Statutes, codes, and regulations
Virginia Administrative Code
Title 9 - ENVIRONMENTAgency 25 - STATE WATER CONTROL BOARDChapter 790 - SEWAGE COLLECTION AND TREATMENT REGULATIONSPart IV - Reports and Forms
Article 1 - Reports
Section 9VAC25-790-970 - Operational testing and control

9 Va. Admin. Code § 25-790-970

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Current through Register Vol. 41, No. 4, October 8, 2024
Section 9VAC25-790-970 - Operational testing and control
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

9 Va. Admin. Code § 25-790-970

Former 12VAC5-581-1030 derived from Virginia Register Volume 18, Issue 10, eff. February 27, 2002; amended and adopted as 9VAC25-790-970, Virginia Register Volume 20, Issue 9, eff. February 12, 2004.

Statutory Authority

§ 62.1-44.19 of the Code of Virginia.