Department of
Environmental Quality

Note: Based on changes to section numbers and page numbers it is recommended to update and replace all of Section 4 of the Technical Guidance Manual.

2015

Description

December

Section 1.4.2.2. Extended Treatment Package System Approvals. Updated policy for extended treatment package systems approval and creation of two-tiered product approval process. (pp. 1-6 - 1-8)

Section 1.4.2.4. and 1.4.2.5. Proprietary Wastewater Treatment Product Approval Policy and All Other Product Approvals. Added new policy for proprietary wastewater treatment products approval and made a heading change. (pp. 1-8 - 1-9)

Section 5.4. Extended Treatment Package Systems. Revised table and created a new table to reflect the product approved as provisional and general ETPSs respectively. (p. 5-13 - 5-18)

Section 5.5-5.12. Composting Toilets through Frainfield Remediation Components. Added new table heading numbers. (pp. 5-19 - 5-28)

Section 5.13. Total Nitrogen Reduction Approvals. Moved table from this section to replace section 8.6. (p. 5-29)

Section 5.14. Propriety Wastewater Treatment Products. Added new section and table to list products approved as proprietary wastewater treatment products. (p. 5-30)

Section 8.1. Individual/Subsurface Sewage Disposal Rules (IDAPA 58.01.03). Made a non-substantive change to wastewater flow table. (p. 8-13)

August

Section 1.4.2.3 and 1.5. Gravelless System Product Approvals and Installer's Registration Permit. Added new policy for gravelless trench product approval and at-grade soil absorption system to list of systems requiring a PE's design. (p. 1-7)

Section 2.2.5 and 2.2.5.2. Method of 72 to Determine Effective Soil Depths and In-Trench Sand Filters and the Method of 72. Updated Method of 72 to include determination of effective soil depths to impermeable layers. (p. 2-10 and p. 2-12)

Section 4.1. General Requirements. Added new guidance addressing the requirement for a PE to design all public systems per Idaho Code 54-1218. (p. 4-1)

Section 4.1.3. Multiple Alternative Systems Combined into One System. Added at-grade soil absorption system to Table 4-1. (pp. 4-6 and 4-7)

Section 4.2. At-Grade Soil Absorption System. Added new guidance for the design, construction, and installation of at-grade soil absorption systems. (pp. 4-8 - 4-17)

Section 4.3. Capping Fill System. Revised capping fill systems guidance. (pp. 4-18 - 4-20)

Section 4.23. In-Trench Sand Filter. Revised in-trench sand filters guidance. (pp. 4-133 - 4-138)

June

Section 2.5.2.1. Permanent Monitoring Wells. Updated design parameters for permanent monitoring wells. (p. 2-20)

Section 3.2.8.1.4. Pit Run. Amended sizing specifications for pit run material. (pp. 3-17 - 3-18)

Section 4.1.3. Multiple Alternative Systems Combined into One System. Added guidance addressing the combination of multiple alternative system designs into one system design. (pp. 4-3 - 4-6)

Section 4.9. Floating Vault Toilets and Boat or Vessel Sewage Disposal. Added guidance addressing design, construction, and operation/maintenance of floating vault toilets and requirements for vessel sewage disposal. (pp. 4-60 - 4-63)

Section 4.12.4. Other Requirements. Changed format in Tables 4-10 and 4-11. (pp. 4-70 - 4-71)

Section 4.20.5. Drainfield Trenches. Added hydraulic application rate for A-2a and A-2b soils to Table 4-18. (p. 4-112)

Section 4.21.4. Drainfield Trenches. Added hydraulic application rate for A-2a and A-2b soils to Table 4-20. (p. 4-118)

Section 5.2. Approved Septic Tanks. Changed Infiltrator Systems, Inc. to Infiltrator Water Technologies, LLC (p. 5-4)

Section 5.3. Approved Dosing Chambers. Changed Infiltrator Systems, Inc. to Infiltrator Water Technologies, LLC (p. 5-11)

Section 5.4. Extended Treatment Package Systems. Added Norweco TNT ETPS model. (p. 5-16)

Section 5.7, Gravelless Trench Components. Changed Infiltrator Systems, Inc. to Infiltrator Water Technologies, LLC (pp. 5-20 - 5-21)

Section 5.12. Drainfield Remediation Components. Changed Infiltrator Systems, Inc. to Infiltrator Water Technologies, LLC (p. 5-27)

Section 8.1. Individual/Subsurface Sewage Disposal Rules (IDAPA 58.01.03). Revised IDAPA 58.01.03.005.11 to reference correct Idaho code (p. 8-9)

April

Section 1.6. Nonprofit Corporations. Moved from Section 4. No content changed. (pp. 1-10 - 1-13)

Section 1.7. Existing and Approved Systems, Abandoned and Undocumented Systems, and Nonconforming Systems. Replaced entire section to provide clarification on different system classifications, their allowed use, and permit requirements. Moved from Section 4. (pp. 1-13 - 1-16)

Section 1.8. Easement. Moved from Section 4. No content changes. (pp. 1-16 - 1-17)

