On-Site Wastewater Systems

In 1993, the Boone County Commission adopted an ordinance for the construction of new on-site sewage treatment facilites and for remodeling or repairs of older systems to ensure wastewater disposal in Boone County meets modern, public health standards.

For several years, onsite wastewater regulations were enforced by City of Columbia/Boone County Public Health and Human Services. Effective June 28, 2022, this responsibility has been transferred to Boone County Resource Management.

What do I need to do?

Are you:

  • Constructing a new building and planning to install an on-site sewage system?
  • Renovating an existing on-site sewage system?

If so, you must apply for a permit. Note: If you are also applying for a building permit for a new home you do not need to complete a separate wastewater permit application.

Septic tank disposal systems, lagoon disposal systems and alternative design systems must follow published design criteria shown below. These standards are uniform within the State of Missouri and are not unique to Boone County.

Although these design criteria do not guarantee the satisfactory performance of a system, they take into account the latest technology and give a higher degree of success for the proper operation of sewage disposal systems. By using this higher degree of technology for constructing/repairing/remodeling on-site sewage disposal systems, it is the hope that public health and the environment will be protected, real estate home sales will be without the present problems, and persons building new homes will receive a greater satisfaction with on-site sewage disposal systems free from past problems.

If you are constructing an addition or remodeling to add bedrooms or bathrooms, an existing evaluation of your current on-site system must be performed. You will need to provide documentation regarding your current system. This may include a soils evaluation or a copy of your on-site wastewater permit from when it was initially installed showing that the system was inspected and approved. The existing evaluation fee is $35.00.

Applying for a permit

Directions to apply for an on-site wastewater treatment system permit in Boone County, Missouri.

  • For new on-site wastewater systems, or to upgrade your existing system, fill out an application, be sure to include a copy of your soils morphology report. You may also apply in person at our office.
  • The permit fee for new construction or for upgrading an existing system is $480.00.
  • A list of certified installers and certified persons to conduct soil evaluations will be provided upon request by Boone County Resource Management. This list is also on our website, a link is provided below. You must choose an installer from the certified list to work on permitted systems. If you wish to employ an installer not on the certified list, ask them to contact the Missouri Department of Health and Human Services (573) 751-6095 for information on certification prior to doing the work. Installers must also request to be added to the Boone County Resource Management list of installers.
  • Contact a soil scientist from the certified list to have a soil evaluation conducted. A list of certified soil scientists is linked below. The wastewater treatment system is then specified in accordance with the soils evaluation and with the Boone County Wastewater Treatment Ordinance.
  • The permit application and other required documentation will be reviewed; once approved the permit will be issued.
  • An on-site inspection will be conducted to determine site applicability prior to construction or reconstruction of a system. Contact Resource Management to schedule your pre-site inspection. 24-hour notice is required.
  • A certified installer must install the septic system or lagoon in accordance with the ordinance. No backfilling is allowed until final inspection is conducted.
  • Boone County Resource Management, nor the Board of Review, guarantees that permitted systems will function as designed and are not liable for damages.

Site Inspection Requirements

Ensure the proposed system will meet the required setbacks. See the Septic System Setback Diagram and Lagoon System Setback Diagram

1. Prior to an on-site inspection, the following items must be located and marked:

  1. Property lines.
  2. Proposed location of the on-site system.
  3. Any floodplain or floodway located on the property (if applicable)
  4. Stream buffer locations (if applicable)
  5. Sinkholes (if applicable)

2. Contact Resource Management for an on-site wastewater pre-site inspection. 24-hour notice is required.

NOTE: Footing inspections will not be scheduled until a pre-site inspection on the proposed wastewater system has been completed and approved. Wastewater pre-site and footing inspections will not be scheduled for the same day.


Please see Lagoon Requirements handout.

What is a lagoon?
  • A lagoon is a small pond that receives wastewater from a home for treatment. The lagoon is three to five feet in depth and the size is determined by the number of bedrooms in a home. A lagoon works to treat domestic sewage by a biological process.

How does a lagoon work?

  • The sewage from the home enters the lagoon on the bottom. The solids stay on the bottom and become sludge. Algae, a microscopic plant that lives in the lagoon, works with carbon dioxide and sunlight to produce oxygen. Other microorganisms use this oxygen to digest the sewage. This is why sunlight and good wind action are essential for a lagoon to work properly. Trees must be cleared around a lagoon for this reason. The lagoon should also be mowed frequently to make sure the lagoon gets plenty of sun and wind.

What should be done to maintain a lagoon?

