Iron and Manganese Monitoring with Hydrant Flushing and Testing

The City of Creedmoor recently engaged Pace Labs to conduct random water sampling across the SGWASA/City of Creedmoor service area. The initial focus was on evaluating Disinfection By-Products (DBPs), which are chemical compounds formed when disinfectants like chlorine or chloramine react with natural organic matter in water.

Common DBPs include Trihalomethanes (THMs), Haloacetic Acids (HAAs), and Chlorite and Bromate. Pace Labs’ analysis confirmed that all DBP levels were within the Maximum Contaminant Levels (MCLs) established under the Safe Drinking Water Act.

In April of 2025, the Creedmoor Board of Commissioners directed a shift in testing priorities, from DBPs to a broader range of water quality indicators. Subsequent testing revealed that Iron and Manganese levels at certain locations exceeded the EPA’s Secondary Maximum Contaminant Levels (SMCLs). These SMCLs are non-enforceable guidelines intended to address aesthetic concerns such as taste, odor, and discoloration, rather than health risks.

Both Iron and Manganese are naturally occurring minerals that enter the water supply through contact with soil and rock. While not considered health hazards at typical concentrations, elevated levels can cause:

• Metallic taste

• Discoloration of water

• Staining of fixtures and laundry

According to SGWASA’s 2024 Consumer Confidence Report, the levels of these minerals leaving the water treatment plant were:

Iron: 0.118 mg/L

Manganese: 0.012 mg/L

These values are well below the SMCL thresholds.

SGWASA’s Response SGWASA has initiated a comprehensive flushing and testing program across the entire service area, including the same locations tested by Pace Labs. Our internal results generally indicate lower concentrations of Iron and Manganese than those reported by Pace Labs. Test results are included for your review.

To further investigate, SGWASA is collaborating with engineering consultants

Hazen and Sawyer to:

Identify potential sources of elevated Iron and Manganese in the water distribution system, including the impact of aging infrastructure (some pipes date back to the 1930's and 1940's).

Recommended strategies to reduce these concentrations and improve water quality.

Next Steps

With the addition of two Utility Maintenance Mechanics, SGWASA is developing a new, system-wide flushing and maintenance program to be launched in FY25-26.

This initiative will include:

Routine hydrant flushing and water quality testing

Hydrant maintenance, repair and painting

Water valve exercising and system optimization

SGWASA remains committed to ensuring high water quality and addressing localized issues related to Iron and Manganese.

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Posted 9/11/25 by the South Granville Water and Sewer Authority 

Scott N. Schroyer, Executive Director

Chris Summerlin, Assistant Executive Director

Krystle Lee, PIO/Board Secretary/Webmaster

klee@sgwasa.org

(919) 575-3367