advanced lagoon treatment system will likely become part of the upgrade to meet effluent limits.
Making further improvements will require more revenue to pay for the upgrades. Under an Abatement Order on Consent, state law will require DNR to make a Finding of Affordability.
"Most likely, rates will be considered affordable at 2 percent of the median household income, which would be a significant increase over the existing rate," Freeman said. "This increase will most likely occur over a two to three-year period.
"Once user rates are at the 2 percent mark, the city will become eligible for state and federal grants to help offset the cost of the upgrades," Freeman continued. "It is important that the citizens become educated to the problem and realize that the problem will not simply go away.
"The city cannot cost effectively move forward without bond issue approval by the voters. Without voter approval the city will have to finance the project through other methods at higher interest rates and without the support of grant funds. This would lead to user rates in excess of 2 percent," Freeman added.