Section 2.1.3. Soil Design Subgroup Corrections. Made subgroup corrections optional at the discretion of the permitting health district and provided an example of how subgroup corrections are made. (p. 2-6)

Section 4.15. Pit Privy. Updated to include new construction and maintenance standards. (pp. 4-74 - 4-75)

Section 4.16. Portable Sanitation Units. Updated to include new construction and maintenance standards and unit requirements based on event use and event attendance. (pp. 4-76 - 4-78)

Section 4.26. Vault Privy. Added new construction and maintenance standards. (pp. 4-137 - 4-138)

Section 5.2. Approved Septic Tanks. Corrected a tank description for Infiltrator Systems, Inc. (p. 5-4)

March

Section 3.2.8.1.2. Medium Sand. Corrected an error in the percentage of material passing the #30 sieve for medium sand. (p. 3-17)

Section 5.2. Approved Septic Tanks. Added Infiltrator Systems, Inc. 475-gallon and 1,500-gallon septic tank. (p. 5-4)

Section 5.3. Approved Dosing Chambers. Added Infiltrator Systems, Inc. 552-gallon dosing chamber. (p. 5-11)

January

Section 4.22.5. Drainfield Trenches. Corrected label in Figure 4-27. (p. 4-110)

2014

Description

December

Section 1.4.2.1.1. Initial Septic Tank Approvals. Added description of the approval process for new septic tank models for manufacturers. (pp. 1-3 -1-5)

Section 1.4.2.1.2. Transfer of Septic Tank Approvals Between Manufacturers. Added description about the process a manufacturer must complete to transfer approval of an existing septic tank model from another manufacturer to the new manufacturer's approved list. (p. 1-5)

Section 3.2.3. Septic Tanks and Dosing Chambers. Updated installation requirements for septic tanks and dosing chambers and removed design criteria that was included in section 1.4.2.1.1. (pp. 3-5 - 3-8)

Section 4.10.3. Extended Treatment Package System Operation, Maintenance, and Monitoring. Updated to include an allowance of sampling from a common dosing chamber for multiple systems from the same manufacturer. (pp. 4-43 - 4-47)

Section 4.11. Extra Drainrock Trench. Updated to amend approval conditions and multiplication factors used in the extra drainrock trench design. (pp. 4-58 - 4-63)

Section 4.16. Incinerator Toilets. Updated to amend approval conditions, design, and operation and maintenance requirements for incinerator toilets. (pp. 4-75 - 4-76)

Section 4.22. Recirculating Gravel Filter. Updated to amend approval conditions, design, construction, inspection, and operation and maintenance requirements for recirculating gravel filter systems. (pp. 4-102 - 4-112)

Section 4.23. Intermittent Sand Filter. Updated to amend approval conditions, design, construction, inspection, and operation and maintenance requirements for intermittent sand filter systems. (pp. 4-113 - 4-119)

Section 4.24. In-Trench Sand Filter. Updated to reflect new figure numbers. (pp. 4-120 - 4-124)

Section 4.25. Sand Mound. Updated to reflect new figure numbers. (pp. 4-125 - 4-135)

Section 4.27. Steep Slope System. Updated to amend approval conditions and construction requirements for steep slope systems. (pp. 4-138 - 4-139)

Section 4.28. Two-Cell Infiltrative System. Updated to reflect new figure numbers. (pp. 4-140 - 4-142)

Section 5.7. Gravelless Trench Components. Updated to reflect the new approval of Infiltrator Systems, Inc.'s Arc 36 LP gravelless chamber product. (p. 5-19)

Section 6.1. Septic Tank Pumping and Septage Disposal. Updated throughout to describe current septic tank pumping recommendations, describe septage classification, permit requirements, and septage storage and disposal. (pp. 6-1 - 6-10)

November

Section 4.2.1. Required Nonprofit Incorporation Elements. Corrected cross-reference number for Line 23. (p. 4-5)

Section 5.2. Approved Septic Tanks. Clarified bury depths for tanks only listed as HS20 load rated. (p. 5-10)

Section 5.7. Gravelless Trench Components. Corrected product ownership and model names. (pp. 5-19 and 5-20)

October

Section 1.5 Installer Registration Permit. Guidance added on what is required to obtain an installer's registration permit and requirements necessary to renew the permit. (pp. 1-4 - 1-7)

Section 2.2.4.2.3 Nutrient Evaluation Model Outputs for a Reduced Separation Distance to Surface Water. Clarified site life requirements. (p. 2-10)

Section 3.2.3.1 Conversion of a Septic Tank to a Lift Station. Guidance added on recommended practices for the conversion of a septic tank to a lift station. (pp. 3-7 - 3-8)

Section 4.1 General Requirements. Added description of plan requirements, operation and maintenance documents, and as-built plans and specifications for engineering of subsurface sewage disposal systems. Description of plumbing and electrical permit requirements for subsurface sewage disposal systems also added. (pp. 4-1 - 4-3)

Section 4.7.7 Drip Distribution. Corrected error in system design example. (p. 4-21)

