Water quality
This data was last collected on 29/11/2023 and displays an average.
WATER pH LEVEL IS GOOD
pH LEVEL KEY
- Strongly Acidic Less than
- Weakly Acidic
- Neutral
- Weakly Alkaline
- Strongly Alkaline More than
The standard range for tap water is 6 to 9, and for a chalk stream it is 7.4 to 8.7. This is because chalk bedrock can influence the pH of water. In this case, the chalk is creating water that is more alkaline because the chemical components of the chalk cause a reduction in hydrogen ions. The brown shaded areas show what we would expect the pH to be for this site.
What does this all mean?
The pH level is a measure of how acidic or alkaline water is. The pH scale ranges between 0 and 14, where 7 is neutral, less than 7 is acidic, and more than 7 is alkaline. It is measured by taking a small sample of water, which is analysed at a laboratory to determine how acidic or alkaline the water is.
It is important that pH is measured because if the water is too acidic it can affect aquatic life and if it is too alkaline it can cause ammonia toxicity which will alter the water quality.
Temperature and Dissolved Oxygen
This data was last collected on 29/11/2023 and displays an average.
The average water temperature for the last seven days
The average dissolved oxygen for the last seven days
What does this all mean?
Dissolved oxygen is the measure of oxygen available in the water for all aquatic life to live on. Dissolved oxygen depends on temperature and atmospheric pressure; all three need to work together to create enough oxygen for organisms to live.
The temperature of the water is important because it can impact all aquatic life. As the temperature rises, dissolved oxygen levels decrease, which can cause negative effects on the organisms that live there.
Water temperature is measured on-site using a thermometer. Dissolved oxygen levels are analysed at a laboratory.
Ammonia and Phosphate status
This data was last collected on 29/11/2023 and displays an average.
Ammonia - 0.08mg/l
Ammonia levels – 90th percentile
- High - Levels less than 0.3
- Good - Levels between 0.3 and 0.6
- Moderate - Levels between 0.6 and 1.1
- Poor - Levels between 1.1 and 2.5
- Bad - Levels greater than 2.5
Phosphates - 790µg/l
Phosphate levels – 95th percentile
- High - Levels less than 50
- Good - Levels between 50 and 120
- Moderate - Levels between 120 and 250
- Poor - Levels between 250 and 1000
- Bad - Levels greater than 1000
What does this all mean?
When the level of detected ammonia and phosphate is low, the water is in ‘good’ or ‘high’ quality. This is represented by the green and blue raindrops, and the tick symbols. These ranges are based on the Water Framework Directive.
Ammonia is an essential plant nutrient but can be toxic in large volumes. If ammonia levels are elevated, it will lead to accelerated growth of algae. This can make it harder for fish and other invertebrates to survive. Elevated levels of ammonia are generally caused by domestic sewage and fertiliser.
Phosphorus is a nutrient used by plants to survive, but a large amount of it in a watercourse can lead to a reduction in dissolved oxygen.
Metal traces found in the Pix Brook
This data was last collected on 29/11/2023 and displays an average.
What does this all mean?
Microscopic quantities of metals in watercourse affect water quality, high levels of the metals can have an impact on aquatic life. The pass / fail levels for the metal traces are based on Environmental Quality Standard (EQS).
These limits have been set to control what is discharged into our watercourses, so they don’t become unhealthy.
Nickel
Nickel is a nutritionally essential mineral for some animal species, microorganisms and plants. It occurs in the environment from natural (weathering of rocks) and anthropogenic (mining and industrial) sources. Nickel has many industrial and commercial uses, leading to increased emissions of it into the environment.
A ‘fail’ is defined as more than 4 micrograms per litre (4 μg/l ) detected in the water.
Cadmium
Cadmium is not needed to support aquatic life but it is monitored to make sure there are not high traces of the metal as it can have toxic effects even at low levels.
A ‘fail’ is defined as more than 0.25 micrograms per litre (0.25 μg/l ) detected in the water.
Copper
At low concentrations, copper is an essential nutrient to aquatic life but is toxic at high concentrations.
A ‘fail’ is defined as more than 1 micrograms per litre (1 μg/l ) detected in the water.
Zinc
At low concentrations, zinc is an essential nutrient to aquatic life but is toxic at high concentrations.
A ‘fail’ is defined as more than 10.9 micrograms per litre (10.9 μg/l ) detected in the water.
Magnesium and Calcium
Magnesium and Calcium are not classed as toxic so have no Environment Agency standard pass or fail levels. They are both related to water hardness and are essential elements to aquatic life. The level of these impact the toxicity of other metals.
Turbidity Levels
This data was last collected on 29/11/2023 and displays an average.
Turbidity Levels is:
5 NTU
0 - 5
6 - 10
11+
Turbidity (the cloudiness of the water) can vary in natural environments from between 1 or 2 Nephelometric Turbidity Unit (NTU) in fresh water to 10 or 20 NTU in rivers with sediment. The standard turbidity from tap water is 4 NTU.
After major storm runoff events, turbidity levels can spike significantly, which can cause stress to aquatic life in the long term. This is because it is harder for light to penetrate the water, causing a reduction in photosynthesis.