Virginia Administrative Code
Title 9 - ENVIRONMENT
Agency 25 - STATE WATER CONTROL BOARD
Chapter 790 - SEWAGE COLLECTION AND TREATMENT REGULATIONS
Part II - Operational Regulations
Article 3 - Requirements for Sewerage Systems and Treatment Works Reliability
Section 9VAC25-790-300 - Reliability
Current through Register Vol. 41, No. 3, September 23, 2024
A. Additional operation and maintenance documentation may be necessary where performance reliability has not been established or worker safety and public health protection is questioned.
B. Operability. Independently operated essential equipment or components of sewerage systems and treatment works shall be provided with sufficient duplication or alternative operation so that the average daily design flow may be transported, stored, treated, or otherwise managed in accordance with reliability requirements with the largest component out of service. Sufficient spare parts to ensure continuous operability of essential unit operations and equipment shall be kept in a central storeroom located at the treatment works or at other readily accessible locations, and the minimum quantities shall be in accordance with the operation and maintenance manual. The need for spare parts should be determined from review of manufacturer's recommendations, evaluation of past maintenance requirements, and any other relevant factors. A spare parts inventory shall be included in the operation and maintenance manual. The inventory shall list the minimum and maximum quantities of the spare parts to be kept on hand, the equipment in which the spare parts are used, the storage location of the spare parts, replacement procedures, and other pertinent information. A suggested spare parts inventory system is contained in Part IV (9VAC25-790-940 et seq.) of this chapter.
C. Maintenance. A regular program of preventive maintenance shall be adhered to. The Operations and Maintenance Manual shall contain a system of maintenance requirements to be accomplished.
D. Personnel.
In instances where the recommended hours of attendance by a licensed operator are less than the daily hours the treatment works is to be manned by operating staff (see Table 1), a licensed operator is not required to be physically located at the treatment works site during the remaining designated manning hours, provided that the licensed operator is able to respond to requests for assistance in a satisfactory manner, as described in the Operation and Maintenance Manual.
E. Conditions. The objective of treatment works operation should be to provide the most reliable and efficient performance that can be practically achieved in compliance with permit requirements, while providing for safe working conditions. Operational health and safety provisions are critical. Cross-media pollution prevention measures should be evaluated and developed where practical, and material safety data sheets for toxic chemicals used should be readily available.
TABLE 1. CLASSIFICATION OF TREATMENT WORKS AND RECOMMENDED MINIMUM HOURS OF ATTENDANCE BY LICENSED OPERATORS AND OPERATING STAFF(1). |
||||
Treatment Works Classification & Treatment Required Classification of the Operator in Responsible Charge |
Treatment Works Capacity (MGD) |
Treatment Process Methods |
Recommended Attendance by a Licensed Operator(2,3) Time-Hrs. |
Recommended Daily Hours that Works Should Be Manned(2,3) |
I |
Greater than 10 MGD |
Biological Treatment Methods |
||
(A) Suspended Growth Reactors |
24 |
24 |
||
(B) Aerated Lagoons or Constructed Wetlands |
16 |
24 |
||
(C) Filters or Other Attached Growth Contactors |
24 |
24 |
||
(D) Processes Utilizing Biological Nutrient Control |
24 |
24 |
||
(E) Processes Utilizing Land Treatment |
During Land Application |
- - |
||
I |
Equal to or less than 10 MGD but greater than 5 MGD |
Biological Treatment Methods |
||
(A) Suspended Growth Reactors |
16 |
24 |
||
(B) Aerated Lagoons or Constructed Wetlands |
8 |
16 |
||
(C) Filters or Other Attached Growth Contactors |
16 |
24 |
||
(D) Processes Utilizing Biological Nutrient Control |
16 |
24 |
||
(E) Processes Utilizing Land Treatment |
During Land Application |
- - |
||
I |
Greater than 5 MGD |
Advanced Waste Treatment (AWT) |
||
(A) Ammonia Stripping |
24 |
24 |
||
(B) Breakpoint Chlorination |
24 |
24 |
||
(C) Carbon Adsorption |
24 |
24 |
||
(D) Chemical Coagulation, Flocculation, Precipitation |
24 |
24 |
||
(E) Filtration |
24 |
24 |
||
(F) Demineralization (Ion Exchange, Reverse Osmosis, Electrodialysis) |
24` |
24 |
||
I |
Equal to or less than 5 MGD but greater than 2.5 MGD |
Advanced Waste Treatment |
||
(A) Ammonia Stripping |
16 |
24 |
||
(B) Breakpoint Chlorination |
16 |
24 |
||
(C) Carbon Adsorption |
16 |
24 |
||
(D) Chemical Coagulation, Flocculation, Precipitation |
16 |
24 |
||
(E) Filtration |
16 |
24 |
||
(F) Demineralization (Ion Exchange, Reverse Osmosis, Electrodialysis) |
16 |
24 |
||
(G) Microstraining/Screening |
16 |
24 |
||
II |
Greater than 2.5 MGD but equal to or less than 5.0 MGD |
Biological Treatment Methods |
||
(A) Suspended Growth Reactors |
8 |
24 |
||
(B) Aerated Lagoons or Constructed Wetlands |
8 |
26 |
||
(C) Filters or Other Attached Growth Contactors |
8 |
24 |
||
(D) Processes Utilizing Biological Nutrient Control |
8 |
24 |
||
(E) Processes Utilizing Land Treatment |
During Land Application |
- - |
||
II |
Greater than 0.5 MGD but equal to or less than 2.5 MGD |
Biological Treatment Methods |
||
(A) Suspended Growth Reactors |
8 |
16 |
||
(B) Aerated Lagoons |
4 |
8 |
||
(C) Filters or Other Attached Growth Contactors |
8 |
16 |
||
(D) Processes Utilizing Biological Nutrient Control |
8 |
16 |
||
(E) Processes Utilizing Land Treatment |
During Land Application |
- - |
||
II |
Greater than 0.1 MGD but equal to or less than 2.5 MGD |
Advanced Waste Treatment |
||
(A) Ammonia Stripping |
8 |
16 |
||
(B) Breakpoint Chlorination |
8 |
16 |
||
(C) Carbon Adsorption |
8 |
16 |
||
(D) Chemical Coagulation, Flocculation, Precipitation |
8 |
16 |
||
(E) Filtration |
8 |
16 |
||
(F) Demineralization (Ion Exchange, Reverse Osmosis, Electrodialysis) |
8 |
16 |
||
III |
Greater than 0.04 MGD but Equal to or less than 0.5 MGD |
Biological Treatment Methods |
||
(A) Suspended Growth Reactors |
8 |
8 |
||
(B) Aerated Lagoons or Constructed Wetlands |
8 |
8 |
||
(C) Filters or Other Attached Growth Contractors |
8 |
8 |
||
(D) Processes Utilizing Biological Nutrient Control |
8 |
8 |
||
(E) Processes Utilizing Land Treatment |
During Land Application |
- - |
||
III |
Greater than 1.00 MGD |
Natural Treatment Methods |
4 |
8 |
III |
Greater than 0.001 MGD but equal to or less than 0.1 MGD |
Advanced Waste Treatment |
||
(A) Ammonia Stripping |
8 |
8 |
||
(B) Breakpoint Chlorination |
8 |
8 |
||
(C) Carbon Adsorption |
8 |
8 |
||
(D) Chemical Coagulation, Flocculation, Precipitation |
8 |
8 |
||
(E) Filtration |
8 |
8 |
||
(F) Demineralization (Ion Exchange, Reverse Osmosis, Electrodialysis) |
8 |
8 |
||
IV |
Greater than 0.001 MGD but equal to or less than 0.04 MGD |
Biological Mechanical Methods(4) |
4(5) |
4(5) |
IV |
Greater than 0.001 MGD but equal to or less than 1.00 MGD |
Natural Treatment Methods(4) |
4(5) |
4(5) |
Notes: (1)Specific requirements for the number of licensed operators and the number and qualifications of the operating staff specified in accordance with this chapter and in consultation with and concurrence by the director are to be evaluated on a case-by-case basis in accordance with operational reliability and permit compliance data. Such requirements are to be included in the Operation and Maintenance Manual. (2)If a particular treatment unit is discontinued or not in use for a significant period of time and the remaining treatment processes result in a lower classification for the treatment works, the licensed operator and operating staff requirements during that period may be reduced to that required for the type and classification of treatment process remaining in service, after concurrence by the director. (3)If more than one sewage treatment process is used, the more stringent requirements among the processes will apply. In some cases, complexity of operation for several AWT processes in sequence may require more than the minimum coverage. (4)Mechanical treatment processes are defined as those containing aerated and mixed flows using electrical or outside energy sources. (5)An operator is not required unless the facility is designated as a wastewater treatment works by DEQ. |
Statutory Authority: §§ 62.1-44.19 and 62.1-44.19:3.5 of the Code of Virginia