8-13D-9-33: SEWER SYSTEM:

Planning for sewage collection, treatment and reuse requires attention to several goals.

   •   Use a method of collection that is well suited to the largely rural nature of the project.

   •   Use a method of treatment and disposal that is suited to the soils, geology, and hydrogeology of the area.

   •   Use the treated wastewater in a manner that is consistent with the goal of protecting groundwater quality.

   •   Do not discharge treated wastewater to surface water.

   •   Use a system that does not depend on treatment and disposal through existing systems in Boise and Eagle.

   •   Use a system that lends itself to professional management of operations and maintenance.

Lots greater than two and a half (2.5) acres located north of the power lines will be served through individual systems with the same general processes described above.

A sewer collection network, central sewage lift station, wastewater treatment plant and treated wastewater distribution pipeline system has been built, tested and is available for service. The design, construction and operation of the system are regulated by the Idaho Department of Health and Welfare-Division of Environmental Quality (IDHW- DEQ).

   •   Planning,

   •   Preliminary, and

   •   Permitting.

The planning level of review is that which can be expected as a result of this application. Information presented in the predevelopment conditions section in this application provides a good description of the expected soils, geology, and groundwater conditions on the site. As mentioned, these findings have guided the siting of various uses. They also provide information suitable to establish general technical feasibility wastewater treatment systems and pressurized, subsurface dosing systems in the areas identified for their usage. More specific information will be required in subsequent review levels.

After this application is submitted and approved, the applicant will then proceed with preliminary design and final design for each successive phase. The initial phase preliminary design will include additional study for the area included in these phases. Typically, the preliminary study will include the following tasks:

   •   Coordinate with the Central District Health (CDH) and the Department of Environmental Quality (DEQ) to confirm the specific scope of study for both individual and community and surface disposal systems.

   •   Open soil observation pits and prepare soils logs and strategically position groundwater observation and groundwater monitoring holes.

   •   Evaluate soils, topography, and geology.

   •   Develop design, sizing, and location recommendations for all systems.

   •   Provide findings to CDH for approval.

The sewer collection network is a conventional gravity flow network of pipelines that flows to a central sewage lift station. The sewage lift station pumps the sewage to the wastewater treatment plant. The wastewater treatment plant is an aerated lagoon biological treatment system with a treated wastewater storage impoundment. The biologically treated wastewater is stored through the nongrowing season until it can be beneficially used for irrigation during the growing season. The biologically treated wastewater will be pumped from the storage impoundment through a filtration and disinfection system. The filtered and disinfected water will supply an irrigation distribution pipeline network for common area landscape and agricultural irrigation. The final treated wastewater will be applied at agronomic rates for beneficial use to maximize the reuse of the water as a resource and protect groundwater quality. The wastewater collection and treatment system are depicted on the sewer system plan.

The figure also shows the general area to be served with sewer as defined by the estimated development envelopes. Therefore, the limits of areas served by sewer may not be precisely concurrent with development areas shown in the master land use plan map, which depicts the conceptual lot boundaries.

   Figure 3-F

(Ord. 1002, 10-28-2025)