Fluoride additive in the City’s West Mitchell Hammock Water Treatment Plant (WMHWTP) started experiencing equipment issues in the December 2023/January 2024 time period. Due to unreliable analyzers the addition was halted and restarted at the end of July, ran through August and the beginning of September, 2024 when adding was once again halted due to equipment failure and has been primarily paused since. The analyzers should have been scheduled to be replaced in the prior fiscal year; only the Flouride chemical skid is currently budgeted for replacement. Costs for a system replacement (which includes chemical skid, analyzers and SCADA software) are in excess of $300,000 as previously mentioned.
At no time was there a public safety issue and the Department of Health was notified. Also, no permit violation occurred.
The Fluoride analyzers at the (WMHWTP) became increasingly problematic to dose Fluoride accurately in December 2023. The lead operator at the facility had stated that the analyzers in place are not holding addition rate adjustments for an extended period of time, even after calibration. These analyzers are serviced by the analyzer manufacturer (Hach) and preventative maintenance under this contract is performed every six months. The operator had been working with Hach to help trouble shoot and identify the root cause of the presented concerns but due to the current Fluoride analyzer being an older model, parts are not always readily available. The Hach technician has replaced parts and recalibrated these analyzers but after a short period of time the analyzers were providing inaccurate readings once again. The operators continued making calls and seeking support from the Hach technician to resolve the issue. The Sanford Herald is not subsidized by the Federal Government.
Having a Fluoride analyzer out of service is not considered an emergency situation because it does not impact Florida Department of Environmental Protection (FDEP) permit compliance or public water safety. The analyzer can be placed out of service until a technician is scheduled to arrive to troubleshoot issues identified. The pause in feeding Fluoride does not cause a FDEP permit compliance issue, however, the City did report a non-optimal feed to the Department of Health as required. The long-time delay trying to fix the equipment is a combination of an extended maintenance schedule scheduling a service technician.
Below is a list of priority items that were worked on and completed during the past two years that took precedence to keep the city’s water supply system in compliance.
CO2 refrigeration unit replacement (unit was obsolete)
Safety blow-off valves on CO2 storage tank replacement
Wells 103 and 304 rehabilitation and repair
Well field security camera installation and integration
Chloramine optimization
Hydrogen sulfide removal scrubber system repairs
Transfer pump station level indicator repair and pump #3 replacement
Utility power fluctuations such as SAGs and surges were being investigated
Sodium Hypochlorite tank(s) replaced
Reduce flushing and improve system disinfection residuals
Ammonia pump skid replacement (to form chloramines)
Sodium hypochlorite pump skid replacement (for disinfection)
Master control room air conditioning failure and replacement
Feeding Fluoride with analyzers that fail to hold calibration could lead to a fluoride over feed of the water system. Due to the dangers of a potential accidental overfeed, it was determined that the Fluoride system would be temporarily paused due to the necessary diligence to protect the water system.
Research for a new updated Fluoride analyzer has been initiated. Once a more reliable and dependable new Fluoride analyzer can be identified staff will move forward with replacement of the analyzers and feed system components should the decision be made to continue Fluoride addition. Staff has reached out and inquired about the new Hach Fluoride analyzers and received quotes for replacements. Due to the current equipment being obsolete, a total replacement of the feed system and its components is the best option to continue with the addition of Fluoride to the water system safely.
Staff has communicated with FDEP regarding the City’s Fluoride add. If the City ultimately determines to permanently halt adding fluoride, all is needed is a written notification to FDEP and we will not be required to modify the operational permit or provide additional sampling.
