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Septic Technical Guidance Committee

The Technical Guidance Committee (TGC) is responsible for maintaining the Technical Guidance Manual, reviewing best management practices for individual and subsurface sewage disposal, and providing recommendations on variances and commercially manufactured wastewater treatment components and systems. The TGC comprises six members: one DEQ representative (chair), three health district representatives, one State of Idaho-licensed professional engineer, and one licensed installer. TGC meetings occur quarterly unless, a special issue warrants a special meeting.

The Technical Guidance Manual provides guidance on the design, construction, alteration, repair, operation, and maintenance of standard individual and subsurface sewage systems, their components, and alternatives. The manual is updated periodically to adapt to the dynamic and complex nature of small wastewater disposal systems. Updates are cited below.

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Current Updates to the Manual

September  2023

Section 4.20 RV Dump Station

Section 5.9 Pipe Material for Specified Uses

June 2023

Section Modified or Custom Septic Tank Approvals

Section 1.8 Property Access and Use

Section 3.2.8 Drainfield Excavation Backfilling Materials

Section 3.3 Wastewater Flows

Section 4.3.3 Above-grade Capping Fill System Approval Conditions

March 2023

Section 5.2 Approved Septic Tanks

Section 5.4 Extended Treatment Package Systems

Section 5.13 Proprietary Wastewater Treatment Products

Section 4.3.5 Capping Fill System Construction

Previous Updates to the Manual

December 2022

Section 4.2 At-Grade Soil Absorption System

Section 4.3 Capping Fill System

Section 4.24 Sand Mound

September 2022

Section Initial Septic Tank Approvals

Section Gravelless Product Approvals

Section Reduction to Separation Distance to Surface Water without a Variance

June 2022

Section 4.20 Recreational Vehicle Dump Station

February 2022

Section 2.1.2 Soil Design Groups and Subgroups

Section Reduction in Separation Distance to Surface Water without a Variance

Section 4.12 Grey Water Sump

Section 4.15 Wastewater Incinerator 

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Onsite Wastewater Coordinator

Peter Adams
(208) 954-1438

ver: 3.5.1 | last updated:
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