§ 4.84.180. Cumulative impacts and areas of environmental concern.

a.

Cumulative impacts mean persistent and/or increasing effect of OWTS resulting from the density of such discharges in relation to the assimilative capacity of the local environment. Examples include, but are not limited to, nitrate or salt additions to ground water or surface water and rise in groundwater levels (mounding of the water table) that interferes with the performance of an OWTS, causing drainage problems or resulting in other adverse hydrological or soil conditions affecting public health, water quality or public safety.

b.

Where OWTS may have cumulative impacts on groundwater and/or watershed conditions due to such factors as the constituent levels (e.g., nitrogen content) in the wastewater, the volume of wastewater flow, the density of OWTS discharges in a given area, and/or the sensitivity and beneficial uses, as defined in the CRWQCB Basin Plan, of water resources in the discharge area, Environmental Health may require additional technical studies (also termed "cumulative impact studies") or other information demonstrating, to the satisfaction of Environmental Health, that use of the proposed OWTS will not create adverse cumulative effects on water quality, public health or safety. Such cumulative impact studies will be as prescribed in the Onsite Systems Manual.

c.

Based on results of cumulative impact evaluations or consideration of factors affecting OWTS placement and performance, including, but not limited to, area-wide soil and drainage characteristics, flooding and seasonal water table, developmental density, and proximity to surface water, the Board of Supervisors may establish impaired areas. Such impaired areas shall have clear geographical boundaries, be established by Resolution after a public hearing before the Board of Supervisors, and may require additional protections related to OWTS design, installation, and reporting consistent with this chapter and Onsite Systems Manual.

(Ord. No. 04754, § 1, 1-5-2016)