To mark International Action Day For Rivers on March 14th, local environmental campaigner and activism officer of Colchester Green Party, Kemal Cufoglu, tested the River Colne for 16 parameters, including, heavy metals, bacteria caused by sewage pollution and algae causing chemicals.

Key Findings: Presence of E. Coli, Heavy Metals and Chloride

1) E coli
Most shockingly, the bacteria check found coliforms including E.coli at 5 cfu/ml. Following 48-hour and 72-hour observation, the bacteria test that looked for coliforms including E. coli found that harmful coliform bacteria is highly likely to be present in the river and that therefore the River Colne must be considered unsafe. According to the Centers for Disease Control and Prevention, the presence of E. coli is a sign that it has been contaminated with faeces from infected humans or animals. This can enter the water through sewage overflows, and sewage systems that are not working properly, polluted stormwater runoff and agricultural runoff. The presence of E. coli and harmful coliform bacteria not only makes it dangerous for humans and animals alike but poses a serious threat to nearby wells and water resources. In case of a flood or storm, it can easily contaminate surrounding wells and water resources.
2) Heavy Metals
Heavy metals that Kemal tested included Cadmium, which damages the lung and kidneys, Mercury, which damages the peripheral nervous system, Nickel and Zinc. The total result we got in this category was between 50->100 µg/l (microgram per litre). Considering that the inland surface waters’ legal limit for mercury is 0.07 µg/l, nickel is 4µg/l, zinc is 5 µg/l and cadmium is between less than 0.08-0.25µg/l, results from the River Colne is extremely concerning.
A 50 – >100 µg/l result means that we may have harmful heavy metals that are 10 to 1000 times more than the legal limits stated by the World Health Organization as well as certain EU directives that UK is adhering for the moment. Heavy metals not only lead to organ failure and skin disease in humans, but they can also spread their toxicity to plants and animals as well as those consuming them. Therefore, we urge residents and dog owners to be extra mindful when considering a quick dipping or fishing on River Colne.
3) Chloride
Chloride is a chemical to be found in most soils, rocks or minerals. Chloride contaminated rivers and groundwater not only turn them unsuitable for humans to drink, but high levels of chloride can kill aquatic plants and animals. While 45mg/l for rivers is considered normal, we have found that River Colne has a staggering 500mg/l, 11 times more than this limit. Chloride sources include animal waste, potash fertilizer (KCI), septic tank effluent and sewage, and can also damage infrastructure by causing plumbing corrosion.
4) Sulfate
Sulfate was another highest-scored chemical with rates between 250-500mg/l. Sulfates can be occurring or the result of municipal or industrial discharges with point sources including sewage treatment plants, industrial discharges and runoff from fertilized agricultural land. In humans, the concentrations we found in river Colne can affect the digestive system and cause a laxative effect. In addition to this, sulphates contribute to the acidification of surface water and soil and can contribute to acid rain and fog that damage ecosystems, forests and plants.
5) Total Alkalinity
River Colne had the highest score rate on the alkalinity scale, at 500ppm. Total alkalinity buffers against the reduction in pH and causes the pH of the water to increase further. This is particularly worrying as the current pH level of 8.5-10.5 is already above the optimum level of 7.4 and high total alkalinity leads to degradation of habitats.
6) Less concerning results
Results that were less concerning were: Iron (low), copper (low), total chlorine (low), hydrogen sulfide (low/not detected), lead (not found) and pesticides atrizine and simazine (not found)

Following the guidelines, Kemal has reported the findings to Anglian Water and requested a confirmatory test. Additionally, he notified the Rivers Trust and also made a map request from digdat Utilities detailing the locations of our local water infrastructure and assets (including both underground assets and above ground assets such as pumping stations, water treatment works and water recycling works).

Statements from Kemal Cufoglu and Richard Kirkby-Taylor
Kemal’s statement:
“Basically our river is a flowing toxic cocktail. It has E. coli, dangerous heavy metals that are potentially 10 to 1000 times above the legal limit, and chloride levels that are 11 times higher than levels that would be considered normal for a river. River Colne also hit the max score in sulfate, total alkalinity and total hardness. I would be worried to have my dog jump into the river, and a quick dip in the river during hot summer days would be out of the question. The presence of heavy metals in the river such as cadmium, mercury, nickel and zinc not only make it a toxic habitat for animals and plant life alike, but a transmittable health hazard for those using untreated river water or do fishing.”
Green campaigner Richard Kirkby-Taylor states:
“The levels of E.Coli, Sulphate and heavy metal do suggest we have untreated sewage in the river which flows through the heart of our town, then out past Wivenhoe and Brightlingsea. Not only are these contaminants almost certainly damaging our ecosystem, they are probably harming the residents of Colchester and the surrounding areas, ultimately putting additional strain on the NHS. This is exactly the kind of problem that the weakening of our environmental regulations causes and why we have to push back against them at every level. We will be reaching out to water recycling and sewage treatment centres to ensure they are abiding by the highest standards and continue to put pressure on local and regional authorities to lobby the government to not weaken environmental regulations, but to strengthen them.”