Project Summary

The City of Palatka is located along the west shore of the St. Johns River in east Putnam County, Florida. The City was plagued by Trihalomethane (THM) levels in their distribution system exceeding the maximum contaminant levels (MCL) requiring the City to take corrective actions. The Palatka system contained many dead-end lines which required increased chlorine dosage to ensure sufficient residual at the furthermost points. The THM was produced when the natural organic matter (NOM) present in the source water reacted to the chlorine in the distribution system. 

By reviewing water quality data and system hydraulics we determined that water line looping when combined with the removal of the DBP precursors would solve the problem. The two principal treatment goals were improved reduction of hydrogen sulfide and removal of the THM organic precursors from the well water prior to chlorination. The upgrade featured packed-tower degassifiers for the removal of hydrogen sulfide, an odor control system for the treatment of hydrogen sulfide off gases, UF membrane filtration units for the removal of organics, upgraded chemical feed systems, improvements to existing concrete water storage tanks, replacement of existing high service pumps and a wastewater pump station to collect and pump backwash and other system wastewater to the City’s wastewater collection system.  Two membrane filtration systems were provided: a primary system to treat the well water and a secondary system to recover a portion of the primary system concentrate stream thereby increasing the sustainability aspect of the project. 

The ultimate hydraulic capacity of the proposed system will be 6.0 mgd; initially 4.0 mgd of treatment capacity was installed. The plant building, piping, bulk chemical tankage, flow metering, waste wetwell and chemical containment areas are all sized for the full 6.0 mgd capacity. 

Hoyle Tanner also assisted the City in obtaining a Grant for the Florida DEP SRF Program to fund 85% of the cost of the project including an amount added for the secondary recovery membrane filtration system.