1. WATER POLLUTION ASSESSMENT
Environmental Standards
and
Discharge Consents.

2. 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.

3. 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”

4. 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.

5. 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)

6. 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

7. 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

8. 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 ( ) such as:
the Surface Water (Abstraction) Directive (1975),
the Bathing Water Quality Directive (1976),
the Freshwater Fish Directive (1978),
the Shellfish Water Directive (1979)

9. 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, )

10. 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

11. 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

12. 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

13. 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

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

15. 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

16. 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)

17. 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

18. 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

19. 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

20. 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

21. 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

22. 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.

23. 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 % removal (<100,000 pe)
< 10 mgN/l, or minimum % removal (>100,000 pe)

24. 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.

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

26. 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