More news...

Jul 6, 2018
Category: Drought
Posted by: Kathryn

With this hot weather our water use goes up; this leaves less water available for the Chess.

May 3, 2018
Category: Abstraction
Posted by: Kathryn

With an ever-growing demand for drinking water and increasingly extreme weather events, how do we get the water we need without causing even more harm to our rivers?

May 2, 2018
Category: Drought
Posted by: Kathryn

Our riverfly monitors are back out in the centre of Chesham checking for life in the Chess now that flow has returned.

Mar 24, 2018
Category: HS2
Posted by: Kathryn

A public meeting with HS2 and the Environment Agency looked at the risks posed by tunnelling to the groundwater and rivers of the Chess and Misbourne Valleys.

Latest News

Raw Sewage in the Chess

Jan 29, 2013

Category: Pollution
Posted by: Kathryn

A sanitary towel found in the River Chess

One of several items of sewage detritus found in the River Chess over the last few days

We are saddened to report that there was a discharge of sewage into the River Chess on Sunday 27th January from the Chesham Sewage Treatment Works (STW) operated by Thames Water.

In April 2012, Thames Water doubled the storm water holding tanks at the STW and we had hoped that we had seen the last of these sewage discharges. During what was a very wet summer, the STW coped with the very high levels of throughput and no discharges occurred. This gave us the encouragement to embark on a number of projects to improve water flows, fish migration and fish numbers and to start an eel monitoring programme with the Zoological Society of London. We have also carried out a habitat enhancement project at Rickmansworth and are planning other projects of this type in 2013. Clean water is essential to the success of these projects, so it is important that we resolve this discharge issue permanently.

Thames Water has given us this explanation of events: "The discharge from the storm tanks was due to the very heavy rainfall overnight on Saturday plus the melting snow....The incoming flow at the works exceeded the capacity of the treatment process and filled the storm holding tanks as designed. When these became full, the tanks discharged settled dilute sewage, which combines with the treated final effluent to the river."

We visited our monthly fly monitoring site at Blackwell Hall on the 28th January to take an invertebrate sample to check on the effect of the sewage discharge. This site is just below the sewage outfall pipe. There were no mayfly nymphs (Ephemera danica) which are normally found at this site. These are one of the least tolerant invertebrates and react badly to polluted water. We will revisit the site in the next few days. The Environment Agency is aware of the problem and are involved in monitoring developments.

The other concern is the large amount of sewage detritus, such as sanitary towels and disposable nappy liners, being found in the river. Two items were snagged immediately below the outfall pipe and could only have come from the sewage works. Some small fragments turned up in the fly monitoring sample. This is an on-going problem that is not just associated with this sewage discharge. Three items turned up in the sluice pool at Dodd's Mill on Friday 25th January; this is two miles downstream of the outfall pipe. We would urge the public not to put any items such as sanitary towels, tampons and "flushable" wipes down the toilet, as these can all end up in the river.

The water was running clean from the outfall by the morning of Monday 28th January, but as more heavy rain is expected over the next few days we have concerns that further discharges could occur. Although legal and permitted by the STW licence, such discharges are undesirable in any river, let alone a chalk river of such high quality as the River Chess. We appreciate that Thames Water staff did what could be done to minimise the volume of discharge, but a permanent solution is needed.

We are arranging to meet with Thames Water to see what can be done to resolve this discharge problem and the other issue of sewage detritus.