Contaminated land Our Contaminated Land Strategy details how we will deal with contaminated land in the city. Private water supplies and distribution In Colchester, a private water supply is any supply that is not provided by Veolia, Essex and Suffolk Water or Anglian Water. The source of water may be from a well, borehole or spring. Report a sewer, septic tank or cesspool problem We can take action to investigate and resolve problems with spillage, overflow or odour. Report flooding or a drainage problem You can report a flood on a highway to Essex Council Council or flooding of rivers, streams and coastal areas to the Environment Agency. Report discharge into a ditch or watercourse You can report pollution discharging into ditches and watercourses to the Environment Agency incident hotline. West Mersea beach and bathing water West Mersea has had a 'Good' or 'Excellent' standard of bathing water almost every year since 1995. Oil tank safety checks It is your responsibility to keep your domestic oil storage tank safe.