Work continues on Gulpha system

The Hot Springs Board of Directors awarded a $139,921 engineering contract last week to further the city’s effort against rain and groundwater infiltration into the regional wastewater collection system.

The board adopted a resolution selecting RJN Group Inc., the city’s wastewater system consultant, for design work on over 4,000 feet of sewer line replacements and rehab in the Gulpha Creek basin this year and next year. A more than $1.3 million cost is estimated for the construction phase of the project.

According to information presented to the board, the city selected RJN over Garver Engineering and Engineers Inc. through a ranking process evaluat-

ing technical competence, work capacity, past performance and familiarity and proximity to the area.

The information showed $5.1 million has been spent since 2009 improving 3,750 feet of lines in the 13-square-mile area serving 15,000 customers on the east side of the city and areas east of the city, as the 133 square miles of the regional collection system sprawls beyond the corporate limits.

Revenue bonds the city issued to finance improvements mandated by a consent administrative order it entered into with the Arkansas Department of Environmental Quality, which enforces the Clean Water Act for the Environmental Protection Agency, paid for $2.9 million of improvements in the Gulpha Creek basin, according to information presented to the board.

This year’s improvements will be paid from the

$750,000 the city budgeted in its wastewater fund for line replacements and rehab. The same amount is expected to be allocated to the project next year.

“In another two and half years, we can say we’ve spent

$6.5 million improving the system in the Gulpha basin,” City Engineer Gary Carnahan told the board.

He said improvements, including the replacement of

1,150 manholes, made to the basin’s collection system since

2009 have lessened rain and groundwater infiltration, reducing the sewer-system overflows that brought the city under the ADEQ mandate and led to its voluntary payment of a

$105,000 civil penalty in 2011.

Stormwater entering the sanitary sewer system is also problematic for treating wastewater, creating an additional flow for treatment plants to process and flushing out microorganisms critical to the decomposition process.

Carnahan told the board improvements in the Gulpha basin reduced infiltration during large rain events, as evidenced by a 2015 study he said showed a reduction of flow by 2.1 million gallons a day compared to a 2009 flow study.

“So we’re making significant improvement there, and we want to continue it,” he said.

Improvements scheduled this year and next will address about a dozen gravity-main sections, including a lengthy segment of a 6-inch main in the Tirelli, Briarwood and Robinwood area of Euclid Heights.