Every septic system installation, repair, or expansion in Idaho requires a permit from your local health district . This page helps you find the right application forms and understand the permit process.
🏠 New Home Construction
New Septic System Permit
Installing a septic system for:
New house construction
Lot without existing system
Replacing completely failed system
Most Common Application
🔧 Repair or Upgrade
Repair Permit
Fixing or improving existing system:
Drainfield repair or replacement
Septic tank replacement
Adding treatment components
System upgrade or expansion
Second Most Common
🏘️ Adding to Existing
Expansion or Accessory Use
Adding capacity to existing system:
Home addition or extra bathroom
ADU (Accessory Dwelling Unit)
Garage apartment
Connecting to existing system
Growing in Popularity
🔍 Pre-Purchase Evaluation
Speculative Site Evaluation
Assessing feasibility before purchase:
Vacant lot evaluation
Buildability determination
System location planning
Property due diligence
Wise Investment (~$200-500)
Not sure which district you're in? Use the interactive county map to find your health district.
Quick Links by District:
When Required:
All new septic system installations
New home construction
Lots without existing systems
Replacement of completely failed systems
What You'll Need to Submit:
Completed Application Form
Property owner information
Site address and legal description
Proposed system type and size
Installer information
Site Plan (Plot Plan)
Property boundaries with dimensions
Proposed house location
Well locations (yours and neighbors' within 100 feet)
Septic system components (tank, drainfield, replacement area)
All setback distances labeled
North arrow and scale
Soils Information
Percolation test results (if required)
Soil profile descriptions
Depth to limiting layer (bedrock, water table)
Site evaluation report (if required)
Permit Fee
Varies by district ($94-$500+ typical range)
See fee schedules for district-specific costs
Processing Time:
Simple residential: 1-3 weeks
Complex sites or systems: 3-6 weeks
Incomplete applications: delayed until information provided
When Required:
Drainfield is saturated or failing
Septic tank is cracked or damaged
System upgrade needed for home expansion
Converting to alternative system type
What You'll Need:
Repair Application Form
Existing system description
Nature of failure or problem
Proposed repair method
Installer information
Site Information
Location of existing system
Available replacement area
Soil conditions
Any site constraints
As-Built Drawings (if available)
Original system installation plans
Helps identify system location
May not exist for older systems
Repair Challenges:
Limited space: Replacement area may be unavailable (built over, too close to well, etc.)
Alternative systems: May require upgrade to ATU, mound, or other technology
Higher costs: Repairs often more expensive than initial installation
Cost Range: $3,000-$20,000+ depending on complexity
When Required:
Adding bedrooms or bathrooms
Home addition increasing square footage
Installing ADU (Accessory Dwelling Unit)
Converting garage to living space
Connecting additional building to existing system
System Sizing:
Idaho systems are typically sized by bedroom count , not actual occupancy.
3-bedroom home: 450-900 gallons/day design flow
Each additional bedroom: +150 gallons/day
Key Questions:
Does existing system have capacity for additional flow?
Is existing drainfield adequate size?
Is replacement area still available?
Do setbacks still meet current requirements?
Possible Outcomes:
✅ Approved as-is: Existing system adequate
⚠️ Drainfield expansion required: Add additional trenches
🔄 Complete replacement needed: Existing system inadequate
🚫 Denied: Site constraints prevent expansion
Purpose:
Get professional assessment of septic system feasibility before purchasing property.
Why It Matters:
Property might not be buildable - Some lots can't support septic systems
Costly surprises - Alternative systems can add $10,000-$20,000 to construction
Lot value - Buildable certification increases property value
Loan requirements - Some lenders require septic feasibility confirmation
What You Get:
Soil evaluation (texture, depth, permeability)
Groundwater assessment
Site suitability determination
Recommended system type and location
Estimated system cost
Written report (usually valid 2-5 years)
Cost: $200-$800 depending on district and complexity
Who Can Perform:
Health district staff (some districts)
Licensed engineers
Certified soil scientists
Best Practice for Property Buyers:
Include speculative evaluation as contingency in purchase offer. If site won't support septic, you can walk away or renegotiate price.
