P2.3.1 Fence channel and tanks Turbidity. Abnormally Replace the to keep stock clear. high turbidity open Stock of water channel with access to quality. reaching pipes. the channel Ensure break pressure plant. and break Erect fence. tanks have a well-fitting tanks. High E. coli lid. Provide counts. suitable lid. Elevated chlorine demand. Evidence of stock having gained access to the channel. P2.3.2 Control land use Increasing Replace the practices in vicinity of quality. nutrient levels. open Surface open channel, channel with and Nutrients High E. coli particularly stock and (depending on counts. chemical application leaching of the nature of Elevated (fertiliser, pesticides). the fertiliser). chlorine water. Riparian margin demand. channel. P2.3.3 Ensure flow paths Algae of health Replace the prevent regions of slow quality. significance open moving water. present. channel with of water Flow. pipes. quality Develop maintenance Elevated Algal toxins (if caused by plan to remove biological levels of algae of increased growths. nutrients. concern are biological Control land use present). Visual activity in practices in the vicinity to evidence of Visual shallow, reduce nutrient input. biological inspection. warm open growths. channels. Temperature. Nutrients (nitrogen and phosphorus). P2.3.4 Carry out regular checks Turbidity. Abnormally Initiate of the state of the high turbidity checks. Collapse of channel, and after heavy of water the channel quality. Replace the rain, and shore up sides reaching sides. open as necessary. plant. channel with Fence channel and tanks High E. coli pipes. to keep stock clear. counts. Erect fence. Elevated chlorine demand. Evidence of stock having gained access to the channel. 2 The level of risk is high for those supplies using open channels and break-pressure tanks between the source and treatment plant, although treatment, including disinfection, should reduce the level of risk. Preventive measures Checking preventive measures Corrective action Causes What to Signs that action is needed
P2.3.1 Stock access to the channel and break tanks. Fence channel and tanks to keep stock clear. Ensure break pressure tanks have a well-fitting lid. Turbidity. quality. Abnormally high turbidity of water reaching plant. High E. coli counts. Elevated chlorine demand. Evidence of stock having gained access to the channel. Replace the open channel with pipes. Erect fence. Provide suitable lid. P2.3.2 Surface and leaching of water. Control land use practices in vicinity of open channel, particularly stock and chemical application (fertiliser, pesticides). Riparian margin channel. quality. Nutrients (depending on the nature of the fertiliser). Increasing nutrient levels. High E. coli counts. Elevated chlorine demand. Replace the open channel with P2.3.3 of water quality caused by increased biological activity in shallow, warm open channels. Ensure flow paths prevent regions of slow moving water. Develop maintenance plan to remove biological growths. Control land use practices in the vicinity to reduce nutrient input. quality. Flow. Algal toxins (if algae of concern are present). Visual inspection. Temperature. Nutrients (nitrogen and phosphorus). Algae of health significance present. Elevated levels of nutrients. Visual evidence of biological growths. Replace the open channel with pipes. P2.3.4 Collapse of the channel sides. Carry out regular checks of the state of the channel, and after heavy rain, and shore up sides as necessary. Fence channel and tanks to keep stock clear. Turbidity. quality. Abnormally high turbidity of water reaching plant. High E. coli counts. Elevated chlorine demand. Evidence of stock having gained access to the channel. Initiate checks. Replace the open channel with pipes. Erect fence. 2 The level of risk is high for those supplies using open channels and break-pressure tanks between the source and treatment plant, although treatment, including disinfection, should reduce the level of risk. Causes Preventive measures Checking preventive measures Corrective action What to Signs that action is needed
treatment-water-transmission-feb14-v2.docx