Virginia Administrative Code
Title 9 - ENVIRONMENT
Agency 25 - STATE WATER CONTROL BOARD
Chapter 790 - SEWAGE COLLECTION AND TREATMENT REGULATIONS
Part IV - Reports and Forms
Article 1 - Reports
Section 9VAC25-790-970 - Operational testing and control
Universal Citation: 9 VA Admin Code 9VAC25-790-970
Current through Register Vol. 41, No. 3, September 23, 2024
A. Minimum tests and frequency. Table D-l contains the typical minimum sampling and testing program for operational control of treatment works greater than 40,000 gallons per day.
B. Sampling instructions. The following sampling instructions should be followed when taking samples:
1. When samples are taken for
BOD5, COD, volatile suspended solids, and suspended
solids on influent and effluent streams, they should be composite
samples.
2. All other samples
should be grab samples.
| TABLE D-1. RECOMMENDED OPERATIONAL AND CONTROL TESTING. | ||
| Unit Process Parameters | Testing Location/Frequencies (see key for description) | |
| 1. Primary | ||
| a) DOB5/TSS/TVS | 1/bw; 2,3/2 | |
| b) settleable solids | 2, 3/d | |
| c) pH | 2,3,8/d | |
| 2. Suspended Growth Reactor | ||
| a) BOD5/nutrients | 1/bw; 2/w; 3/bw | |
| b) TSS/TVSS | 6/d; 13/w | |
| c) 30 minute SSV/pH/DO | 6/d | |
| d) microscopic exam. | 6/w | |
| 3. Attached Growth Reactors | ||
| a) BOD5/nutrients | 1/bw; 2/w; 3/bw | |
| b) TSS/TVS/microscopic exam. | 14/w | |
| c) pH, DO | 1/d; 2/w | |
| 4. Ponds of Lagoons | ||
| a) BOD5/nutrients | 1/w; 2/w | |
| b) TSS/microscopic exam. | 1/w; 2/w; 7/w | |
| c) pH/DO/temperature | 1/d; 7/d | |
| 5. Anaerobic Digestion | ||
| a) TS/TVS | 6,11,12/w; 8,9,10,13/bw | |
| b) pH/alkalinity/temp. | 6,12/d; 11,15/bw; 6/w; 13/bw | |
| 6. Aerobic Digestion | ||
| a) TS/TVS | 6,11,12/w; 13/bw | |
| b) settleable solids | 6/d | |
| c) pH/temperature | 6/d; 15/bw | |
| d) microscopic exam. | 6/w; 13/bw | |
| 7. Sludge Thickening | ||
| a) TS/TVS | 1,2/d | |
| b) settleable solids | 6/d | |
| 8. Sludge Dewatering | ||
| a) TS/TVS | 1,2,4,12/q | |
| b) pH/alkalinity | 15/q | |
| 9. Chemical Clarification | ||
| a) BOD5/COD/TSS/TYS | 1,2/w | |
| pH/alkalinity | 1,2,3,4,6/d | |
| b) settleable solids/flocculation | 1,2,6/d | |
| c) nutrients | 1,2/q | |
| 10. Tertiary Filtration | ||
| a) BOD5/TSS | 1,2/w | |
| b) pH/alkalinity | 1,2/d | |
| c) nutrients | 1,2/q | |
| TABLE D-1 - KEY | ||
| FREQUENCY | SAMPLING LOCATION | |
| d - Daily | 1. Process Influent | |
| w - Weekly | 2. Process Effluents | |
| bw - Biweekly | 3. Influent plus Return Waste Streams | |
| q - Daily when in operation | 4. Following Chemical Addition | |
| 5. Filtered Effluent | ||
| CONVENTIONAL PARAMETERS | 6. Contents of Reactor | |
| BOD5 - 5-day biochemical oxygen demand | 7. All Cells of Each Lagoon or Pond | |
| SS - Suspended solids | 8. Raw Sludge | |
| TS - Total solids | 9. Primary Sludge | |
| VS - Volatile solids | 10. Secondary Sludge | |
| DO - Dissolved oxygen | 11. Digester Influent | |
| NUTRIENTS - Forms of phosphorus and nitrogen as required by the certificate CTO issued. | 12. Treated Sludge | |
| 13. Return Sludge | ||
| 14. Attached Growth | ||
| 15. Process Supernatant | ||
Statutory Authority
§ 62.1-44.19 of the Code of Virginia.
Disclaimer: These regulations may not be the most recent version. Virginia may have more current or accurate information. We make no warranties or guarantees about the accuracy, completeness, or adequacy of the information contained on this site or the information linked to on the state site. Please check official sources.
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