Ceramic UF Retrofit Saves Costs, Power, Labor and Water

Ceramic UF Retrofit Saves Costs, Power, Labor and Water

The Canyon Regional Water Authority (CRWA) in New Braunfels, Texas operates the Lake Dunlap Water Treatment Plant, which treats surface water from the Guadalupe River. The plant is licensed to provide wholesale drinking water to Texas retail water suppliers.

Although CRWA was operational, the plant was struggling with its polymeric UF system, making it increasingly difficult to ensure capacity and pass membrane integrity tests. Massive fiber breakage required constant manual intervention from plant operators, affecting the work environment and operating costs. The polymeric UF membranes needed frequent chemical cleanings to restore permeability, which caused membrane degradation and created systemic problems. Plant operators implemented longer backwashes, consuming a significant volume of water which led to an overall water recovery rate of 83.6%. CRWA was seeking a more resilient and robust system to address these issues.

After conducting pilot tests comparing the CM-151 and two different polyvinylidene fluoride (PVDF) membranes, the choice was clear —CRWA replaced all six of the existing polymeric UF systems with Nanostone’s ceramic UF membranes. The unique monolith design of the CM-151 increased the plant’s overall output to 14.4 MGD, making CRWA the largest potable water plant in Texas to employ ceramic membranes. Nanostone’s fiber-free ceramic membranes easily pass the daily integrity test without operator intervention and ensure the permeate water meets the rigorous quality standards for drinking water.

Implementation of the CM-151 modules in combination with optimizing the operating mode of the plant has increased the overall water recovery rate by 14.1%, which means less environmental impact from wasted water. Also, by switching the from cross-flow to dead-end filtration, CRWA was able to phase out the recirculation pumps, enabling a 50%reduction in power use for the plant. The drinking water being delivered to citizens of New Braunfels and the surrounding communities has significantly improved clarity, as is evidenced by permeate water turbidity low as 0.025 NTU compared with previous levels of 0.074 NTU. Thanks to all of these improvements, CRWA has experienced a significant reduction of downtime, labor, power and chemical use while saving water.