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 2 - Design Requirements › Section 12VAC5-640-440 - Special factors affecting system design

Current through Register Vol. 40, No. 24, July 15, 2024
Each type of discharging system has its own unique
						advantages and disadvantages. These unique characteristics define the
						situations where a system may be used to advantage. The design of the system
						must be appropriate for the intended use and the site conditions where the
						system is to be installed. Subdivisions 1 through 6 of this section contain a
						list of factors that will require special design consideration. This list
						should not be considered all encompassing. There may be other design factors
						that require special consideration. A preliminary engineering conference may be
						scheduled with the department to discuss such factors prior to submitting
						designs for department review.
1. When
					 a discharge is proposed to a wetland, dry ditch, or intermittent stream,
					 restricted access to the wetland, dry ditch, or intermittent stream in
					 accordance with
					 12VAC5-640-450 to protect public
					 health.
2. Intermittent use for the
					 purposes of this chapter constitutes use of the system for less than three
					 consecutive months. Systems serving weekend cottages or other intermittent uses
					 require special design, operation, and maintenance consideration.
3. When a discharging system is proposed to
					 be located in an area subject to infiltration by surface water or shallow
					 groundwater, the department may require additional protection from
					 infiltration, inflow, and flotation, including placement of the system above
					 natural grade.
4. Erosion must be
					 controlled by the owner of the discharging system in accordance with any local
					 erosion control ordinances.
5. All
					 systems shall normally be designed to treat the BOD5
					 loading rate of 0.4 lbs/day per bedroom and a flow of 150 gallons per day per
					 bedroom for systems up to three bedrooms. Systems serving single family
					 dwellings having more than three bedrooms shall be permitted and designed to
					 treat the anticipated loading rate based on BOD5 and be
					 capable of handling anticipated peak loading and flow rates. All systems shall
					 be designed to operate over the range of anticipated flow and loading rates.
					 When a system is permitted with a design less than the maximum capacity of the
					 dwelling, the owner shall have the construction permit recorded and indexed in
					 the grantor index under the owner's name in the land records of the clerk of
					 the circuit court having jurisdiction over the site of the discharging
					 system.
6. All system designs must
					 include protection of the components from freezing or other adverse weather
					 conditions and ensure that the system will function properly year
					 round.
Statutory Authority: §§ 32.1-12 and 32.1-164
						  of the Code of Virginia.