Ahead of the five-yearly pricing review by Ofwat, the water industry watchdog, Goldman Sachs has been running the rule over the water companies, with mixed results.The US bank has reduced its price target for Northumbrian Water to 237p from 262p, and has a "sell" recommendation on the stock. It also rates Pennon a "sell" but has upped its price target for the stock from 435p to 503p.It is neutral on Severn Trent and has raised its target price for the shares to 1451p from 1322p. United Utilities also gets its price target lifted, to 549p from 527p.