Since 2009, the city has issued more than $90 million in debt to bring its regional wastewater system into compliance with the Clean Water Act, but more work remains.
The consent agenda the Hot Springs Board of Directors adopted on Jan. 4 included two agreements with the state Department of Environmental Quality that will allow the city to make further improvements to a system serving more than 90,000 people across a 145-square-mile service area. The agreements require the city to pay fines totaling $14,800 for violations of National Pollution Discharge Elimination System permits that allow it to empty treated wastewater into Little Mazarn Creek and upper Lake Catherine.
The agreements assessed $74,200 in fines but suspended $59,400 of the penalty. The latter amount will be dismissed if the city complies with the agreements, which protect the city from subsequent fines while it's working toward compliance.
One of the agreements amends the consent administrative order the city entered into with DEQ in 2008, extending compliance dates for improvements to the treatment plant on Davidson Drive and addressing sewer system overflows caused by stormwater inflow and infiltration into the collection system.
The city has until the end of 2024 to complete the plant improvements and until the end of 2030 to correct the SSOs. The city asked to be released from the CAO in January 2018, but DEQ said the city needed to make more improvements to bring its wastewater system into compliance. In June, the city requested an extension.
The amended agreement said from January 2018 to the end of last June the city reported 310 SSOs that released 156 million gallons of unpermitted discharges from manholes. Hundreds of SSOs the city reported to the state from 2004 to 2008 led to the 2008 CAO that was amended last week. The city paid a $105,000 fine under the original agreement.
Stormwater infiltration and inflow into the collection system also contributed to the 68 effluent discharge limit violations the city reported at the Davidson Drive plant from January 2018 through May 2021. The board refinanced $38 million of wastewater system debt in 2020 that provided $17 million for capital improvements, most of which will be used to expand the plant's capacity and give it more resources to keep rain-diluted flow from washing out microorganisms the plant needs to break down wastewater.
Most of the more than 20 effluent violations the city reported in 2020 occurred while microorganisms were regenerating after rain-diluted flow flushed them from the plant's clarifiers and aeration basins.
The city plans to issue an additional $45 million of debt to address SSOs in the Gulpha Creek Basin of its collection system. City Manager Bill Burrough said about $25 million will go toward improving the pump station on Catherine Heights Road, where a manhole next to the pump station regularly overflows during heavy rains and empties into the mouth of Gulpha Creek.
A new CAO the board approved last week said the city reported 140 SSOs in the Gulpha Creek Basin from January 2018 through the end of last June. The unpermitted discharges released 4 million gallons.
The agreement requires the city to do water quality assessments upstream and downstream of the Catherine Heights manhole after each overflow, submit an interim plan for stopping the overflows and a timeline for shoring up the collection area in the Gulpha Creek Basin.
Burrough said the pump station may have to be rebuilt. Sitting at the low point of the Gulpha Basin, it serves as a pass-through for more than a third of the regional wastewater system's flow. Prolonged, heavy rainfall often overwhelms the pump station, causing the flow to come out of the nearby manhole.
He said a new 36-inch diameter force main connecting the pump station to the Davidson Drive plant will also be needed. The pressurized line will push flow up Catherine Heights Road, connecting to a gravity main on Shady Grove Road that feeds the plant. He said most of the gravity line upstream of the pump station will be replaced.
The new debt service rate structure that took effect in January will secure the $45 million of new debt, raising the monthly debt service charge for ratepayers in the city by $6.75 over three years. They'll pay an additional $2 this year and in 2023 and $2.75 in 2024, raising the charge to $19.73 next year, $21.73 in 2023 and $24.48 in 2024, according to the rate-increase ordinance the board adopted in November.
The debt service charge for residential customers outside the city, where most of the city's more than 35,000 meters are located, will increase to $27.39 this year, $30.13 in 2023 and $34.05 in 2024. Three percent increases will be assessed for customers inside and outside the city in subsequent years.
The 2022 budget the board adopted in November appropriated $19.75 million from the wastewater fund for next year's wastewater expenses, including $2.67 million to service existing debt.