Another week of stinky water ahead

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Portions of Peachtree City, Tyrone, the west side of Fayetteville and some unincorporated areas between Fayette’s two largest cities continue to report as late as press time on Tuesday that the foul tasting and smelling drinking water supplied by the Fayette County Water System is still flowing from their taps.

Fayette County Water System officials Tuesday said the water in the Crosstown plant has essentially been replaced though it will likely take several additional days, perhaps until early next week, to have the affected water run through the water system lines and the problem resolved.

A host of area residents over the weekend and into the beginning of the week were still reporting water that smells and tastes bad, with descriptions ranging from tasting and smelling like dirt or potting soil to tasting and smelling like lead or some other metal.

Residents in the affected areas said they have resorted to buying bottled water for the past two weeks while some restaurants are serving water that customers will not drink and others have posted signs saying they will be serving only bottled water until the problem is resolved.

Responding to requests by The Citizen, Fayette County Water System Assistant Director Russell Ray provided details about the source of the ongoing problem, the reason it continues to persist some two weeks later and the approach being used to eliminate the problem.

“Prior to the taste and odor problem, we were pumping two sources of water to the Crosstown plant — Lake Peachtree and Starr’s Mill (Pond).

“Lake Peachtree has a history of causing taste and odor in the past, but not in recent years. Starr’s Mill typically has high iron and manganese; however, it may have contributed to the taste and odor problem also.

“Earthy or grassy odors are typically associated with chemical compounds produced by certain types of algae. Algae were seen in Starr’s Mill Pond.

“We add copper sulfate to Lake Peachtree routinely to keep algae growth to a minimum; however, with the heavy rain events this year, nutrients washed into the streams and lakes may have caused more algae growth than normal.

“This, along with decaying organic matter from lake mixing caused by temperature changes (mentioned in earlier statements) are the sources of the taste and odor,” Ray said.

Ray noted the attempts to rectify the problem by shutting down intake from Lake Peachtree and Starr’s Mill Pond and, instead, using water from Lake Horton.

“As it became evident that powder activated carbon (PAC) treatment alone could not remove the taste and odor compounds, the decision was made to change the source water being treated at Crosstown. Lake Horton water is pumped to the South Fayette plant and there have been few if any taste and odor issues associated in the areas receiving water from south Fayette. We discontinued the use of Lake Peachtree and Starr’s Mill Sunday evening, May 5, and started pumping Lake Horton water to the Crosstown plant,” Ray said.

Ray described the process that required a number of days to mitigate, adding that the replacement of water from the Starr’s Mill Pond at the Crosstown plant with its higher naturally-occurring iron content with water from Lake Horton took approximately seven days to mitigate.

“Unfortunately, we could not see an immediate benefit by using Lake Horton water. The holding pond at the Crosstown plant holds approximately 25 million gallons. Treating water at a rate of 5 million gallons a day (mgd) has taken approximately five days to displace the water in the holding pond. The holding pond contained Starr’s Mill water with a higher iron concentration than Lake Horton,” said Ray. “The iron concentration in the raw water dropped consistently over the past seven days, indicating the holding pond water is now primarily water from Lake Horton.”

Ray said the improvement in the water source does not eliminate the problem. The hydraulic conditions in play at the Crosstown plant required several days to correct.

“With the source water issue improved, the remaining issue is to displace the treated water in the plant itself. There are several million gallons in the sedimentation basins, and approximately 5 million gallons held in two finished drinking water ‘clearwells’ that hold treated, potable water,” said Ray. “Each clearwell can hold 2 million gallons and 4 million gallons, respectively. Under standard flow conditions, at a treatment rate of 5 mgd, two days are needed to displace the water in the plant. However, splitting the flow between the two clearwells and mixing effects will cause the time for complete displacement to vary.

“The odor has diminished in both clearwells but is still detectable (more so in the 4 million gallon clearwell),” Ray continued. “Based on the hydraulic conditions described above (including the clearwells) it is taking 7-10 days to replace the water onsite at the Crosstown plant. Displacement of the water in the plant would have been faster during a higher demand period. However, demand has remained at or just above winter levels due to the frequent rain events this year. Flushing the water mains have helped keep the treatment plant in operation. But still at a rate that has prolonged the taste and odor problem.”

Ray in his comments noted that with the 7-10-day period at the Crosstown plant essentially completed, it will take several additional days, perhaps into early next week, to have water replaced in water lines running through Fayette County.

“We will continue to flush the water mains in order to treat the water at the highest rate possible. As the water improves at the Crosstown plant, it will gradually improve in the pipe system. This will take several additional days in some areas,” said Ray. “Complaint call volumes have gone down in the central part of the county, however, have remained heavy in the western area (of the county). Although our water distribution system is connected by a loop water line, all three clearwells feed to a different part of the county. As mentioned earlier, the south Fayette plant clearwell feeds the southern and eastern part of the county. The Crosstown 2 million gallon clearwell feeds the central part of the county and the 4 million gallon clearwell feeds the western part of the county.”

