음용수 저장 탱크 안에 고여 있는 물이 층화, 생물막, 과도한 소독부산물, 살균제 잔류손실 등의 문제를 일으킬 수 있다. 분배 시스템 저장소 내의 얼음 생성 또한 겨울 동안 추운 북부 기후에 있는 물 시설들에겐 또 다른 도전과제이다.

얇은 얼음 막은 장기적인 빙점 아래 기온 동안 저장 탱크 표면에서 종종 형성되고, 철 탱크의 접합선(seams)은 얼음이 형성된 동안 팽창해 구조적인 손상 및 물 부족의 원인이 될 수 있다. 게다가 유입과 유출에 의한 거대한 얼음 조각의 수직운동은 탱크에 더 큰 손상을 가져올 수 있다.

 

 

 

Quiescent waters in potable water storage tanks can cause problems such as thermal stratification, biofilms, excessive disinfection byproducts, and disinfectant residual loss. Ice formation in distribution-system reservoirs is also another challenge for water utilities in northern climates during winters.

 

Thick layers of ice often form at the surface in storage tanks during prolonged periods of subfreezing weather, and the seams of steel tanks can expand during ice formation, causing structural damage and water leakage. Further, the vertical movement of large ice chunks with inflows and outflows may further damage the tanks.

 

The rural community of Lyons in Central Michigan, for example, faced problems of icing every year since its potable water tank was built in 1972. According to Susan Craft, superintendent of the Department of Public Works, ice damage eradicated the tank's cathodic protection.

 

During the process of renovating and updating the single pedestal tank, Craft consulted with Dixon Engineering in Lake Odessa, Mich., on a solution to the problem and in November 2012 installed a GridBee® GS-12 mixer from Medora Corporation. She reported that there was no ice buildup in the tank the first winter and that the effects of year-round mixing have significantly improved chlorine residual.

 

[출처 = Water World / 2014년 12월 10일]