Section 490. Monitoring, Chapter 640., Agency 5. Department of Health, Title 12. Health, Virginia Administrative Code

Article 4. Monitoring, Operation, and Maintenance Requirements

A. Discharging systems that discharge improperly treated effluent can endanger public health and threaten environmental resources. All discharging systems shall be routinely inspected and the effluent sampled to determine compliance with the effluent limitations set forth by the State Water Control Board in the General Permit and in accordance with 12VAC5-640-430 and 12VAC5-640-510. All testing requirements contained in this chapter are the responsibility of the system owner to have collected, analyzed, and reported to the department.

B. There are two types of testing recognized by this chapter: formal compliance testing and informal (process control) testing. Formal testing is conducted to determine either compliance or noncompliance with the General Permit. Informal testing is conducted to assess the treatment system's performance and to determine when additional formal compliance testing is necessary. Informal testing may support but shall not be the sole basis for revoking the approval of the system pursuant to 12VAC5-640-280.

C. All treatment systems shall undergo startup testing to assess the ability of the system to comply with the established performance requirements.

1. Treatment systems are considered generally approved for the purposes of establishing startup testing requirements only when all treatment components (i.e., biological treatment unit, disinfection, dechlorination, post-aeration, etc.) of the system are considered generally approved as described in 12VAC5-640-432.

2. All new discharging systems shall undergo formal startup compliance testing for parameters limited by the General Permit. The collection, storage, transportation, and analysis of all formal compliance samples shall be in accordance with the requirements of the General Permit.

a. For generally approved systems, the first formal compliance testing event shall occur 45 to 90 days after the system begins discharging. If the formal compliance test data indicate the system is in compliance with the General Permit, then the system will revert to annual formal compliance sampling in accordance with the General Permit. The initial sample may be used to comply with the first annual sampling requirement. If the testing data indicates that any parameter is out of compliance, subsection E of this section shall apply.

b. For nongenerally approved systems, the first formal compliance testing event shall occur 45 to 90 days after the system begins discharging. Three additional formal compliance testing events are to occur quarterly and at least 60 days apart. If the four startup compliance test data indicate the system is in compliance with the General Permit, then the system will revert to annual formal compliance sampling in accordance with the General Permit. If the testing data indicates that any parameter is out of compliance, subsection E of this section shall apply.

3. Informal (process control) testing shall be conducted monthly for at least six consecutive months beginning the second full month after the issuance of the operation permit. After successful startup of the treatment system, informal testing shall be conducted semiannually at a minimum and any time formal testing is conducted. Informal testing shall be in accordance with the approved operation and maintenance manual, which shall include at a minimum the tests listed in Table 3.3. The specific test, sample location, and frequency shall be itemized in the operation and maintenance manual for the treatment system.

D. Both formal and informal routine monitoring is required after a system successfully completes startup testing.

1. After a system successfully completes startup testing, the system formal testing reverts to the General Permit monitoring frequency for the parameters limited by the General Permit. The collection, storage, transportation, and analysis of all formal testing shall be in accordance with the requirements of the General Permit.

2. Informal (process control) testing shall be conducted during routine maintenance visits. The specific test, sample location, and frequency shall be itemized in the operation and maintenance manual for the treatment system. When an operation and maintenance manual is not available, informal testing shall be sufficient to assess the treatment system's performance. Table 3.3 contains the minimum informal testing that must be conducted as appropriate for a given system.

E. The department may require additional formal compliance testing or informal testing, or both, as necessary to protect public health and the environment. Additional testing shall be based on observed problems and shall not be implemented routinely on all discharging systems.

1. Anytime a discharging system is found to be out of compliance with the effluent limitations of the General Permit, follow-up formal compliance testing shall be repeated between 45 and 90 days after the original samples were collected and the results reported to the local health department. Prior to resampling, the operator should attempt to determine the reason for the noncompliance and take corrective actions.

2. Anytime an informal test reveals a potential problem, additional formal or informal testing may be conducted to review the effectiveness of any repairs or adjustments.

3. Anytime the results of two consecutive formal compliance tests as specified in subdivision C 2 or D 1 of this section result in a violation of the effluent limitations of the General Permit, informal testing shall revert to monthly frequency until satisfactory results are obtained for six consecutive months. Nothing in this section shall preclude requiring the collection of samples for formal compliance testing as described in subdivisions C 2 and D 1 of this section to determine compliance with the effluent limitations set forth in the General Permit.

F. The owner of each system is responsible for ensuring that the collection, analysis, and reporting of all effluent sample tests are completed in a timely fashion and in accordance with this section and 12VAC5-640-510. The department shall conduct an annual inspection and may conduct additional inspections at its discretion. Furthermore, the department may conduct or mandate formal or informal testing as deemed appropriate. If a system is in compliance three consecutive years, the department may reduce the department inspection frequency to a three-year cycle. Annual inspections by the department will resume if the department receives evidence that the system is out of compliance. Compliance for the purposes of this section is compliance with the testing, inspection, effluent limits, and reporting requirements of this chapter. Inspection by the department does not substitute for the required operation, maintenance, testing, and reporting requirements in 12VAC5-640-490, 12VAC5-640-500, and 12VAC5-640-510.

TABLE 3.3 INFORMAL (PROCESS CONTROL) TESTING
Treatment Unit	Informal Tests
Septic tank/trash tank	Sludge depth
Suspended growth biological treatment unit	Dissolved oxygen, settleabilty, pH, odor
Fixed film biological treatment unit	Dissolved oxygen (effluent from unit), pH, odor
Chlorine disinfection/dechlorination	TRC at end of contact tank (>1.0 mg/l), TRC after dechlorination
Ultraviolet disinfection UV	Turbidity prior to UV
Final effluent	Dissolved oxygen, pH, odor, color

Section 490. Monitoring

Statutory Authority