City of Durham

Durham water management officials utilize advanced modeling to determine sustainable water yields from the city's two primary lakes. After accounting for the severe drought conditions of 2007-2008 and implementing a 20% safety buffer, these sources reliably produce 27.9 MGD (million gallons per day).

The city is actively developing plans to incorporate two additional water sources - Michael Jordan Lake and Teer Quarry - to meet current and future demand. Since 2002, Jordan Lake has provided supplemental water for Durham through Cary's water system, with an initial allocation of approximately 10 MGD. Following the 2007-2008 drought, Durham secured an additional 6.5 MGD allocation to ensure water supply through 2060, approved by the N.C. Environmental Management Commission in 2017.

Durham is collaborating with neighboring water agencies to establish direct water transport from Jordan Lake into the municipal system. Teer Quarry first served as an emergency water supply during the height of the 2007-2008 drought. After purchasing the abandoned quarry in 2004, the city is now planning permanent facilities to enable quarry refilling from multiple sources during normal conditions, creating a reliable emergency water reserve.

Water flows from Durham's two source lakes to its Williams and Brown treatment plants through gravity flow, hydropower and electrical systems. On-site reservoirs at each facility maintain a two to three-day supply to stabilize distribution. In 2017, these plants provided 25.5 MGD to approximately 275,000 residents in the service area.

The Williams Water Treatment Plant on Hillandale Road (built 1917) has undergone several upgrades and now offers 22 MGD capacity. The Brown Water Treatment Plant on Infinity Road (completed 1977) has a 30 MGD capacity. Major renovations began at both facilities in 2017 and continue today.

Both plants employ conventional water treatment processes: coagulation (mixing caustic and ferric sulfate with source water), flocculation (gentle mixing allowing impurities to bond), sedimentation (removal of heavy particles), chlorine disinfection, filtration through sand and anthracite, and addition of phosphate (preventing pipe corrosion) and fluoride (dental health). The final stage adds chloramines as a disinfectant.

Durham has added fluoride to municipal water since 1957 to promote dental health. While state regulations previously required a concentration of 1.0 mg/l, updated guidance from the EPA and CDC in 2011 determined that dental benefits could be maintained at lower levels. North Carolina now allows water systems to reduce fluoride target levels to 0.7 mg/l, a change Durham implemented immediately upon approval. Public health experts continue to support fluoride addition as an important safeguard for dental health.

Frequently Asked Questions

What causes white or colored deposits on dishes and faucets?
These deposits are typically calcium carbonate, commonly known as limescale. The amount of calcium in water determines its "hardness." Vinegar cleaning can help dissolve these deposits. Using commercial water conditioners, liquid detergents, or the "air-dry" setting on dishwashers can reduce calcium carbonate buildup.

Are hard water deposits harmful to health?
Water hardness and resulting deposits pose no health concerns and may actually offer health benefits. The municipal system does not specifically treat for water hardness that might cause these deposits.

What level of hardness is in Durham's water?
The hardness ranges from 2 to 18 grains per gallon (gpg) throughout the system.

Why does my water appear cloudy when first dispensed?
Cloudy or milky appearance typically results from trapped air bubbles in the water. Simply allow the water to stand for a few minutes—the air will dissipate, leaving clear water.

Why is chlorine added to municipal water?
Chlorine serves as a disinfectant to protect public health by eliminating harmful organisms like bacteria and viruses during the treatment process.

How can I remove chlorine taste or odor from my water?
Try these methods:

• Store water in an uncovered glass container in the refrigerator overnight
• Bring water to a rolling boil for 5 minutes, then allow to cool
• Add a slice of lemon or a few drops of lemon juice to your glass

Will home treatment devices remove chlorine?
Some home filtration systems effectively remove chlorine. Once chlorine is removed, treat the water like any other beverage and consume promptly. Follow manufacturer's maintenance instructions to ensure continued water quality.