Northern Idaho Applications
Counties: Benewah, Bonner, Boundary, Kootenai, Shoshone
Available Forms:
Septic System Permit Application (June 2025)
Repair/Expansion Application
Speculative Site Evaluation Form
⭐ Mortgage Survey Application (unique to this district)
Unique Features:
Mortgage Survey Application - For real estate transactions requiring well/septic inspection
Real estate focus with specialized forms
May-June 2025 updates (recent forms)
Fee Schedule: FY2023 Environmental Health Fees
View Panhandle Resources →
North-Central Idaho Applications
Counties: Clearwater, Idaho, Latah, Lewis, Nez Perce
Available Forms:
Individual Sewage Disposal System Permit (2025)
Site Evaluation Form
Repair/Modification Application
Variance Petition Form
Final/As-Built Inspection Form
Unique Features:
Most comprehensive training materials - 98-page basic + 63-page complex installer guides
DEQ statewide resources - Technical Guidance Manual (350 pages), approved products database
85 technical diagrams extracted from training materials
Fee Schedule: February 2025 Environmental Health Fee Schedule
View North Central Resources →
Western Idaho Applications
Counties: Adams, Canyon, Gem, Owyhee, Payette, Washington
Available Forms:
Individual Sewage System Application
Repair Permit Application
Subdivision Applications
Speculative Site Evaluation
Unique Features:
Subdivision engineering expertise - SER templates and sanitary restriction language
Well water quality resources - Hydrogen sulfide guidance
Emergency procedures - Sewage cleanup protocols
Applications: Online portal system
View Southwest Resources →
Boise Metro Applications
Counties: Ada, Boise, Elmore, Valley
Available Forms:
County-specific applications:
Ada/Boise County Application (most urban)
Elmore County Application
Valley County Application
Repair/Expansion Applications
Accessory Use Applications
Speculative Site Evaluation
Planning & Zoning Review Form
Unique Features:
⭐ Lawful Presence Verification (new July 2025 requirement)
County-specific forms - Different applications for different counties
Highest permit fees - $94-$1,505 (urban services)
ATU focus - Aerobic treatment common for small urban lots
Fee Schedule: Detailed fee matrix by service type
View Central District Resources →
South-Central Idaho Applications
Counties: Blaine, Camas, Cassia, Gooding, Jerome, Lincoln, Minidoka, Twin Falls
Available Forms:
Septic System Permit Application
Repair Permit Application
Subdivision Application
Site Evaluation Request
Unique Features:
⭐ May 2025 Rule Changes - Most recent regulatory updates
Gravelless systems guidance - Emerging technology (May 2025)
Acreage policies - Policies 795/799 for lot size requirements
2025 Installer Course - 20 MB comprehensive training
Fee Schedule: Included in collection
View South Central Resources →
Southeastern Idaho Applications
Counties: Bannock, Bear Lake, Bingham, Butte, Caribou, Franklin, Oneida, Power
Available Forms:
Individual Sewage Disposal Permit Application (Sept 2025)
Installer Application (Sept 2025 - most recent!)
Pumper Application
Speculative Evaluation Form
Subdivision Application
Unique Features:
⭐ RCAC Grant Funding Info - Financial assistance for low-income homeowners (unique!)
Soils education - Soils/wastewater relationships factsheet
Groundwater monitoring - Well installation procedures
Most recent installer app - September 2025
Fee Schedule: Included in collection
View Southeastern Resources →
⭐ Most Current Forms
Counties: Bonneville, Clark, Custer, Fremont, Jefferson, Lemhi, Madison, Teton
Available Forms:
⭐ Septic Permit Application (June 2025) - Most current permit app
Installer Application (July 2025)
Pumper Application (July 2025)
Speculative Evaluation Form (Feb 2025)
Connect to Existing System Form
Letter of Intended Use (non-residential)
Unique Features:
⭐ MOST CURRENT IN ENTIRE KNOWLEDGEBASE - October 2025 homeowner guide
DIY Homeowner Focus - Comprehensive installation manual for homeowner-installers
Current approved materials - Sept 2025 aggregate list
June-October 2025 updates - Newest forms across the board
Fee Schedule: Available from district
View Eastern Idaho Resources →
District Typical Residential Permit Speculative Evaluation Repair Permit Panhandle See FY2023 fee schedule $200-500 Varies North Central See Feb 2025 fee schedule $200-400 Varies Southwest Check online portal $200-500 Varies Central (CDH) $94-$1,505 $250-500 $94-$750 South Central See fee schedule $200-400 Varies Southeastern See fee schedule $200-400 Varies Eastern Idaho See district $200-500 Varies
Detailed fee information: Fees & Financial Assistance →
Before you submit:
✅ Determine project type (new, repair, expansion)
✅ Find your health district
✅ Download current application forms
✅ Review separation distance requirements
✅ Check if speculative evaluation needed
✅ Budget for permit fees + installation costs
Property Information:
Legal description (from deed or tax records)
Lot size and dimensions
Existing structures and utilities
Well locations (yours and neighbors')
Site Conditions:
Soil type and characteristics
Topography (slopes, drainage)
Groundwater depth
Obstacles (rock outcrops, trees, easements)
System Design:
House size and bedroom count
Estimated wastewater flow
Proposed system type
Tank and drainfield locations
Required Elements:
Property boundaries with dimensions
Proposed or existing buildings
Septic system components (tank, drainfield, replacement area)
Wells within 100 feet (including neighbors')
Surface water bodies
All setback distances labeled
North arrow
Scale (e.g., 1" = 20')
Tools:
Graph paper for hand-drawing
CAD software for professional plans
Hire surveyor for complex sites
Use satellite imagery as base layer
Site Plan Tips
Measure carefully - Mistakes delay approval
Show replacement area - 100% required, must meet setbacks
Label everything - Don't make reviewers guess
Include legend - Explain symbols and abbreviations
Professional presentation - Neat, legible plans get faster approval
Common Sections:
Property owner contact information
Site address and legal description
Lot size and dimensions
Number of bedrooms
Type of system proposed
Installer information (if known)
Signature and date
Accuracy Matters:
Double-check all information
Use legal property description (not street address)
Provide daytime phone and email
Sign and date application
What to Include:
✅ Completed application form (original signature)
✅ Site plan showing all required information
✅ Soils information (perc tests, evaluation reports)
✅ Permit fee (check or credit card)
✅ Additional documents (variance petitions, engineering reports if needed)
Submission Methods:
In person: Most districts accept walk-in applications
Mail: Certified mail recommended for proof of delivery
Online: Some districts have online portals
Email: Check if district accepts electronic submissions
Get Receipt:
Always get dated receipt confirming application received. This starts the processing clock.
