WATER POLLUTION ASSESSMENT Environmental Standards and Discharge Consents.

Environmental Regulation Regulation of impacts on the environment is now a crucial area of public policy. Over $500 billion p.a. is spent globally on compliance. Environmental impact without any regulation would cost many times that sum.

Setting Standards. Scientific Understanding The starting point for setting environmental standards. Essential to determine dose-effect relationships. Uncertainties and limitations in the data must be recognised. the science must provide a firm basis for policy decisions Precautionary Principle Mechanism* identify problem, policy, set standard, monitor *see 21st Report of Royal Commission on Environmental Pollution “Setting environmental standards”

Environmental Standards Forms of Environmental Standard. Biological. Limits of physiological change.e.g. lead in blood. Biomarkers of exposure, not effect. Inform after exposure has occurred, hence do not prevent the effect. Exposure from a number of routes, hence no indication of course of action.

Environmental Standards Forms of Environmental Standard. Exposure. Acceptable doses at the point of entry to an organism. Tolerable Daily Intakes (TDIs) International Programme on Chemical Safety (IPCS) UNEP, ILO, WHO Often standards not set (due to lack of information). Acceptable Daily Intakes (ADIs) Mainly internationally based health standards. Food and Agriculture Organisation/WHO e.g. pesticides, medicines and max residue levels (MRLs)

Environmental Standards Forms of Environmental Standard. Environmental Quality. Acceptable concentration of substance in the environment (air, soil, water) Water Quality Objectives (WQO), Water Quality Standards (WQS) benefit the natural environment. Freshwater fish, Shellfish benefit human health bathing waters quality of water abstracted for use as drinking water

Environmental Standards Forms of Environmental Standard. Emission load of pollutant discharged to the environment car exhaust but BATNEEC probably better (e.g. legislate for catalytic converters) Effluent Discharges main basis for controlling organic pollution and toxic substances in Europe UK also uses WQO

Environmental Standards and Objectives Therefore, two different approaches to tackle water pollution: 1. The Water Quality Objective (WQO) approach defines the minimum quality requirements of water to limit the cumulative impact of emissions. Achieves a certain quality level of the water not harmful for the environment and human health (even after discharges of polluted water). E.g. early EU water directives (1970-1980) such as: the Surface Water (Abstraction) Directive (1975), the Bathing Water Quality Directive (1976), the Freshwater Fish Directive (1978), the Shellfish Water Directive (1979)

Environmental Standards and Objectives 2. The Emission Limits Value (ELV) approach maximum quantities of pollutants allowed to be discharged from a particular source into the aquatic environment. Specifies the efficiency of wastewater treatment Specifies what quantities of pollutants may be released Subsequent EU directives (1990s) the Urban Waste Water Treatment Directive (1991) the Nitrates Directive (1991) the IPPC Directive (Integrated Pollution Prevention and Control, 1996)

Future - Environmental Standards and Objectives 3. Future approach Water Framework Directive (2000/86/EEC) aims expanding the scope of water protection to all waters, surface waters and groundwater achieving "good status" for all waters by a set deadline (2015) water management based on River Basins “combined approach" of emission limit values and quality standards getting the prices right getting the citizen involved more closely streamlining legislation

Reviewing Standards. Numerical standards. Key Changes in the Policy process. Numerical standards. Maturity of toxicology and ecotoxicology Advances in measurement science. Improved understanding of the behaviour of substances in the environment. Pan European Policies

Discharge Consents basis for setting discharge consents. water quality objectives (WQO) river ecosystem classification scheme (RE1 - 5) Statutory Water Quality Objectives (SWQO) (currently under consideration in UK for use in planning) Statutory Emission Standards UWWT Directive 1991 Dangerous Substances Directive 1976

Discharge Consents Aim - provide adequate monitoring of compliance with standard Numerical standards should always incorporate protocols for sampling and measurement. Laboratories should be accredited to appropriate proficiency testing schemes. Numerical standards should consider the extent of statistical variation (look-up tables) Self regulation - EA has passed sampling responsibility to water undertaker

