A Protected Source in a Vulnerable State
Central Arkansas Water (CAW) serves approximately 500,000 people in the Little Rock metropolitan area, drawing primarily from Lake Maumelle — a 8,900-acre reservoir in the Ouachita Mountain foothills west of the city — and supplemented by Lake Winona.
Lake Maumelle benefits from a relatively undeveloped watershed. CAW owns or manages thousands of acres of buffer land around the reservoir, and development restrictions have kept the watershed largely forested. This protection pays off in water quality — the source water is consistently clean, with low turbidity and moderate organic matter.
The treatment plant at Lake Maumelle uses conventional treatment (coagulation, sedimentation, filtration) followed by chloramine disinfection and corrosion control. The finished water meets all EPA standards and is generally well-received by customers.
But the story of water in Arkansas extends far beyond Little Rock’s protected reservoir.
Arkansas’s Groundwater Crisis
While Little Rock drinks surface water, much of Arkansas depends on groundwater — and the state’s aquifers are in serious trouble.
The Mississippi River Valley Alluvial Aquifer — the same system Memphis depends on — (the “Delta aquifer”) underlies eastern Arkansas’s agricultural heartland. Decades of intensive irrigation for rice, soybeans, and cotton have drawn down water levels dramatically — in some areas, groundwater levels have dropped more than 100 feet since the 1950s.
The Sparta Aquifer, which supplies many communities in southern and eastern Arkansas, is similarly stressed. Some cities have had to seek alternative water sources as wells produce less water or run dry entirely.
This doesn’t directly affect Little Rock’s supply (the city uses surface water), but it shapes the statewide water conversation and drives competition for surface water resources that Little Rock depends on.
Watershed Development Pressure
Lake Maumelle’s protected watershed faces growing pressure from suburban development. The western suburbs of Little Rock and communities in Pulaski and Saline counties are expanding toward the reservoir, bringing:
- Stormwater runoff from roads, parking lots, and residential development
- Septic system effluent from areas without centralized sewer service
- Construction sediment that can increase turbidity in the reservoir
- Nutrient loading from lawn fertilizer and pet waste
CAW has fought to maintain watershed protections, including working with local governments on zoning and development standards. The utility funds a watershed management program that monitors water quality, conducts land conservation, and educates the public.
The tension between growth and water source protection is a defining issue for Little Rock’s long-term water security.
Disinfection Byproducts
Like many utilities using surface water with moderate organic content, CAW manages disinfection byproduct formation. The switch from free chlorine to chloramine for secondary disinfection helped reduce TTHM and HAA5 levels, and the utility generally maintains compliance with EPA limits.
Seasonal variations in reservoir organic matter — higher during warm months when algal activity increases — can affect DBP precursor levels. CAW adjusts treatment accordingly and monitors DBP levels throughout the distribution system.
Lead in Older Neighborhoods
Little Rock’s downtown core and surrounding neighborhoods — including the Heights, Hillcrest, Stifft Station, and Capitol View — have housing stock from the early-to-mid 1900s with potential lead service lines and lead solder in interior plumbing.
CAW uses optimized corrosion control (pH and alkalinity adjustment) to minimize lead leaching and has met the EPA’s action level in system-wide testing. The utility is conducting lead service line inventory work as required by the revised Lead and Copper Rule.
For individual homeowners in older houses, the risk of lead exposure from plumbing remains — particularly when water sits stagnant in pipes for hours.
PFAS: Early Data
PFAS monitoring in Arkansas has been less extensive than in some states, but the EPA’s UCMR 5 program and the 2024 PFAS rule are bringing new data. Little Rock’s potential PFAS sources include Little Rock Air Force Base (Jacksonville, AR), the Little Rock National Airport, and industrial facilities in the metro area.
CAW is monitoring for PFAS compounds in its source and treated water. Arkansas has not adopted state-level PFAS drinking water standards, relying on federal regulations.
What Residents Can Do
- Review CAW’s annual Water Quality Report for current contaminant data
- For older homes, flush the tap for 30 seconds to 2 minutes before drinking, especially in the morning
- Consider a certified water filter — NSF/ANSI 53 for lead, activated carbon for taste and DBPs, NSF P473 for PFAS
- If you’re on a private well in central Arkansas, test annually for bacteria, nitrates, and iron. Eastern Arkansas well owners should also monitor water levels
- Support watershed protection — Lake Maumelle’s water quality depends on keeping development pressure in check
If you’re concerned about your water quality, a certified water treatment professional can test your water and recommend solutions appropriate for your specific situation.
Sources
- Central Arkansas Water, Annual Water Quality Reports
- Arkansas Natural Resources Commission, Groundwater Studies
- USGS, Arkansas Water Science Center, Aquifer Depletion Studies
- EPA SDWIS, CAW compliance records
- Environmental Working Group, Tap Water Database
- Pulaski County, Watershed Protection Ordinances