Sheeps Green Bathing Waters

Overview

Bathing water designation

Bathing waters are designated at locations where an interest group or owner of a potential bathing water has applied to Defra and been successful in getting the water designated as a bathing water. That location will be tested by us during the bathing water season and given a classification. Designation does not necessarily mean that the site meets water quality standards or is safe to swim in.

Bathing water season

The Bathing Water Regulations 2013 set out the bathing water season, which runs from 15 May to 30 September inclusive each year. We are responsible for sampling for two types of bacteria at designated bathing waters during the season. Sampling must start just before the season and include some weekend and bank holiday samples, when the largest number of bathers are often present.

When and how we sample

The legislation dictates that we must set a sampling program before the beginning of the season and stick to it as much as possible, taking each water sample at 30cm depth after wading into one metre of water.  This sample must then be analysed within 4 hours of being taken, or within 24 hours if refrigerated (our vans are refrigerated).

The results are then available 2-5 days later as the bacteria have to be plated up and grown before being counted. There is a set protocol for the sampling, including sterile bottles and aseptic techniques.

What we sample for

We analyse samples by set protocol for Escherichia Coli (E.C) and Intestinal Enterococci (I.E), two bacteria found in the gut of many animals such as humans, birds, dogs, and seals. These are used as faecal indicator organisms for other pathogens such as viruses.

Classification of bathing water

The bathing water bacterial counts taken over the last 4 years (excluding 2020 as the number of samples taken were impacted by Covid) are put through a complicated calculation using log10 means and standard deviations, which is set out in the legislation.  The resulting figure is then compared with the table below to give the classification.

NB. If a beach is ‘poor’ for 5 years then it is de-designated.

Origin of the bacteria

I.E. and E.C. are often from the faeces of a human or other animal including birds, dogs, seals, cows and pigs. They can be washed in from various sources:

• roofs (bird faeces)
• pavements or roads through surface water systems during rainfall
• misconnections from homes or businesses into the surface water
• issues with overflowing sewers or consented overflows
• agricultural runoff
• washed in at high tide after being deposited on beaches by animals defaecating
• deposited directly into the sea by birds or seals

Rivers often run through both urban and agricultural areas, which can potentially affect water quality. There may also be combined sewer overflows, emergency overflows (from sewage pumping stations) and surface water outfalls within the river catchment that can adversely impact the water quality.

Where to find out more about bathing water quality

The Swimfo site Bathing water quality (data.gov.uk) contains lots of useful information about bathing water quality – you can see all the data through the years with maps and details of investigations. If there is a known relevant ongoing pollution incident this will also be flagged on this site.

Pollution Risk Forecasting

There are some bathing waters in England where we know water quality can be affected by factors such as rain, tide, or wind that we can measure and use to make a daily forecast of quality.

At these sites, we make active water quality forecasts called Pollution Risk Forecasts (PRF) if factors that have previously been associated with reduced quality re-occur. This warns the public of a risk of reduced water quality to give an informed choice of where and when to bathe. It is not warning of an actual pollution incident occurring.

It is important to recognise these forecasts are not absolute and that these are just a means to flag higher risk days than the annual classification average. 

We make PRFs each day at 08:30 and post on Swimfo shortly afterwards. These are our best estimate of the risk, specific to each bathing water for that day.

In summary, we expect people to make their own decisions on what is an acceptable risk to them and will provide PRFs to help them make this decision. Additional information can be found at Swim healthy - GOV.UK (www.gov.uk)

Sheeps Green bathing water area

The River Cam flows through the city of Cambridge, it is popular for punting, canoeing and rowing. There is significant growth around the Cambridge conurbation. Elsewhere the catchment is mainly rural. 

Sheep's Green is located on the west bank of the River Cam in Cambridge. It is within the Sheep's Green and Coe Fen Local Nature Reserve.

Map shows location of bathing water site on River Cam.

Why are the water quality samples poor at Sheeps Green?

We have started investigating impacts on the bathing water in the area. Our focus is on identifying and minimising the human impacts to the environment such as from sewage releases and agricultural run-off.

What we are doing to improve the water quality at Sheeps Green?

We are working with the council, Anglian Water, and other stakeholders on actions to identify and then reduce any sources. The responsibility and powers to resolve different sources lies with various organisations and authorities.

We have an agricultural regulatory officer visiting farms in the local area to check compliance with environmental legislation.

We are committed to determining all inputs that are negatively impacting the water quality. Bathing water samples in the ’24 season will be filtered and stored for DNA analysis.

As well as water sample data, we are investigating other monitoring data in the area (through the placement of a sonde) and will continue to investigate pollution incidents reported to us.