Useful documents from elsewhere

Water quality standards

The Water Framework Directive is the bible for water quality standards. It includes standards for rivers, lakes and coastal waters. It includes standards for the shape of water bodies, the chemical status of water bodies and the fauna and flora living in water bodies. As scientists learn more about how the WFD standards apply to UK waterways, they publish improvements to the WFD standards. The organisation charged with updating standards is UKTAG.

However, much of the main Coquet river is SSSI (Site of Special Scientific Interest). For these areas, there are more stringent water quality standards. These are listed in the Common standard monitoring guidance for estuaries and Common standard monitoring guidance for rivers. The specific targets for descriptions for SSSI sections of the river and estuary are the European Site Waterbody targets.

Phosphorus

Phosphorus enters water largely from sewage (human or animal) and is a major cause of eutrophication in freshwater. The Environment Agency has produced a summary paper on this topic (Phosphorus and freshwater eutrophication). Also produced by the Environment Agency, an earlier paper on the same topic (Phosphorus and freshwater eutrophication pressure).

Standards for Phosphorus in water are set in the WFD and Common Standards documents above.

Nitrogen

Nitrate is from agricultural fertiliser or the breakdown of ammonia from sewage. Nitrate is of concern because high levels are toxic to fish and can cause illness in humans. Understanding standards for nitrogen in water is complicated, especially in estuarine water. We have therefore produced a paper specifically explaining the standards that CRAG use (Nitrogen in water). In freshwater, perhaps the key document for nitrate standards is Martyn Kelly’s blog ‘This is not a nitrate standard …‘.

There are no standards for nitrate in the Water Framework Directive or the SSSI Common standards documents. However, there is are nitrate and nitrite standard for drinking water in The Water Supply (water quality) Regulations, and the same nitrate standards in the Nitrate Pollution Prevention Regulations. The nitrate pollution prevention regulations only apply to Nitrate Vulnerable Zones. All the lower Coquet and tributaries are within a Drinking Water Safeguard Zone, a subset of Nitrate Vulnerable Zones. A useful summary of the affect of nitrate in water has been produced by the Environment Agency (Nitrate Challenges for the water environment).

Conductivity and salinity

Three important features of water for which there are not standards in the Water Framework Directive but which indicate a change in water quality are Conductivity, Salinity and Total Dissolved Solids (see this website for an excellent description). Each water course will have a natural level of conductivity, largely driven by the groundwater that flows into the burn. After rain, the conductivity might decrease (because rainwater dilutes the groundwater) or might increase (because the rain increase the volume of agricultural run-off and/or sewage entering the water). It is the change in conductivity rather than the natural level that indicates a change in water quality.

Salinity measures the total dissolved salts in water. Conductivity (or electrical conductivity) measures the total dissolved ions (charged particles) in water. Total dissolved solids (TDS) measure the dissolved salts and the dissolved organic molecules in water. Often salinity and TDS measurements are estimated from conductivity measurements.

Conductivity measurements are dependent on temperature (for example, see this paper The effect of temperature on conductivity measurement). The EC meters used by CRAG automatically adjust the measurement for temperature.

Bathing water and E. coli

Bathing Waters are another classification for water bodies with their own set of quality standards. Perhaps most relevant to CRAG are the standards for E. coli and Intestinal enterococci bacteria in the Bathing Water Regulations. The Environment Agency are required to monitor designated bathing waters using the Bathing Water Regulations. There is an application process to designate a bathing water. The document Canadian Recreational Water Quality: Indicators of fecal contamination gives a very thorough overview of everything to do with E. coli and Intestinal enterococci bacteria in water.

Eutrophication and macroscopic algae monitoring

Algal blooms (or eutrophication) in water are a sign of high nutrient levels. The Water Framework Directive includes standards for phytoplankton (microscopic algae floating in the water) and macroscopic algae (seaweed) in estuary and coastal waters. The method recommended for measuring opportunistic macroalgae blooms in estuaries has been developed by UKTAG.

A method for measuring macroscopic algae in freshwater has been developed. The RAPPER (Rapid Assessment of PeriPhyton Ecology in Rivers) method is described in an academic paper, has been described in a summary format by the Environment Agency working with the Wye Partnership, and a summary sheet with pictures to help identification has been developed.