Paragraph 5 I1
Scotland
The points of discharge of urban waste water shall be chosen, as far as possible, so as to minimise the effects on receiving waters.
TABLE 1
REQUIREMENTS FOR DISCHARGES FROM URBAN WASTE WATER TREATMENT PLANTS SUBJECT TO REGULATION 5(1) AND (2)
The values for concentration or for the percentage of reduction shall apply.
| Parameters | Concentration | Minimum percentage of reduction | Reference method of measurement |
|---|---|---|---|
| Analyses concerning discharges from lagooning shall be carried out on filtered samples; however, the concentration of total suspended solids in unfiltered water samples shall not exceed 150 mg/l. | |||
| Biochemical oxygen demand (BOD5 at 20°C) without nitrification | 25 mg/1 O2 | 70-90 | Homogenized, unfiltered, undecanted sample. Determination of dissolved oxygen before and after five-day incubation at 20°C ± 1°C, in complete darkness. Addition of a nitrification inhibitor. |
| Chemical oxygen demand (COD) | 125 mg/1 O2 | 75 | Homogenized, unfiltered, undecanted sample Potassium dichromate. |
TABLE 2
REQUIREMENTS FOR DISCHARGES FROM URBAN WASTE WATER TREATMENT PLANTS TO SENSITIVE AREAS WHICH ARE SUBJECT TO EUTROPHICATION AS IDENTIFIED IN SUB-PARAGRAPH (a) OF PART I OF SCHEDULE 1
One or both parameters may be applied depending on the local situation.The values for concentration or for the percentage of reduction shall apply.
| Parameters | Concentration | Minimum percentage of reductionf1 | Reference method of measurement |
|---|---|---|---|
(1) Reduction in relation to the load of the influent. | |||
(2) Total nitrogen means: the sum of total Kjeldahl-nitrogen (organic N+NH3), nitrate (NO3)-nitrogen and nitrite (NO2)-nitrogen. | |||
| Total phosphorus | 2 mg/1 P (10,000–100,000 p.e.) 1mg/1 P (more than 100,000 p.e.) | 80 | Molecular absorption spectrophotometry |
| Total nitrogenf2 | 15 mg/1 N (10,000–100,000 p.e.) 10 mg/1 N (more than 100,000 p.e.) | 70-80 | Molecular absorption spectrophotometry |
Annotations
Commencement
- I1
Sch. 3 Pt. I para. 5 in force at 30.11.1994, see reg. 1
Footnotes
- f1
(1)
Reduction in relation to the load of the influent.
- f2
(2)
Total nitrogen means: the sum of total Kjeldahl-nitrogen (organic N+NH3), nitrate (NO3)-nitrogen and nitrite (NO2)-nitrogen.