Selbyville water report shows no violations, but high numbers

Date Published: 
Aug. 4, 2017

All central water systems are required to produce an annual report under the Safe Drinking Water Act. It’s meant to tell people where water comes from, what it contains and how it stacks up against regulatory standards. The Town of Selbyville’s water system report was recently released for the 2016 year.

“This report is a snapshot of last year’s water quality,” the report states. “During 2016, we conducted tests for over 80 contaminants. We detected 10 of those contaminants and found all but one were below the levels of EPA standards.”

Selbyville’s groundwater comes from the Columbia Aquifer. It has a moderate susceptibility to pathogens; a very high susceptibility to petroleum hydrocarbons; and a high susceptibility to nutrients, pesticides, PCBs, other organic compounds, metals and other inorganic compounds.

Gasoline additive MTBE (methyl tert-butyl ether) averaged about 1.78 ppb. The goal is zero, although the State allows up to 10 ppb.

Water quality has improved since the Town’s new water plant has come online this summer. In fact, the aeration towers are working so well that MTBE is barely being detected, said Town Administrator Stacey Long.

“These aerators are doing exactly what they’re designed to do,” Long said. “We’re really pleased with the outcome. We’re pleased with how it’s rectified the MTBE contaminant. It also helps with the TTHM. It’s a win-win.”

Meanwhile, the Town regularly empties its water pipes to reduce total trihalomethanes (TTHMs), which form when chlorine disinfectants sit for too long and react with organics in the pipes.

The Office of Drinking Water put Selbyville on notice in the spring of 2016 for high TTHM averages. However, the 2016 water quality report doesn’t consider the 113 ppb a violation because the State has no required goal, although 80 ppb is the preferred maximum.

To keep those numbers down, Selbyville installed an automatic flusher “on a yard hydrant out at the very end, where we were having high readings,” Long said. “We’re flushing the water out there more frequently. Those TTHMs are well within standard, or well below limit.”

Another chlorine byproduct, haloacetic acids, also has no State requirement, but Selbyville averaged 33 ppb out of a preferred 60 ppb.

Chloride and sulfate were only a tenth of their preferred maximum. Iron was nonexistent, and nickel was nearly zero. Manganese and naphthalene were only a fifth of their allowed maximum, while total dissolved solids were at 50 percent of the maximum.

The water’s Ph was slightly alkaline, measuring 8.4 out of a maximum 8.5. Hardness was ranked at 12 parts per million. Sodium measured at 64.2 ppm, and alkalinity was 85.2 ppm. Fluoride averaged 1.2 ppm out of 2.0 ppm.

The Annual Drinking Water Quality Report for 2016 is available online at www.selbyville.delaware.gov/water-department and www.DelawareSourceWater.org.

For more information, the public may contact Selbyville Town Hall at (302) 436-8314 or Water Department at (302) 436-8349. They may also attend town council meetings, typically held on the first Monday of each month at 7 p.m. at town hall.