How to Find a Septic Designer (and What to Ask)
Short answer: depending on your state, a septic system is designed by a licensed onsite designer, a professional engineer, a registered sanitarian or soil scientist, or in some places a licensed installer or the owner. To find one, ask your health department for its list, check your state's licensing board, ask local installers, or browse verified designers on landplan.io's septic designers by state. Before you hire, confirm their license covers your system type and county, and ask what the price includes.
This guide covers who is allowed to design, where to look, what to ask and what you should get back.
Who designs septic systems
The rules on who may design a septic system are set by each state or province, and sometimes differ by the size or type of system. Common arrangements:
| Who | Where they commonly design |
|---|---|
| Licensed onsite (septic) designer | Many states license designers separately from installers, sometimes in tiers by system complexity |
| Professional engineer (PE) | Large, commercial or complex systems almost everywhere; any system in some states |
| Registered sanitarian / environmental health specialist | Some states allow them to design, or the health department designs |
| Soil scientist / soil evaluator | Does the soil evaluation; in some states also the design |
| Licensed installer | Some states let installers design conventional systems they install |
| Homeowner | Some states allow owners to design a simple system for their own home |
In Ontario, septic designers generally need qualification under the Building Code, and permit forms ask for the designer's BCIN (Building Code Identification Number). Other provinces have their own registration.
Your state's rules decide who you can hire. Start at septic rules by state, then confirm with your health department.
What a septic designer does
A full design usually includes:
- Site visit. Looking at the lot, the slopes, wells, water and where the house will go.
- Soil evaluation, or coordinating one with a soil evaluator. See Perc Test vs Soil Evaluation.
- Sizing the tank and drain field from the bedrooms and the soil.
- Choosing the system type your soil and county allow. See Septic System Types.
- Drawings and calculations: site plan, cross section, hydraulic profile, details. See Septic System Design Drawings.
- The permit application, and answering the reviewer's questions.
- Construction support, in some states: staking, stage checks or an as-built.
Some designers also survey; others work with a surveyor.
Where to find a septic designer
- Your health department. Many keep a list of licensed designers, evaluators and installers working in the county. It's the most reliable local source.
- Your state's licensing board. Most have a license lookup by name or county, so you can check a license is current.
- Installers. Installers work with designers every week and know who is responsive. Some design themselves.
- Builders and real estate agents. For a new home or a sale, they often know who works in the area.
- landplan.io. Browse designers by state on septic designers, and open a designer's profile to see their services and the counties they serve. Or post a job: describe the property once, and verified designers who serve your county send bids.
Questions to ask before you hire
| Ask | Why |
|---|---|
| Are you licensed for this system type in this county? | Licenses can be tiered by system complexity, and some counties keep their own lists |
| Who does the soil evaluation? | It may be separate, and priced separately |
| What's included in the price? | Site visit, soil test, survey, drawings, permit submittal, revisions, construction checks |
| How many revisions are included? | Reviewers often ask for changes |
| When can you deliver? | Soil evaluations and designs get booked up in spring |
| What system do you expect, and why? | A designer who has looked at the soil survey can give you an idea |
| Will you deal with the health department? | Many designers submit and handle questions for you |
| Do you carry insurance? | Professional liability for engineers and designers |
| Can I see a sample plan? | Shows how clear and complete their drawings are |
What a septic design costs
Design fees vary with the system type, the site and the region. A conventional system on an easy lot usually costs less to design than a mound or a pressure system, and a commercial or large system needs an engineer. Get two or three quotes, and compare what each includes, not only the number.
When you post a job on landplan.io and enough design quotes exist in your state, the job form shows the typical design quote there. For what the system itself costs to build, see Septic System Cost.
Red flags
- A price with no site visit or soil test, for a site that hasn't been tested.
- No license number, or a license that doesn't cover your county or system type.
- A promise of a specific system before the soil has been evaluated.
- Pressure to use one installer or one product without a reason.
How landplan.io works for homeowners and designers
For homeowners
Post a job. Type the property address; landplan.io shows the parcel and fills in the county and parcel number. Add the bedrooms, what the job is for (new construction or replacement), any documents (house plans, a survey, soil tests), and optionally a designer you've chosen. Verified designers who serve your county send bids with a price and a delivery date. You pick one, pay through landplan.io, and the payment is held until the design is delivered and you approve it. Messages and files stay with the job.
landplan.io doesn't do site and soil evaluations or surveys itself; your designer can arrange them.
For designers
Designers apply to be verified: company, licence (type, state, number, expiry and a photo or PDF), services and the counties they serve. The landplan.io team checks the licence and company before any jobs are shown. See Septic Design Jobs.
Docs: Jobs and Availability.
Frequently asked questions
Do I need an engineer to design my septic system?
In some states, yes, for every system; in most, only for large, commercial or complex systems, while a licensed designer can do a home system. Check your state's rules.
Can my installer design the system?
In some states licensed installers may design conventional systems; in others the design must come from a licensed designer or engineer. Your health department can tell you.
How long does a septic design take?
It depends on the designer's schedule, the season and whether the soil evaluation is done. Ask for a delivery date before you hire.
What should I have ready for the designer?
The address and parcel number, the house plans or the bedroom count, any survey, and any old permits or soil tests for the property.
How do I check a designer's license?
Most state licensing boards or health departments have an online lookup. On landplan.io, verified designers have had their licence checked by our team.
Find a designer or design it yourself
Browse septic designers by state, or create a free account and see a design for your address in minutes, then hand it to a licensed designer to check and sign.