Section 4.17 Individual Lagoon. Updated requirements for design, installation, and operation and maintenance of an individual lagoon. (pp. 4-73 - 4-76)

Section 4.20.3.2 Pressure Distribution. Revised equation number. (pp. 4-86 - 4-87)

Section 4.25.3.2 Sand Mound. Revised equation number. (p. 4-114)

Section 5.2 Approved Septic Tanks. Added new 1,000 gallon Wilbert Precast, Inc. septic tank to Table 5-1. (p. 5-10

August

Section 4.25.3.2 Sand Mound - Medium Sand Fill Design. Table 4-22 corrected to reflect correction factor for 20% slope. (p. 4-111)

June

Section 2.1.4 Medium Sand. Section removed and replaced with section 3.2.8.1.2.

Section 2.2 Separation Guidelines. Revised to include provisions for the reduction in the separation distance to surface water from a drainfield with and without the use of a variance. (pp. 2-7 - 2-13)

Section 3.2.7 Drainfield Cover. Updated to provide further clarification for both soil barriers and soil cover over drainfields. (pp. 3-13 - 3-17)

Section 3.2.8 Drainfield Excavation Backfilling Materials and Alternative System Construction Media. Added to provide descriptions on what backfilling materials are allowed for use in drainfields, how drainfield aggregate and construction media sources must be approved, the specifications for the various aggregate and construction media, and the process to substantiate aggregate and construction media sources and volumes. (pp. 3-13 - 3-17)

Section 4.5 Capping Fill System. Updated to provide clarification in the construction techniques used depending on the installation depth of the drainfield. (pp. 4-9 - 4-11)

Section 4.7 Drip Distribution. Updated to provide a revision in section formatting and clarification of required system components. (pp. 4-14 - 4-22)

Section 4.9 Experimental System. Updated to clarify approval conditions and add recommendations on operation and maintenance requirements. (pp. 4-39 - 4-40)

Section 4.10.3 Extended Treatment Package System Operation, Maintenance and Monitoring. Updated to include additional effluent testing methods, extend the deadline for resampling upon initial effluent sampling failure, and include regulatory provisions for property owners that fail to resample upon initial sample failure. (pp. 4-44 - 4-45)

Section 4.10.8 Extended Treatment Package System Construction. Updated to include the requirement that the O&M entity or service provider will submit information on the manufacturer, product, model number, and serial number of each ETPS installed prior to health districts providing final approval of the system installation. (p. 4-55)

Section 4.20 Pressure Distribution System. Updated throughout to meet the most current design research on pressure distribution systems. (pp. 4-78 - 4-92)

Section 4.25 Sand Mound. Updated throughout to meet the most current design research on sand mounds. (pp. 4-108 - 4-118)

Section 4.28 Two-Cell Infiltrative System. Updated to include revisions to construction, inspection, and operation and maintenance requirements. (pp. 4-122 - 4-124)

Section 5.2 Approved Septic Tanks. Jerome Precast was purchased by Triple C Concrete and is in the process of transferring approval for Jerome Precast's existing models. (pp. 5-4 - 5-9)

Section 5.3 Approved Dosing Chambers. Maximum bury depth included for each dosing chamber. (p. 5-11)

May

Section 5.2 Approved Septic Tanks. Added a new 1,000 gallon septic tank with an integral 500 gallon dosing chamber and a 1,500 gallon septic tank for Kanta Products, Inc. Additional descriptions of bury depths and updated material descriptions provided for all previously approved septic tanks. (pp. 5-2 - 5-10)

Section 5.3 Approved Dosing Chambers. Updated table format and headings. (p. 5-11)

Section 5.11 Vault Toilets. Added two vault toilet manufacturers that were previously listed in the approved septic tank list. (p. 5-25)

Section 8. Updated subsurface rules to include non-substantive revisions to IDAPA 58.01.03.005.16 and 58.01.03.006.07. (pp. 8-9 - 8-10)

March

Section 4.4 Easement. Revised section covering the creation of an easement for the placement of a subsurface sewage disposal system on a property that does not contain the wastewater generating structure. (pp. 4-7 - 4-8)

Section 4.12.2 and 4.12.3. new callout for section and table numbers. (p. 4-56)

Section 4.24. In-Trench Sand Filter. Revised section covering the design, installation, and construction of in-trench sand filters. (pp. 4-97 - 4-101)

Section 4.25. Sand Mound. New figure numbers. (pp. 4-102 and 4-104)

Section 4.27. Steep Slope System. New figure numbers. (p. 4-113)

Section 4.28. Two-Cell Infiltrative System. New figure numbers. (pp. 4-115 and 4-116)

Section 4.30. Drainfield Remediation Components. New section and table callout numbers. (p. 4-119)

Section 5. Addition of new section 5.3 listing approved dosing chambers, amended the section numbers for approved products throughout due to the addition of section 5.3, section 5.8 Pump Vaults only addresses packaged septic tank pump vault units after the removal of the approved dosing chambers to section 5.3. (p. 5-1 - 5-25)