ABSTRACT
Anglian Water Services supply 1263 Ml of potable water per day to 3.9 million customers spread over an area of 27500 sq. kms in eastern England which includes up to a 100 Ml/d export to neighbouring water companies. The company are currently examining the feasibility of using aquifer storage and recovery (ASR) to supplement available groundwater resources. This paper presents the results of a pilot scale ASR test which was conducted at an Anglian Water site to the north of Colchester in the county of Essex, England. The test was based upon the injection and recovery of 2800 m3 of treated water. The target aquifer was the semi-confined Chalk. The results of the test confirm that treated water can be injected into the Chalk at high rates but that the rate of re-abstraction will be limited by the large draw downs which were experienced. The test also confirms that diffusion exchange processes within the Chalk and interaction between the injected water and the overlying Tertiary strata, are both likely to impact on the injected/stored water quality. To further investigate the potential for developing an ASR scheme at the site, larger scale testing is being conducted.
