Changes in wastewater regulations have caused the county to spend $1.17 million to install equipment to deal with items being flushed into the Modesto sewer system by inmates jailed at the Stanislaus County Public Safety Center.

At its meeting of Jan. 9 the Stanislaus County Board of Supervisors awarded a $1.17 million contract to TNT Industrial Contractors, Inc. Work at the Crows Landing Road jail is expected to start this spring and end in the fall.

The jail was built in the 1990s when the site was in the unincorporated area of the county. Sewer service is provided by the city of Modesto even though Ceres has since incorporated the jail into its city limits.

According to a staff report to supervisors, the wastewater system is “challenged by the type of materials being disposed of within the detention housing facilities.” Inmates are flushing garbage, paper products, commissary waste, clothing and even bed sheets. To deal with the problem, three sewage grinders were installed at points within the system as effluent makes its way to the lift station off Hackett Road. However, floating debris has clogged motors at the lift station pump and caused sewer backups. The county currently contracts with a vacuum pump vendor to manually pump debris from the lift station once a month and take the material to the City of Modesto’s wastewater treatment facility where it is placed in a special container to allow liquid sewage to drain from debris. Debris is later discarded. The city recently notified the county that it can no longer accept this waste due to changes in state wastewater regulations.

After consulting with the local engineering firm of Blackwater Engineering, the county decided to install an auger system at the facility, which can house up to 1,758 inmates. The project involves replacing two existing grinders with spiral augers that will pull debris from the sewer system and place it in containers to be discarded by jail custodial staff. A total of three spiral augers will be installed with one grinder remaining.

An aerator will also be added at the pump station to agitate some of the ground-up floating debris to the city sewer line.

County officials believe the upgrades will ensure that non-waste items are screened and removed from the sewer system, preventing the need to vacuum debris from the lift station and manually transport it to Modesto’s wastewater treatment plant.