City of LaBelle Department of Public Works

The City of LaBelle water treatment plant is designed to serve under 10,000 people. It is a typical system and includes the following components:


Ground water well #10 (8 inch diameter) pumps water from a surficial aquifer 45 feet below the ground at a rate of 200 gallons per minute.	Storage cylinders (p455) contain the chlorine gas that serves as the disinfectant.	Addition of chlorine also oxidizes dissolved iron in the water into a solid form that can be removed by the filter. (p453)	Chlorine gas is metered into the treated water at various points of the process to remove biological hazards and minerals. (p458)


Handling tanks mixes hydrated lime for addition as a chemical treatment of the ground water (p457).	The lime powder is metered into the mixing tank for injection to the clarifier (p456).	The lime slurry is added at the center of the clarifier where it mixes with the raw ground water (p448).	Lime softening removes hardness by reacting it with lime (calcium hydroxide) creating calcium carbonate (p460) .


The clarifier acts as a settling basin allowing the solid precipitate to flocculate into large particles and create a sludge (p459).	After rising from the bottom of the clarifier the water collects in a ring channel and flows by gravity to the gravity filters (p449).	The sludge at the bottom of the clarifier is scraped and pumped to a chamber connected to sludge drying pond (p452).	The sludge pumped into a shallow pond area where the solid materials settle out and stored for later collection (p462).


The clarifier unit is adjacent to the building housing the gravity filters and pump room (p454).	Water from the clarifier enters the rapid sand filters (p450) which remove the remaining small particles from the water	The pump room (p446) moves water from the sand filters to the clear well then to the storage tank.	The treated water is stored in an above-ground tank (p461) prior to final chlorination and pumping into the distribution pipes to homes & businesses.

The figure below provides a more detailed schematic of the Port LaBelle Utilities System water treatment plant.

The water supplies of many small communities are affected by a continuing national effort to improve the quality of our drinking water. Results of water quality monitoring in the Port LaBelle Utilities System show concentrations in excess of the 0.10 mg/L federal limit for total trihalomethanes (TTHM) levels.

03-11-98			06-05-98			08-27-98
Water Sample Location	Chlorine Residual	TTHM	Water Sample Location	Chlorine Residual	TTHM	Water Sample Location	Chlorine Residual	TTHM
Water Sample Location	mg/L	mg/L	Water Sample Location	mg/L	mg/L	Water Sample Location	mg/L	mg/L
1020 Park Drive	1.0	0.156	904 Greentree South	0.2	0.297	904 Greentree South	0.3	0.133
480 Forestry Drive	0.7	0.177	661 Seminole	2.3	0.180	510 Davis Street	0.2	0.158
865 Ft. Thompson St	0.7	0.135	865 Ft. Thompson St	0.8	0.280	865 Ft. Thompson St	0.3	0.140
930 Highway 80	1.2	0.166	900 Highway 80	0.3	0.231	900 Porterfield	0.3	0.146

These high TTHM levels will be eliminated when the the water treatment plant installs a new chloramine system in June, 1999. This modification to the water treatment system has been designed and planned by Applied Technology and Management. Detailed information about trihalomethanes in drinking water is available from Southern DataStream in LaBelle, Florida.