South Carolina Code of Regulations
Chapter 61 - DEPARTMENT OF HEALTH AND ENVIRONMENTAL CONTROL
Subchapter 61-9 - Water Pollution Control Permits
Subchapter 61-9.403 - GENERAL PRETREATMENT REGULATIONS FOR EXISTING AND NEW SOURCES OF POLLUTION
Appendix 61-9.403.E - SAMPLING PROCEDURES
Current through Register Vol. 48, No. 9, September 27, 2024
I. COMPOSITE METHOD
II. GRAB METHOD
If composite sampling is not an appropriate technique, grab samples should be taken to obtain influent and effluent operational data. A grab sample is an individual sample collected over a period of time not exceeding 15 minutes. The collection of influent grab samples should precede the collection of effluent samples by approximately one detention period except that where the detention period is greater than 24 hours such staggering of the sample collection may not be necessary or appropriate. The detention period should be based on a 24-hour average daily flow value. The average daily flow should in turn be based upon the average of the daily flows during the same month of the previous year. Grab sampling should be employed where the pollutants being evaluated are those, such as cyanide and phenol, which may not be held for an extended period because of biological, chemical, or physical interactions which take place after sample collection and affect the results.