Discharge Consents History mid 19C Typhoid, TB, Cholera epidemics , mortality 46/1000 Royal Commission on Sewage Disposal nine reports 1901 -1915 recommended a discharge standard 20 mg/l BOD, 30 mg/l SS

Discharge Consents Recent legislation Water Industry Act (1991) water undertakers can charge, and set consents to sewer Water Resources Act (1991) EA authorised to set discharge consents to watercourses Urban Wastewater Treatment Directive (1991) i.e UWWTD pan-european standards

Discharge Consents Apply to “Controlled Waters” virtually all freshwaters, groundwaters, tidal and coastal waters Descriptive consents Discharges that are small, have a low potential to impact the environment (c. 50,000 in UK) 2. Numeric Consents Discharges having most potential to affect the quality of the receiving water (i.e. large flows, Industrial, STW) may apply to an individual substance or group of substances (c. 30,000 in UK) based on Royal Commission Standards, and EU Directives (UWWT Directive)

Discharge Consents Water Companies Water plc’s set their own consents for sewer discharges For Commercial and Industrial discharges Ensures the performance of Municipal WWT Plant (compliance) Review of existing consents appeals Granting of new consents

UWWT Directive (1991) Size of plant < 2000 pe are exempt > 2000 pe before 2006 to comply Sensitive waters EA and English Nature interpret the definition of “sensitive waters” Habitats Directive(1992) Special Protection Areas (SPAs) Birds Directive (1979) Special Areas of Conservation SAC

UWWT Directive (1991) Samples 24h composite for 95%ile comparison for Upper tier usually 2 X 95%ile limit waived for exceptional weather conditions Parameters BOD5, COD, Suspended Solids (optional) N & P

UWWTD Monitoring for BOD Is Final Effluent < 25 mg/l ? PASS YES NO Is BOD removal > 70% ? PASS YES NO Look-up table FAIL/Pass YES Is Final Effluent < 50 mg/l ? NO Upper-Tier FAIL

UWWTD Monitoring for COD Is Final Effluent < 125 mg/l ? PASS YES NO Is COD removal > 75% ? PASS YES NO Look-up table FAIL/Pass YES Is Final Effluent < 250 mg/l ? NO Upper-Tier FAIL

UWWTD Monitoring for Phosphorous STWs discharging to Sensitive waters (inland) must also demonstrate Phosphorous removal. The measurement criteria is different: Based on annual “average concentration” average for year (1st January to 31st December) < 2 mgP/l, or minimum 80% removal (<100,000 pe) < 1 mgP/l, or minimum 80% removal (>100,000 pe) e.g. A STW <50,000 pop. has 12 samples taken, meaning that the ‘total’ for the year must not exceed 12 x 2 = 24, (2mg/l average) or must have achieved 80% removal.

UWWTD Monitoring for Nitrogen STWs discharging to Sensitive waters (inland) must also demonstrate Nitrogen removal. Sum Individual sample results. Divide by the number of samples taken to give an average. average for year (1st January to 31st December) < 15 mgN/l, or minimum 70 - 80% removal (<100,000 pe) < 10 mgN/l, or minimum 70 - 80% removal (>100,000 pe)

UWWTD Monitoring Key Points UWWTD uses the same Look-up Table as Water Resources Act. 12 samples taken - maximum number of parameter failures permitted = 2 24 samples taken - maximum number of parameter failures permitted = 3 UWWTD samples are based on a fixed 12 month programme running from 1st January - 31st December. (Spot Water Resources Act compliance is based on a rolling 12 month programme) All works are sampled (24 h composite) on pre-determined dates agreed with the Environment Agency.

Coastal Sites Bathing Water Directive typically enterovirus critical Modelling dispersion & dilution Standard 0 PFU/10litres typically need 5 log removal treatment & dispersion/dilution (typ. 4 log) UV disinfection (typ. 1 - 2 log)

Future Improvements WQOs Continually Reviewed LEAPs Asset management Plans (AMP4,2005) Undertaker / EA / DEFRA capital investment for “best ecological effect” Upgrading works Relaxation of Consent (typ. 6 months) interim measures better primary settlement supplementary oxygen