12 Va. Admin. Code § 5-640-440
Current through Register Vol. 41, No. 6, November 4, 2024
Section 12VAC5-640-440 - Special factors affecting system design 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.12 Va. Admin. Code § 5-640-440
Derived from VR355-34-400 §3.6, eff. July 30, 1992; Amended, Virginia Register Volume 32, Issue 06, eff. 12/16/2015. Statutory Authority: §§ 32.1-12 and 32.1-164 of the Code of Virginia.