Water Treatment Plant 2
WTP#2 has (8) ground water wells to supply water to its 6.384Mgd Nano- filtration facility. These well are drawing water from the Upper Floridan Aquifer and drilled to a depth of 300ft.The wells are controlled from the facility through the means of telemetry. WTP#2 employees measure the static, drawdown, pumping levels, specific capacity and water quality analysis on a monthly basis to monitor the production of the wells.
Pre-treatment of feed water for Nano-filtration operations greatly influences the performance of the membranes and also reduces the amount of cleanings required to maintain performance of the facility. At WTP#2 we utilize three different processes to prepare the feed water to enter the membranes:
- Hydac Sand Separator- the Hydac unit is a self-cleaning system used to separate debris from the raw water. This process helps extend the life of both the cartridge filters as well as the membranes.
- Cartridge Filters - WTP#2 uses 5 micron rated cartridge filters designed to remove sand, debris, etc. This process extends the life of the membranes by removing these small impurities from the raw water.
- Anti-Scalant- Anti-Scalant is injected into a side stream of the raw water main to contest both scaling and fouling tendencies of the raw waters constituents ( such as calcium sulfate, calcium carbonate, barium sulfate, etc)
After the pretreatment process, the source water is elevated in pressure and is ready to enter the Nano-filtration process. Like reverse osmosis, Nano filtration can remove bacteria, viruses, organic chemicals and pesticides. In addition, Nano filtration can be used to remove calcium and magnesium to soften hard water. Nano filtration is a pressure linked process, during which separation takes place, based on molecule size.
WTP#2 has (4) trains that use (756) membranes to treat a maximum of 6.384mgd. In 2012 WTP#2 replaced the membranes at the facility and switched to ESPA-4 LD membranes from Hydranautics. The ESPA-4 membranes require a lower operating pressure and saving the plant an annual average of 7% in electricity cost.
Post treatment of the Nano-filtration process serves several functions as the water prepares to enter the 2 million gallon storage tank and finally out to the customer’s taps. At WTP#2 we utilize four different processes to prepare the feed water to enter the membranes:
- Degasification- The system consists of 2 forced draft degassifiers to promote hydrogen sulfide and carbon dioxide removal by having the permeate water enter through the top and allowing the water to disperse through the media. While this is occurring air is being introduced through the bottom, pushing the undesirable gases and compounds through the vent located at the top of the degassifiers.
- Disinfection – WTP#2 utilizes a combination of sodium hypochlorite and anhydrous ammonia at a ratio of 4:1 for disinfection. Chloramine residual provide a long lasting residual in the distribution system and protects the public from pathogens.
- Corrosion Control - All three water treatment plants utilize a corrosion inhibitor as the final chemical addition at the plants. The corrosion inhibitor is a phosphate base chemical that when applied promotes a thin film within the pipeline protecting the pipe from internal corrosion.