PURPOSE: This regulation sets forth the minimum requirements for laboratory testing to ensure adequate wastewater treatment systems operation.

1. (1) Definitions. Definitions as set forth in the Missouri Clean Water Law and 10 CSR 20- 2.010 apply to the terms to be used in this rule, unless the context clearly requires otherwise.
2. (2) Operational laboratory tests and related monitoring for wastewater treatment systems control are a supplement to the Missouri State Operating Permit (MSOP) requirements. These operational monitoring reports shall be submitted to the department along with the MSOP discharge monitoring reports.
3. (3) The department may modify monitoring frequency required in this rule based upon the department’s judgement of monitoring needs for process control at a specified facility.
4. (4) These requirements for laboratory tests shall apply to all wastewater treatment systems owned or operated by or for municipalities, public sewer districts, or other local government entities, private sewer companies regulated by the Public Service Commission, and the state agencies or any subdivision of them, with a population equivalent, as defined in 10 CSR 20-9.020, greater than two hundred (200). All other systems are exempt.

5. (5) Minimum monitoring requirements to ensure adequate wastewater treatment systems in-plant operational control are as follows:

   1. (A) Lagoons

      1. 1. Discharging - Two (2)/Week Frequen-

cy. Precipitation Flow Influent or Effluent pH Primary Cell D.O. Primary Cell

1. 2. Non-Discharging – Two (2)/Month

Frequency. Precipitation Flow Influent or Effluent pH Primary Cell D.O. Primary Cell

1. (B) Mechanical Plants.

   1. 1. All types—daily (Monday – Friday)

frequency. Precipitation Flow pH Temperature Aeration basin

1. 2. Additional laboratory test require-

ments for wastewater activated sludge processes and modifications: Influent TSS 1/week Settleability

D.O.

Temperature

1. 3. Additional tests for facilities having

digesters: Anaerobic pH (Monday – Friday) Temperature (Monday – Friday) D.O.

1. (C) Recirculating filter media beds: Pressure
2. (D) Facilities which chlorinate for disinfection shall perform total chlorine residual analyses of the effluent on a daily (Monday – Friday) basis during those periods when chlorination facilities are in use.
3. (E) Facilities employing disinfection technology other than chlorine shall have disinfection process control testing parameters and frequency determined by the department on a case-by-case basis.

1. (6) Laboratory procedures shall be performed in accordance with 10 CSR 20-7.015.
2. (7) A copy of all reports required by this rule shall be retained by the facility for a minimum of three (3) years.

AUTHORITY: section 644.026, RSMo 2016.* Original rule filed July 15, 1976, effective July 1, 1977. Amended: Filed Nov. 1, 1983, effective July 1, 1984. Amended: Filed July 29, 1994, effective March 30, 1995. Amend- Influent or Effluent Influent Mixed Liquor 1/week Daily (Monday – Friday) (sample contact and reaeration basins for contact stabilization) Daily (Monday – Friday) (sample contact and reaeration basins for contact stabilization) Daily (Monday – Friday) (sample contact and reaeration basins for contact stabilization) Aerobic Daily — Daily — — Daily (Monday – Friday) 2/year by measuring squirt height in each zone at the orifice furthest from the pump. Use each pump independently during the monitoring to ensure each pump is functioning. 10 CSR 20-9 ed: Filed Nov. 3, 1997, effective July 30, 1998. Amended: Filed June 13, 2018, effective Feb. 28, 2019. *Original authority: 644.026, RSMo 1972, amended 1973, 1987, 1993, 1995, 2000, 2012, 2014.