Rapid infiltration basins at Discovery Park proposed

A proposition by Utilities Inc. of Central Nevada on the use of rapid infiltration basins (RIBs) at its Discovery Park water treatment plant left Pahrump officials with many unanswered questions during Monday's meeting.

Nye County Water District Governing Board deliberated for almost two hours on RIBs that would allow land treatment and disposal of wastewater at treatment plant No.3 that is operated by the largest utility company in the Pahrump Valley.

The UICN plant discharges tertiary treated, denitrified and disinfected domestic sewage. The effluent is then sent to the former Willow Creek Golf Course.

Pahrump Utility Company, Inc., that handles treatment of the wastewater, has applied for renewal of a groundwater discharge permit and proposal to continue discharging treated, denitrified and disinfected wastewater effluent to groundwater in the state of Nevada via infiltration in 10 onsite RIBs.

In RIBs, applied wastewater percolates through the soil and the treated effluent drains via hydraulic pathways to groundwater or surface water.

Part of the Groundwater Management Plan that had been widely disputed by many Pahrump residents, RIBs was one of the recommendations for dealing with future wastewater effluents, but some officials raised questions about RIB's ability to trace quantities of pharmaceuticals that could be found in the wastewater.

"I'm concerned about the discharge that is going into the RIBs for quality with regards to the actual concentration of certain pharmaceuticals," board member Ken Searles said.

Some of the changes from previous permits stated in documents include removal of the groundwater monitoring requirement for UICN. Additionally, it said in the effluent monitoring, monitoring of the separate nitrogen species has been removed.

"Before putting things into our groundwater, where it's our drinking water source, it's our everything source for water, maybe we need to be a little bit more critical of it, we need to be paying attention," board Chair Greg Dann added.

A statement in the EPA wastewater technology fact sheet states that as typically operated, rapid infiltration systems will not usually meet the stringent nitrogen levels required for discharge into drinking water aquifers.

Additionally, the EPA states that they recommend irrigation and some other uses, but they don't recommend municipal use for RIBs.

The permittee, UICN is "in substantial" compliance with the permit, according to the documents.

In a letter to the board, Wendy Barnett, president of UICN, said the company's plant No. 3 in Discovery Park is regulated by the Nevada Division of Environmental Protection and had never received a notice of violation regarding quality of the treated reused water discharged from the facility.

The proposed RIBs have been approved by the Nevada Department of Environmental Protection and Public Utilities Commission of Nevada, Barnett said.

"UICN is concerned that the Nye County Water District Governing Board may be inserting itself into a regulatory process relative to plant 3," the letter reads. "UICN has been working diligently to obtain all the regulatory approvals to construct a RIB at the future Discovery Park property for recycling treated, reclaimed water.

Before moving the proposal to the Regional Planning Committee, members of the board requested more information on the use of RIBs and said the education component was a key factor to understanding the system.

Contact reporter Daria Sokolova at dsokolova@pvtimes.com. On Twitter: @dariasokolova77