Situation and Compliance Report on the Disposal of Urban Wastewater and Sludge in Scotland 2018

Footnotes

1 The data reported by the UK was then included in the 11th technical assessment on UWWTD implementation produced by the EC in May 2022

2 Relevant SEPA regulatory methods and supporting guidance include: SEPA Regulatory Method - Assessment of Numeric Discharge Quality Conditions (for CAR, UWWTD and PPC Compliance) (WAT-RM-40 v5.1) (October 2017) and SEPA Supporting Guidance – Communications Protocol for compliance sampling between Scottish Water and SEPA (WAT-SG-42 v3.2), (February 2020)

3 A measurement of organic biodegradable load, and a population equivalent of 1 (1 p.e.) is the organic biodegradable load having a five-day biochemical oxygen demand (BOD5) of 60g of oxygen per day, the load being calculated on the basis of the maximum average weekly load entering the treatment plant during the year, excluding unusual situations such as those due to heavy rain.

4 See UWWTD National Summary Chapter 2018, The United Kingdom, Section 3: Legal Compliance

5 It should be noted that this includes the load generated by households and businesses, hence why the generated load, which relates to only agglomerations with a p.e. of 2,000 or more and, therefore, within the scope of the UWWTR, is greater than Scotland’s population.

6 Regulation 5(1) details the requirement for treatment plants to provide secondary treatment (or equivalent) for all agglomerations with 10,000 or more or agglomerations with a p.e. of 10,000 or more or agglomerations with a p.e. of between 2,000 and 10,000 that discharge to freshwaters or estuaries. Schedule 3 details the requirement for Biochemical Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) sampling and associated concentration limits.

7 The enrichment of water by nutrients, especially compounds of nitrogen and/or phosphorus, causing an accelerated growth of algae and higher forms of plant life to produce an undesirable disturbance to the balance of organisms present in the water and to the quality of the water concerned.

8 Regulation 5(2) details the requirement for more stringent treatment for discharges from agglomerations with a population equivalent of more than 10,000 into sensitive areas, or into the relevant catchment areas of sensitive areas where the discharges contribute to the pollution of these areas. Schedule 3 details the requirement for Total phosphorus and Total nitrogen sampling and associated concentration limits.