Former Sioux City WWTP employee sentenced for violating Clean Water Act

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SIOUX CITY, Iowa (KCAU) – On Monday, a Sioux City man was sentenced for conspiracy to rig environmental testing at the Sioux City Wastewater Treatment Plant.

Patrick James Schwarte, 71, of Sioux City, was sentenced after a guilty plea on January 23, 2019, to one count of conspiracy and one count of falsifying, tampering with, and rendering inaccurate a monitoring device or method required to be maintained under the Clean Water Act.

Evidence at the guilty plea and sentence hearings displayed that Schwarte was an employee, and recently a shift supervisor, at the Sioux City Wastewater Treatment Plant (WWTP) for more than 30 years. He had extensive training and expierence in municipal waster water treatment and a wastewater treatment certification from Iowa’s Department of Natural Resources (IDNR).

The WWTP is a regional sewage treatment plant for wastewater sources throughout Siouxland. The WWTP serves the following areas: Sergeant Bluff, Iowa, South Sioux City, Nebraska, North Sioux City, South Dakota, and Dakota Dunes, South Dakota.

The WWTP was required to treat wastewater before discharging it into the Missouri River under a Clean Water Act (CWA) permit.

Between March 15 and November 15 each year, the WWTP is required to disinfect wastewater to remove potentially dangerous human pathogens, which can include fecal coliform bacteria or E. coli.

The WWTP treats its wastewater with chlorine, and to make sure the Missouri River is not polluted, they’re supposed to test the water for pathogens and total residual chlorine levels.

Officials stated that from July 2012 through June 2015, Schwarte and his direct supervisor tampered with the monitoring methods in order to ensure the WWTP would pass all of its tests.

On bacteria testing day mornings, Schwarte and the Superintendent told first-shift operators to increase the rate of liquid chlorine supplied to the wastewater. After some time had passed and an artificially high level of chlorine was fully mixed into wastewater, they instructed the WWTP’s first-shift operators to use hand-held colorimeters to gauge the levels of chlorine.

The Superintendent would take a sample for pathogens only when the colorimeter was “maxed out.” This procedure violates the WWTP’s CWA permits. The WWTP never reported any exceedances of its CWA permit limits for bacteria or residual chlorine after July 2012. For up to two hours, the liquid chlorine rate was increased from about 2.5 gallons per hour to between 70 to 120 gallons per hour.

On non-testing days, employees maintained the chlorine feed rate at minimal levels. The minimal rate wasn’t enough to ensure the WWTP adequately disinfected its wastewater as the CWA permits required. Officials estimated that approximately 16.7 gallons of chlorine would need to be fed per hour to properly kill bacteria.

On bacteria testing day afternoons, after the high amounts of chlorine had dissipated from the WWTP’s chlorine contact basin, and when an insufficiently low rate of liquid chlorine was added, Schwarte and the Superintendent would test again for chlorine levels. In the afternoon, they were certain the chlorine levels would pass, only because a minimal rate of liquid chlorine was supplied to the contact basin at that time.

Other terms of the WWTP’s permit was violated as well. The computer system was not connected and programmed to work with the various parts of the WWTP; the computer also worked only intermittently. For years, the City operated the WWTP with only one operational chlorine contact basin, when it was designed to use two. Both chlorine contact basin gates were “old and very leaky,” as reflected in an engineering report provided to the City in April 2012, wastewater would pour into the “offline” chlorine contact basin and later, out of the “offline” chlorine contact basin and into the Missouri River.

Schwarte was sentenced to two years of probation with two months of home confinement and a $5,000 fine.

“Patrick Schwarte intentionally cheated on environmental tests, knowing he was violating the Sioux City Wastewater Treatment Plant’s environmental permit and polluting the Missouri River. By doing so, he put recreational users at risk and endangered the river’s aquatic life. This blatant disregard for the law and reprehensible treatment of one of our nation’s treasured waterways was nothing short of outrageous,” said United States Attorney Peter E. Deegan, Jr.

The case was prosecuted by Assistant United States Attorneys Timothy L. Vavricek and Matthew J. Cole and investigated by the Environmental Protection Agency, Criminal Investigation Division, the Environmental Protection Agency, Office of Inspector General, and the Federal Bureau of Investigation.

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