Clarity is arriving in the search for answers to chronic issues with water in Port St. Joe.
During Tuesday’s regular bi-monthly meeting of the City Commission an engineer from Florida Rural Water Association presented findings from a pilot study that revealed promise in a treatment option that could reduce costs and address ongoing discoloration issues.
The pilot study was performed by FRWA, a non-profit trade association for water and wastewater utilities, using hydrated lime, a liquid form of lime, as part of the treatment protocol.
The study was approved by the Florida Department of Environmental Protection.
The results of the study showed using lime to replace caustic soda would cut costs by roughly two-thirds, create water more easily treated for consumption and cause no damage to the microfiltration system that is the heart of the city’s four-year-old water plant.
“It is effective, it will work and we are recommending lime,” said Sterling Carroll with FRWA.
Lime is typically used in water systems using well water and Carroll said the lime softening agent used for years in Port St. Joe was likely the culprit in ongoing discoloration issues since the new plant opened.
Over the years, he said, that lime agent ultimately and naturally turns into calcium in pipes.
When the city switched to the more caustic surface water as a source and changed treatment protocols accordingly, those calcium deposits were essentially scaled off the inside of pipes causing discoloration.
“The problem you’ve been having is that after years of lime softening it has turned to calcium,” Carroll said, adding that the results to hot water heaters, sinks, bathtubs are, and have been, evident.
“The discolored water would be a natural thing. Your consultant should have told you about that from the beginning, maybe they did.”
The biggest concern with the lime, from the outset of the pilot study, was impact to the microfiltration system, not only critical to the water plant but also extremely expensive to replace or repair, Carroll said.
Siemens, the company that manufactures the system, is, Carroll said, understandably resistant to any changes to its recommended treatment protocols and it required looking outside Florida to find other municipal water plants using lime in the treatment protocol with microfiltration systems.
Those plants, Carroll added, all said the process works.
“We found no problems with the microfilters,” Carroll said.
The next step, which commissioners unanimously took Tuesday night, is to go out for bids on a tank and system for introducing lime into the treatment process.
The pilot study used a temporary and isolated injection system, Carroll said, and was not suitable for wider use, even in the short term.
The estimated cost of just under $200,000 for a new lime injection system would pay for itself in two to three years, commissioners noted, when factoring that the cost of a tanker of lime is $3,335 compared to $10,000 for a tanker of caustic soda.
Plant manager Larry McLamma said the plant uses roughly one tanker of soda per month and Carroll said the amount of lime that would be used would be equivalent.
That is an estimated difference of roughly $80,000 a year.
“It looks like we are on the way to getting this four-year-old problem solved,” said Commissioner Rex Buzzett.
In addition to the lime pilot study, McLamma and his crew have also taken up pre-treatment with chlorine which has greatly improved levels of manganese – the source of water the color of ice tea or darker – in the water.