Redevelopment of Clogged Recharge Wells

Field conditions were reproduced in the laboratory in order to investigate redevelopment techniques. Segmental perspex models were recharged with water of controlled quality and temperature containing different types of suspended solids of known size. Both graveland nongravel‐packed recharge wells were tested. It was found that the most efficient method of redeveloping a clogged recharge well was by multiple reversals of flow direction (i.e., pumping and recharging the aquifer). A purely intermittent pumping action following the first reversal of flow had practically no increased beneficial effect on the recovery recharge rates. It was also concluded that neither increasing the driving head under which the reversal is carried out nor increasing the duration of the reversal of flow has a marked beneficial effect. Nongravel‐packed wells were easier to redevelop than gravel‐packed ones and the use of backwashing tubes in the gravel pack did not prove highly successful in restoring the well efficiency.