Ray in his comments also noted that the newly filled Lake McIntosh in west Fayette County has yet to be used as a drinking water source.

Last week, Water System Director Tony Parrott in response to complaints from area residents that began approximately two weeks ago said the concerns regarding a “musky” odor in the water was no reason for alarm. The problem is being resolved and the water is completely safe to drink, Parrott said.

“Upon receiving complaints, the water system immediately dispatched staff to investigate the situation,” Parrott said.

“It has been determined that the odor is due to a reaction from chlorine and the water from Lake Peachtree. The reaction was caused by a significant change in water temperature.”

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At The Citizen’s request, Russell Ray, Assistant Water System Director, on May 14 provided the following detailed timeline and explanation of the water problems:

“Prior to the taste and odor problem, we were pumping two sources of water to the Crosstown plant — Lake Peachtree and Starr’s Mill.

“Lake Peachtree has a history of causing taste and odor in the past, but not in recent years. Starr’s Mill typically has high iron and manganese; however, it may have contributed to the taste and odor problem also.

“Earthy or grassy odors are typically associated with chemical compounds produced by certain types of algae. Algae were seen in Starr’s Mill Pond.

“We add copper sulfate to Lake Peachtree routinely to keep algae growth to a minimum; however, with the heavy rain events this year, nutrients washed into the streams and lakes may have caused more algae growth than normal.

“This, along with decaying organic matter from lake mixing caused by temperature changes (mentioned in earlier statements) are the sources of the taste and odor.

“As it became evident that powder activated carbon (PAC) treatment alone could not remove the taste and odor compounds, the decision was made to change the source water being treated at Crosstown.

“Lake Horton water is pumped to the South Fayette plant and there have been few if any taste and odor issues associated in the areas receiving water from South Fayette.

“We discontinued the use of Lake Peachtree and Starr’s Mill Sunday evening, May 5, and started pumping Lake Horton water to the Crosstown plant. Unfortunately, we could not see an immediate benefit by using Lake Horton water.

“The holding pond at the Crosstown plant holds approximately 25 million gallons. Treating water at a rate of 5 million gallons a day (mgd) has taken approximately 5 days to displace the water in the holding pond.

“The holding pond contained Starr’s Mill water with a higher iron concentration than Lake Horton. The iron concentration in the raw water dropped consistently over the past seven days, indicating the holding pond water is now primarily water from Lake Horton.

“With the source water issue improved, the remaining issue is to displace the treated water in the plant itself.

“There are several million gallons in the sedimentation basins, and approximately 5 million gallons held in two finished drinking water clearwells. Each clearwell can hold 2 million gallons and 4 million gallons, respectively.

“Under plug flow conditions, at a treatment rate of 5 mgd, two days are needed to displace the water in the plant. However, splitting the flow between the two clearwells and mixing effects will cause the time for complete displacement to vary.

“The odor has diminished in both clearwells but is still detectable (more so in the 4 million gallon clearwell).

“Based on the hydraulic conditions described above (including the holding pond) it will take 7 to 10 days to replace the water onsite at the Crosstown plant [starting May 5].

“Displacement of the water in the plant would have been faster during a higher demand period. However, demand has remained at or just above winter levels due to the frequent rain events this year.

“Flushing the water mains have helped keep the treatment plant in operation. But still at a rate that has prolonged the taste and odor problem.

“We will continue to flush the water mains in order to treat the water at the highest rate possible. As the water improves at the Crosstown plant, it will gradually improve in the pipe system. This will take several additional days in some areas.

“Complaint call volumes have gone down in the central part of the county; however, [complaints] have remained heavy in the western area.

“Although our water distribution system is connected by a loop water line, all three clearwells feed to a different part of the county.

“As mentioned earlier, the South Fayette plant clearwell feeds the southern and eastern part of the county. The Crosstown 2 million gallon clearwell feeds the central part of the county and the 4 million gallon clearwell feeds the western part of the county.

“Chemicals used to treat the water at the Crosstown plant have not changed except for the addition of PAC to absorb taste and odor compounds.

“Alum is added for coagulation, lime for pH control, chlorine dioxide for iron and manganese reduction, polyphosphate for corrosion control, fluoride for dental health, and chlorine for disinfection.

“Lake McIntosh had not been used since [being] filled.

“Hopefully, the timeline above explains why some areas are still experiencing the taste and odor problem. As indicated, it will take several more days to improve in those areas.” — Russell Ray, Assistant Water System Director.