At a minimum, the SRS must include the following information:
- (1) Design flow and waste strength.
(2) A description of the physical characteristics of the primary and reserve drainfield site including:
- (a) Predominant soil type;
- (b) Vertical separation; and
- (c) Water table.
(3) Identification of sensitive or critical areas designated by a local, state, or federal agency if the primary or reserve drainfield is located within the boundaries of the area including, but not limited to:
- (a) Critical aquifer recharge area;
- (b) Sole source aquifer;
- (c) Designated wellhead protection area;
- (d) Marine recovery area; and
- (e) One hundred-year flood plain.
(4) Identification of sensitive lands or resources within one-half mile of the primary or reserve drainfield perimeter including, but not limited to:
- (a) Fish hatcheries;
- (b) Shellfish growing areas; and
- (c) Water recreation areas.
(5) Basic hydrogeology information for the primary and reserve drainfield including, but not limited to:
- (a) Well logs for all wells within one thousand feet;
- (b) Depth to groundwater including perched groundwater and deeper aquifers;
- (c) Vadose zone characteristics, including the presence of impermeable layers or aquitards;
- (d) Direction of groundwater flow;
- (e) Groundwater quality information, including nitrate and fecal coliform;
- (f) Nitrate screening balance; and
- (g) Potential hydraulic continuity to surface water.
(6) Topographic map that clearly shows site features including:
- (a) Map scale and north arrow;
- (b) Section, township, and range where project is located;
- (c) Project or property boundaries;
- (d) Location of proposed primary and reserve drainfields;
- (e) Location of areas prone to flooding including any designated one hundred-year flood plain boundaries;
- (f) Unstable areas prone to significant surface or mass erosion;
- (g) Direction of groundwater flow;
- (h) Other contaminant sources including other OSS;
- (i) Critical area boundaries or other sensitive areas listed in subsections (3) and (4) of this section;
- (j) Surface water and wetlands within one thousand feet of the proposed drainfield perimeter; and
- (k) Active and abandoned wells within one thousand feet of the proposed drainfield perimeter.
- (7) Other information the department may request to determine public health and environmental impacts from the LOSS.
[Statutory Authority: RCW 70.118B.020. WSR 11-12-035, § 246-272B-03200, filed 5/25/11, effective 7/1/11.]