Current through Register Vol. 50, No. 9, September 20, 2024
Section IX-711 - Secondary Treatment for Sanitary SewageA. Applicability. This Section provides information on the level of effluent quality attainable through the application of secondary or equivalent treatment.B. Definitions. The following definitions are applicable to terms used in this Section. Definitions of other terms and meanings of abbreviations are set forth in LAC 33:IX.107. BOD5- the five day measure of the pollutant parameter biochemical oxygen demand.
CBOD5-the five day measure of the pollutant parameter carbonaceous biochemical oxygen demand.
C. Secondary Treatment for Sanitary Sewage. The following paragraphs describe the minimum level of effluent quality attainable by secondary treatment in terms of BOD5, TSS, and pH. 1. BOD5a. The 30-day average shall not exceed 30 mg/L.b. The 7-day average shall not exceed 45 mg/L.c. The 30-day average percent removal shall not be less than 85 percent.d. At the option of the administrative authority, in lieu of the parameter BOD5, the parameter CBOD5 may be substituted with the following levels of the CBOD5 effluent quality provided: i. the 30-day average shall not exceed 25 mg/L;ii. the 7-day average shall not exceed 40 mg/L;iii. the 30-day average percent removal shall not be less than 85 percent.2. TSS a. The 30-day average shall not exceed 30 mg/L.b. The 7-day average shall not exceed 45 mg/L.c. The 30-day average percent removal shall not be less than 85 percent.D. Treatment Equivalent to Secondary Treatment. The following levels of treatment may be considered equivalent to secondary treatment. | Concentration in mg/L |
Principle Treatment Process | 30-day average | 7-day average |
| BOD | TSS | BOD | TSS |
1. Trickling Filter |
a. New | 30 | 30 | 45 | 45 |
b. Existing minor | 45 | 45 | 65 | 65 |
c. Existing major | 30-45* | 30-45* | 45-65 | 45-65 |
2. Oxidation Pond |
a. New | 30 | 90 | 45 | 135 |
b. Existing minor | 45 | 90 | 65 | 135 |
c. Existing major | 30-45* | 90 | 45-65 | 135 |
*Actual number would be established after case-by-case review of individual facilities.
La. Admin. Code tit. 33, § IX-711
Promulgated by the Department of Environmental Quality, Office of Water Resources, LR 11:1066 (November 1985), amended LR 21:945 (September 1995).AUTHORITY NOTE: Promulgated in accordance with R.S. 30:2001 et seq., and in particular Section 2074(B)(3) and (B)(4)