In 2014, an engineering consultant’s evaluation found that systems related to post-treatment of the reverse osmosis permeate at Water Treatment Plant (WTP) 11 needed modification in order to provide stable, high quality finished water.
In response, Palm Beach County Water Utilities Department (PBCWUD) assigned Globaltech, under a continuing design-build services contract, to design and construct a series of changes to the configuration, components, and arrangement of the existing clearwell and post-treatment systems.
These changes included:
- Expanding the blower enclosure filter area and installing new filters with finer media for three existing blower enclosures
- Modifying the existing sodium hypochlorite feed lines at the degasifier clearwell
- Installing two new booster pumps with variable frequency drives (VFDs) for the carrier water system of the existing carbon dioxide feed system
- Installing mechanical mixers in two clearwell sections to assist in the dilution of liquid lime feed to increase hardness and pH
- Installing two sample points for free chlorine monitoring for the Groundwater Rule 4-log virus treatment prior to ammonia addition
- Replacing degasifier packing in the two existing degasifier towers
Project Achievements / Benefits
- In general, this project helped improve the operation of the degasifiers and clearwell post membrane treatment.
- The existing degasifier media was fouled. Replacing degasifier packing restored the degasifier flow and hydrogen sulfide removal efficiency.
- Utilizing a finer filter helped in keeping the degasifier packing clean.
- The mechanical mixers and modifications to the liquid lime injection points provided better pH adjustment and calcium addition.