Situation and Compliance Report on the Disposal of Urban Wastewater and Sludge in Scotland 2020

Footnotes

1 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)

2 See Schedule 3, Table 3 of the UWWTR

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.