How much / many contaminants are discharged into the environment?
How much / many contaminants are discharged into the environment? » How are pollutants measured? » What are the levels of dangerous substances found in the environment? » What are the levels of contaminants discharged into the sea?
How much / many contaminants are discharged into the environment?
Some releases are permitted (known as consented discharges) as long as they are within legal limits set for each substance or industrial facility. Consented discharges must meet (comply) with environmental quality standards (EQS).
How are pollutants measured?
We monitor the following sites to see if they comply with EQS:
- Sites below discharges from industrial plants and sewage-treatment works where effluent is likely to contain dangerous substances
- Sites just upstream of the tidal limits of major rivers
- The actual discharge itself, to check that it complies with its discharge consent.
What are the levels of dangerous substances found in the environment?
Since 1990 levels of the most toxic substances discharged into the environment (called List I substances) have fallen (Indicator: Dangerous substances).
What are the levels of contaminants discharged into the sea?
The UK has signed up to two conventions on contaminants to the sea: the North Sea Conference and the OSPAR Convention. The objective of these conventions is to reduce the load of contaminants discharged to the North Sea from the member states that border this area.
The total loads and sources of contaminants vary each year and around the coasts of England and Wales. We measure the levels of each contaminant in the sea every year and compare them to reduction targets that the North Sea Conference set for 1995. Most contaminants have met their 1995 target reductions due to industries changing the way they operate, people switching to unleaded petrol and restrictions on the use and availability of some of the most hazardous substances.
Higher than normal river flows and rainfall effluent rates at outflow pipes can affect the levels of the more common substances. Inputs of substances that are less common in the environment (such as cadmium and mercury) are not as affected by river flows.
Zinc and nitrogen levels are still above their target reductions. Naturally occurring zinc artificially boosts the levels we record. The high nitrogen levels come from sewage works and fertilisers used on farmland. Higher than normal rainfall can increase the amount of nitrogen washed off farmland into rivers.
Find out more
More details on types of dangerous substances, Environmental Quality Standards (EQS) and monitoring:
Find out about substances released in to the environment near where you live: