Virginia Administrative Code › Title 12 - HEALTH › Agency 5 - DEPARTMENT OF HEALTH › Chapter 640 - ALTERNATIVE DISCHARGING SEWAGE TREATMENT REGULATIONS FOR INDIVIDUAL SINGLE FAMILY DWELLINGS › Part III - Location, Design, Construction, Operation and Maintenance Criteria › Article 3 - Construction Requirements › Section 12VAC5-640-470 - General construction requirements

Current through Register Vol. 40, No. 24, July 15, 2024
A. No portion of any system may be covered or
					 used until inspected, corrections made if necessary, and approved, by the
					 department or unless expressly authorized in writing by department. All
					 applicable sections contained in the Sewage Handling and Disposal Regulations,
					 12VAC5-610, shall be used to establish design and construction criteria not
					 contained in this chapter.
B.
					 Gravity sewer lines and lines between components of the system shall be
					 schedule 40 pipe and shall have a minimum grade of 1.25 inches per 10 feet for
					 three-inch and four-inch sewer lines. Discharge lines after primary or
					 secondary treatment units shall have a minimum grade of six inches per 100
					 feet. Where minimum grades cannot be maintained, detailed pump specifications
					 shall be shown on the site plan in accordance with Article 4 (12VAC5-610-598 et seq.) of Part IV
					 of the Sewage Handling and Disposal Regulations.
C. The treatment unit and all piping and
					 appurtenances shall be located in conformance with the approved plans. All
					 changes in location shall be approved by the local department prior to the
					 installation of the system.
D. All
					 pumps and appurtenances to the pump shall be installed according to the plans
					 and specifications approved by the department and referenced in the
					 permit.
E. All wiring shall be
					 approved by the local building official and shall be weather tight and
					 permanent in nature (hard wired).
F. The control panel for the system shall be
					 located within 15 feet of the treatment unit and shall be provided with a
					 manual override switch. Each pumping station shall be provided with controls
					 for automatically starting and stopping the pumps based on water level. When
					 float type controls are utilized they shall be placed so as to be unaffected by
					 the flow entering the wet well.
G.
					 All mechanical treatment units shall be provided with an alarm system on a
					 separate electrical circuit from the remainder of the treatment unit. The alarm
					 shall be both audio and visual and shall be located in an inhabited portion of
					 the dwelling. Examples of alarm conditions to be monitored include aerator
					 failure, blower failure, and high water level.
H. Except for the discharge pipe, and step
					 type post aeration if used for post-aeration, no portion of the discharging
					 system may be located in the 100-year flood plain.
I. The design must allow for sampling to
					 confirm the efficacy of the treatment process. Sampling ports shall be
					 identified on the construction documents and shall meet the following minimum
					 requirements:
1. All discharging systems
					 utilizing chlorine as a disinfectant shall be equipped with a four inch or
					 larger sampling port connected to an approved effluent collection box at the
					 chlorine contact chamber after the 30-minute or 60-minute contact time (i.e.,
					 the sampling port shall be located at the outlet end of the chamber).
2. A separate sampling port shall be required
					 after the dechlorination unit.
3.
					 The sampling location is to be identified and a port provided if needed for
					 sampling the final effluent prior to the effluent entering the discharge
					 channel.
4. Other sampling ports
					 may be required on a case-by-case basis due to the system design.