What Happens:
Health district staff reviews application for completeness
Site conditions evaluated against regulations
Setbacks verified
System design checked for adequacy
Soils assessed for suitability
Possible Outcomes:
✅ Approved - Proceed with installation
⚠️ Additional information requested - Provide missing data
🔄 Modifications required - Revise design and resubmit
🚫 Denied - Site unsuitable or doesn't meet requirements
Timeline:
Simple residential: 1-3 weeks
Complex or alternative systems: 3-6 weeks
Variances or special circumstances: 6-12 weeks
What You Receive:
Approved permit document
Approved site plan (stamped)
Installation requirements and conditions
Inspection schedule
Permit expiration date (typically 2-5 years)
Next Steps:
Hire licensed installer (if not already arranged)
Schedule installation
Notify health district of start date
Arrange required inspections
Required Inspections:
Most districts require multiple inspections :
Pre-installation: Verify site conditions before digging
Tank installation: Inspect tank placement and connections
Drainfield construction: Inspect before backfilling
Final inspection: Verify complete installation
Inspection Process:
Call district to schedule (24-48 hours advance notice)
Inspector visits site
Must pass each stage before proceeding
Failed inspection = stop work, make corrections, re-inspect
Don't Backfill Before Inspection
NEVER cover drainfield before final inspection. If inspector sees problems, you'll dig it all up again at your expense. This is the most common and costly mistake.
What's Required:
All inspections passed
System installed per approved plans
As-built drawings submitted showing actual locations
Final fees paid (if applicable)
As-Built Drawings:
Document actual installed locations (may differ slightly from plan):
Septic tank location with dimensions from permanent reference points
Drainfield boundaries and dimensions
Access risers and manholes
Any deviations from original plan
Why As-Builts Matter:
Future repairs require knowing exact locations
Property transfers need system documentation
Protects your investment with permanent record
Ongoing Requirements:
Pump septic tank every 1-3 years
Maintain repair/replacement access
Don't build over replacement area
Keep maintenance records
Some alternative systems require annual service reports
Selling Property:
Provide buyers with:
Approved permit documents
As-built drawings
Pumping and maintenance records
Warranty information (if applicable)
Do:
✅ Start early - Permitting takes time
✅ Ask questions - District staff are there to help
✅ Submit complete applications - Saves time and frustration
✅ Hire professionals for complex situations
✅ Keep copies of everything you submit
Don't:
❌ Assume property is buildable without evaluation
❌ Start work before permit approved
❌ Guess at measurements or setbacks
❌ Submit sloppy, incomplete applications
❌ Argue with inspector (ask for clarification instead)
Before You Buy:
Request speculative site evaluation as purchase contingency
Review existing system documentation (if present)
Verify replacement area hasn't been built over
Check if lot size meets minimum requirements
Confirm adequate setbacks from property lines and wells
Red Flags:
🚩 Seller refuses septic evaluation contingency
🚩 No documentation of existing system
🚩 Buildings or improvements over replacement area
🚩 Very small lots (may not meet current setbacks)
🚩 High groundwater or rocky soils visible
Can You Install Your Own System?
Idaho allows homeowner installation on your primary residence if you:
Own the property
Will occupy the home
Obtain proper permits
Pass all inspections
Meet all regulatory requirements
Resources:
Realistic Assessment:
Pros: Save $3,000-$8,000 in labor costs
Cons: Physically demanding, must rent equipment, risk of mistakes, no warranty
When to Hire Pro:
Alternative systems (ATUs, mounds, pressure distribution)
Difficult sites (slopes, rock, high water table)
You lack time, tools, or physical ability
Any system with mechanical components
Not sure which form you need? Contact your local health district:
Or find your county on the interactive map .
New System Permit - New construction or replacing failed system
Repair Permit - Fixing or upgrading existing system
Speculative Evaluation - Pre-purchase property assessment
Permit fees: $94-$500 (residential)
Speculative evaluation: $200-$500
Site plan preparation: $0-$500 (DIY to professional)
Total installation: $5,000-$30,000+ depending on system type
Application review: 1-6 weeks
Installation: 1-3 days (simple) to 1-2 weeks (complex)
Inspections: Multiple site visits throughout installation
Permit expiration: 2-5 years (varies by district)
🚩 Incomplete applications
🚩 Inaccurate measurements or missing setbacks
🚩 Illegible site plans
🚩 Insufficient replacement area
🚩 Soil conditions not evaluated
🚩 Variance needed but not requested
Septic permits protect public health and groundwater quality. Complete, accurate applications get faster approvals. When in doubt, ask your health district staff - they want you to succeed!