▁on ▁the ▁Ch el mer ▁and ▁Ter , ▁so ▁that ▁water ▁from ▁either ▁or ▁both ▁could ▁be ▁fed ▁into ▁a ▁concrete ▁pipeline ▁which ▁was ▁ ▁in ▁diameter ▁and ▁ ▁long . ▁The ▁water ▁flow ed ▁by ▁gravity ▁along ▁the ▁pipeline ▁to ▁two ▁sed iment ation ▁res er voir s ▁each ▁covering ▁ ▁and ▁capable ▁of ▁holding ▁. ▁Water ▁from ▁the ▁Black water ▁int ake ▁at ▁Lang ford ▁Mill ▁is ▁p ump ed ▁to ▁the ▁sed iment ation ▁res er voir s . ▁From ▁there ▁the ▁water ▁flows ▁by ▁gravity ▁to ▁the ▁Lang ford ▁p ump ing ▁station . ▁In ▁order ▁to ▁maintain ▁the ▁quality ▁of ▁the ▁water , ▁eff lu ent ▁dis charg ed ▁from ▁the ▁Ch el ms ford ▁se w age ▁treatment ▁works ▁on ▁the ▁Ch el mer ▁and ▁the ▁With am ▁se w age ▁treatment ▁works ▁on ▁the ▁Black water ▁was ▁pip ed ▁to ▁new ▁out falls ▁below ▁the ▁int akes . ▁ ▁When ▁built , ▁the ▁Lang ford ▁p ump ing ▁station ▁contained ▁two ▁triple - exp ansion ▁steam ▁engines , ▁with ▁room ▁for ▁a ▁third , ▁which ▁was ▁fitted ▁in ▁ 1 9 3 1 . ▁There ▁were ▁used ▁in ▁pairs , ▁and ▁each ▁drove ▁a ▁low ▁lift ▁p ump ▁to ▁transfer ▁water ▁to ▁the ▁treatment ▁works , ▁and ▁a ▁high ▁lift ▁p ump ▁to ▁take ▁treated ▁water ▁and ▁p ump ▁it ▁along ▁a ▁ ▁cast ▁iron ▁pipe ▁to ▁South end . ▁The ▁pipe ▁crossed ▁below ▁the ▁River ▁Cr ouch ▁at ▁H ull bridge , ▁where ▁sh aft