Annual Water Quality Information
The Cobb County-Marietta Water Authority is proud to supply our wholesale customers with safe, high-quality drinking water that surpasses all requirements of the U.S. Environmental Protection Agency (EPA), and the State of Georgia Environmental Protection Division (EPD).
CCMWA’s Simmons Microbiological Laboratory is certified by the State of Georgia to test for Total Coliform and E. coli. The below information is a summary of testing performed in 2023.
Commonly Requested Parameters:
| Parameters | Quarles WTP mg/L Average | Wyckoff WTP mg/L Average | Maximum Limit MCL mg/L | Aesthetic Standards SMCL mg/L | EPA Limit Met by CCMWA? | Sources of Parameter in Drinking Water | Frequency of Test |
| Alkalinity | 22.7 | 27.1 | No EPA Limit | No EPA Limit | N/A | Natural from rock and soils; addition from drinking water treatment | Hourly |
| Calcium | 10.4 | 10.9 | No EPA Limit | No EPA Limit | N/A | Natural dissolution from rocks | Biweekly |
| Hardness | 32.2 | 34.5 | No EPA Limit | No EPA Limit | N/A | Natural dissolution from rocks | Biweekly |
| pH | 7.8 | 7.8 | No EPA Limit | 6.5-8.5 | Yes | Natural sources; addition from drinking water treatment | Hourly |
| Fluoride | 0.73 | 0.7 | 4.0 | 2.0 | Yes | Erosion of natural deposits; water additive which promotes strong teeth; discharge from fertilizer and aluminum factories | Annually/ 3 times daily |
Understanding Our Parameters:
The above chart displays the results of our annual testing. To ensure understanding, please review the below terminology and definitions:
- MCL- Maximum Contaminant Level - The highest level of a contaminant that is allowed in drinking water. MCLs are set as close to the MCLG (see below) as feasible using the available treatment technology. These are enforceable standards.
- MCLG- Maximum Contaminant Level Goal - The level of a contaminant in drinking water below which there is no known or expected risk to health. MCLGs allow for a margin of safety and are non-enforceable public health goals.
- Mg/L- Milligrams per Liter
- Ppm- Parts per million; a part per million corresponds to one second in roughly 11.5 days.
For more information about water quality parameters, click here.