The 411 on H20
Aeration basins pumping oxygen into Darlington’s municipal wastewater.
Photos by Samantha Lyles
By Samantha Lyles, Staff Writer, slyles@newsandpress.net
Recent news stories about lead infiltration in the water supply of Flint, Michigan – and locally, the closing of a second Lamar well due to trace radium – have spurred some citizens to take a closer look at the quality of their water. Fortunately, the water supply in the City of Darlington is in good condition, clearing state and local inspections regularly with excellent results, but it takes a lot of work and extensive infrastructure to keep a municipal system running smoothly.
We took the nickel tour recently with Darlington Water and Sewer Department director Freddie Kinsaul and got an overview of how water travels from underground aquifers to our household taps, and what exactly happens to used water after it whooshes away down the drain.
The concrete maze where wastewater is chlorinated.
“We get all of our water from wells, and we have four wells,” says Kinsaul, noting locations off South Main Street, Pine Street, Auction Avenue, and in the woods off Hampton Street.
These four wells pull water from two sources, some from Black Creek but primarily from the Middendorf Aquifer, pumping it up from 350 to 600 feet underground. Kinsaul says that due to the soil composition in our area, the water has a significant amount of naturally occurring iron.
“The content varies based on the soil around each particular well, but you pick up some of whatever is in that soil – just like Lamar with the radium they’ve found, it’s a naturally occurring thing,” says Kinsaul.
Once these wells pump water up from the aquifer, it is pushed through a lime pressure filter and charcoal, sand, and gravel filters to adjust the pH to a neutral range of 6 to 7 (around the same acidity level as milk). Filtering removes about 95-percent of the iron, staves off pipe corrosion, and prevents build up of harmful trace elements – like lead – inside the pipes.
Testing of the well water is done two ways: water companies pay an annual fee for DHEC to come and pull random “strategic samples” from the wells for a yearly water quality report, and City of Darlington also contracts with licensed water engineering company Davis and Brown to handle daily operation and testing of the wells and the waste treatment plant.
“(The Davis and Brown) operators have a system now that they can pull up on their smartphones and constantly monitor pH, pressure, water levels, backflow – all of it in real time,” Kinsaul says, observing that this system allows for quick detection and remediation of problems in the water supply chain.
The South Main Street sewage lift station.
He also says this contract saves the city a lot of money, since DHEC requires certification and licensing of any person performing these duties. He estimates the city would need an additional three full-time, fully licensed water department employees to handle the duties they currently outsource.
“The average age of a certified water operator is 59; very few young people are getting into this line of work because it only pays about $10 an hour,” says Kinsaul.
After the pH is neutralized, the water is treated with fluoride (as it has been for the past 50 years) to help prevent tooth decay. Then it travels into the city’s distribution system, comprised of about 50 miles of underground water pipes, and into the various residential and commercial taps of some 3,200 municipal water customers.
When we have used that water for anything from bath time to dishwashing to toilet flushing, it enters the unloved yet absolutely essential sewer system. Sewer pipes flow by gravity down toward the nearest of 14 lift stations, where the water enters an underground tank and is forcibly pumped on to the next station, and the next, then is screened for large debris and pumped into two 16-foot deep aeration basins at Darlington’s Wastewater Treatment Plant on Society Hill Road.
One of the city’s four well heads.
“In the basins, oxygen is stirred into the water to make the bugs happy and hungry (they feed on harmful bacteria), and then it drains out onto large sand beds,” Kinsaul says.
Down and down the water goes again, filtering through about 15 feet of sand bed to an underdrain system. That feeds the water into a disinfection system – a sort of concrete maze where the water is exposed to more sunlight and chlorination. The water is then de-chlorinated to the point where microscopic water fleas – a sort of ‘canary in a coal mine’ biological testing system – can healthily exist and reproduce. Once the water meets the state-mandated criteria for cleanliness, it is released back into the wild, flowing into Black Creek.
Kinsaul says the water and sewer system in Darlington is in pretty good shape, considering the scarcity of federal and state grant money available for improvement projects where there are no public health issues or DHEC consent orders involved. He notes that during his time with the city, Water and Sewer has installed computerized water meters (which read and report on water usage every hour) for every residential customer, has refurbished all four wells, and is working (with $1.5 million in Renaissance Grant funds) to rehab water lines and storm drainage in South Darlington.
The historic floods of October, 2015 cast a lot of attention on storm drainage problems in many South Carolina towns, including Darlington. Kinsaul says that when small storm drains were dug many years ago, most cities never planned for the shrinking of green space and expansion of parking lots and non-absorbent surfaces. This proliferation of asphalt and concrete has overwhelmed once adequate storm drains, leaving ponds across streets and virtual lakes on front lawns.
Kinsaul says that, unfortunately, storm drainage ranks low on the priority list for granting agencies, and digging out and upgrading these drains is prohibitively expensive. For example, he notes that the intersection of Broad Street and South Main Street – a regular flood zone – has a small storm drain buried 15 feet below street level, and it would cost an estimated $5 million to $7 million to remedy the problem.
Darlington’s current water and sewer rates place the city in the bottom third of billing statewide. City manager Howard Garland says that while Darlington has not increased billing rates since 2013, a rate increase might be coming within the next year to help fund additional needed improvements and to remain competitive for state and federal grants.
