Treatment Process

The Cary/Apex Water Treatment Plant uses a relatively new process with special concrete treatment basins called Super-Pulsator Flocculator Clarifiers for removing particles from the water. Each Super-Pulsator Clarifier can treat up to 8 million gallons of water a day. These devices save money because they require less space than conventional sedimentation basins.

The basins use a vacuum chamber for pulsing action as water flows upward, becoming clearer as larger particles settle. Pulsing prevents particles from settling completely, and over time these particles form a blanket that helps filter water as it flows upward through the basins. The plant also has 16 multi-media filters that remove finer particles. Ozone is used to disinfect, remove organics, and control taste and odor. Ammonia and chlorine are added for final disinfection except each March when ammonia is suspended.

Fluoride is added as the federally recommended level of 0.7 parts per million.

Water Quality Testing and Reports

Annually, the Town takes tens of thousands of water samples from all parts of the water distribution system and tests these to ensure drinking water meets or surpasses all state and federal regulatory standards. Results of our testing, along with additional water quality information, can be found in the Town’s 2019 Drinking Water Quality Report provided for water customers annually as required by the U.S. Environmental Protection Agency. The report summarizes test results, health effects information and other important information about Town water programs. 

Archived Annual Drinking Water Quality Reports

2018 Water Quality Report
2017 Water Quality Report
2016 Water Quality Report
2015 Water Quality Report
2014 Water Quality Report
2013 Water Quality Report
2012 Water Quality Report

In addition, water customers may view the Water Quality Testing Summary, a comprehensive laboratory report containing test results for all parameters for finished water from the Cary/Apex Water Treatment Facility and distribution system.

While customers may periodically receive solicitations offering various services related to their water quality like private testing, Cary is not affiliated with these companies or their offerings. Cary utility customers should weigh the merits of the program, but are under no obligation or requirement to participate.


safewaterCary has received the Directors Award of recognition from the Partnership for Safe Drinking Water, an association of water utilities and government, for going far beyond federal requirements in an effort to achieve excellence in water quality.


The Partnership for Safe Water

American Water Works Association

U.S. Environmental Protection Agency – Ground and Drinking Water

NC Department of Environmental Quality