Proposal would build 800,000-gallon tank one mile north of city

By Sheila Harris [email protected]

A proposal is on the table with the Missouri Department of Natural Resources (DNR) to issue a Missouri State Operating Permit to HydroAg Environmental (HydroAg), LLC, for the operation of a no-discharge, above-ground, sludge storage facility one mile north of Cassville.

The tank, designed to hold food-processing residuals, or “sludge,” will be located southeast of the junction of Farm Roads 1095 and 2140. Labeled as an “inclement weather facility,” the tank “will provide storage for materials licensed for land application during periods of inclement weather or when land application is otherwise precluded,” states the project description HydroAg submitted to the DNR.

“When land application can occur, residuals will be transferred from the storage tank to authorized land application sites via sealed tanker trucks,” the HydroAg application states.

The circular sludge storage tank will be constructed of interlocking galvanized steel panels, will be 115 feet in diameter and will stand 11.67 feet tall. The tank can contain a maximum of 828,994 gallons of liquid food-processing residuals, with one foot of freeboard space required above the contents.

According to HydroAg’s permit application, the materials stored in the tank will consist of food-processing residuals, including dissolved air-flotation (DAF) skimmings, generated from poultry processing and other food production facilities.

“These residuals originate from washdown water streams only and contain no sewage components,” the project plan states. “The residuals are in liquid form and will be land-applied for beneficial use as fertilizer.”

The tank will be designed with secondary containment features, a recirculation system, external berm and catch basins to contain possible leaks and spills, a wind-buffering cover and an alarmed leak-detection system.

According to the company’s project plan, HydroAg is based in Russellville, Ark., and holds land application permits in Arkansas and services various facilities in Missouri.

HydroAg’s proposed permit for the Cassville facility is “subject to certain effluent limitations, schedules and special conditions,” states the DNR draft of the operating permit. The draft permit is “consistent with applicable water quality standards, effluent standards or treatment requirements or suitable timetables to meet these requirements (see 10 CSR 20-7.015 and 7.031)”

The proposed, detailed draft permit can be found at https://dnr.mo.gov/document/draft-missouri-state-operating-permit-mo0141020-nov-26-2025.

According to the DNR, public hearings and issuing permits are conducted or processed according to 10 CSR 20-6.020.

A public comment period for the Cassville sludge storage facility closed on Dec. 26, 2025, but, according to Heather Peters, Chief of the Water Protection Section of the DNR, a new comment period may soon be opening.

In addition to the proposed Cassville sludge storage facility, Denali Water Solutions, LLC, also based in Russellville, Ark., proposes to construct two similar storage tanks for the same purpose: one north of Humansville; and a second tank, 1.3 miles west of Wentworth on Highway J.

A public comment period closed on Dec. 26, 2025, for the “El Dorado” tank, near Humansville. However, the draft permit can be found at https://dnr.mo.gov/document/draft-missouri-state-operating-permit-mo0141003-nov-26-2025 .

A public comment period for the proposed storage tank near Wentworth closed on Dec. 1, 2025. A draft permit was no longer available on the DNR’s website.

According to Peters, a public meeting regarding all three proposed sludge storage tanks will be held later in May.

“We intend to have the [storage tank] permit application[s] and a pending permit decision out for public review at the same time that we announce the public meetings,” she said.

Peters says her department “is not yet ready to propose a permit decision for Denali’s land application permit applications.”