  • A properly built and maintained lagoon should have little to no odor. The lagoon may "turn over" in the spring and in the fall and have some odor for a few days. If the lagoon has an odor at other times there may be another problem. If a lot of leaves fall into the lagoon, they can cause the lagoon to smell. When the leaves begin to decompose they produce tannic acid which lowers the pH of the lagoon. This kills the algae and upsets the biological process that is treating the sewage. If this occurs, trim or cut the trees that are causing the leaves to fall into the lagoon. The water in the lagoon can be treated with two pounds of ammonium or sodium nitrate per day until the odor dissipates. Odors can also be caused when something is put down the sewer that upsets the natural process in the lagoon such as a large amount of chemicals or lack of sunlight as in extended cloudy weather.
  • If the home has a garbage disposal, it is best to have a properly sized and constructed septic tank preceding the lagoon. The tank should have at least 1000 gallons of capacity. This will reduce the fats and solids that will overload the lagoon.
  • The lagoon should be filled with water prior to operation. No additives will be necessary to start the biological process. The bacteria from the sewage will be sufficient for this.
  • The lagoon banks and area around the lagoon will need to be kept mowed and free of trees. The banks should be mowed to the water's edge. This will prevent tall grass from drooping into the lagoon where it provides mosquito breeding areas and could contribute to premature filling. Mowing debris should not enter the lagoon.
  • Remove trees within 50-feet of the lagoon to keep leaf debris from entering, avoid shading the surface and help control tree roots. Remove any other vegetation or trees which shade the lagoon, especially during the winter months. Watch for damage to the banks, especially from burrowing animals. Repair any damage immediately and reseed with grass as needed. Remove cattails and other vegetation including duckweed and floating algae masses from the lagoon immediately to minimize mosquito breeding and excess organic loading and to improve oxygen transfer. To help reduce damage to the banks, keep the fence in good repair so animals cannot get on the banks.

Septic Tanks

Please see Septic Tank Requirements handout

There are many types of onsite sewage disposal systems in use today. One of the most common is a septic tank, followed by a lateral drain field. Septic systems can be installed only if the soil is permeable. A soil scientist can evaluate the soil and determine a permeability rate. The soil will give the sewage effluent final treatment and disposal.

A standard septic system consists of a septic tank, a distribution device (either a flow splitter or a distribution box), and the drain field. Septic tanks can be made of concrete, plastic or fiberglass. They must be of watertight construction. Septic tanks must have a riser that extends to the surface, allowing the tank to be pumped periodically. Effluent filters are recommended to be placed in the outlet sanitary tee of the septic tank. Effluent filters are very effective in stopping solids from leaving the tank and clogging the drain field. A distribution device is not needed if the lateral field is installed level. If it is not level, a flow splitter may be necessary to distribute the effluent equally to all laterals. The drain field can consist of gravel with perforated 4-inch PVC pipe. Recommended alternatives are pipe or chambers.

Regular maintenance of a sewage system in the best prevention of failure. Periodic maintenance can significantly lengthen the life span of a system, water conservation and waste disposal habits are also important.

The following guidelines should be followed:

  • Practice water conservation. Water usage should be monitored to prevent flooding the system. (ie: stagger loads of laundry throughout the week instead of doing all of the laundry on Saturday). Water saving fixtures in the shower and toilets can also greatly cut down the amount of water used. Any water leaks must be promptly repaired.
  • Do not use your sewage system as a trash can by adding materials other than domestic sewage. Keep chemicals (paint, thinner, pesticides, etc) and non-degradable items such as disposable diapers, sanitary napkins, and cigarette butts, etc, out of the septic system.
  • Restrict the use of a garbage disposal. If a garbage disposal is used, the extra solids introduced into the tank can increase the accumulation of sludge by more than 50%, requiring more frequent pumping.
  • Do not pour grease or oils down the sink drain. They can clog up your drain field.
  • Have the solids pumped out of your septic tank periodically. This will need to be done every 3-5 years depending on the size of the family living in the home. Keep a record of pumping, maintenance and other inspections and keep a sketch of the system for future reference.
  • Clean the septic tank filter (if applicable) by hosing the filter off back into the tank annually, or as needed.
  • Don't cover the absorption field with a hard surface, such as concrete or asphalt. Grass is the best cover for the field. Grass will not only prevent erosion, but will help remove excess water.
  • Keep surface waters away from the tank and drain field, this includes downspouts from your home's roof gutters. Also, keep foundation drain and sump pump discharge out of the system.
  • Do not drive automobiles or heavy equipment on the system.
  • Do not disturb the area near the sewage system or the set aside repair area.

Alternative Systems

Please see the Alternative Systems handout

Alternative systems are required to be designed by an engineer and are generally used for sites that have poor soil or limiting conditions where a standard system cannot be installed, or where standard systems are not the most suitable treatment. Please see the handout for information regarding various types of alternative systems.

On-site Wastewater Treatment Systems and Soil Properties Guide

Boone County Guide to Onsite Wastewater Treatment Systems and Soil Properties

Small On-Site Wastewater System Regulations

Boone County Chapter 4 - Small On-Site Wastewater Systems

Certified Installers and Licensed Inspectors

Certified Installers - Conventional

Certified Installers - Alternative

Approved On-site Wastewater Engineer List

Approved On-Site Wastewater Soil Scientist List

Licensed On-site System Inspectors/Evaluators List

How to Get Added to Our Approved Lists

Instructions on how to become a Certified On-Site Wastewater Installer

Instructions on how to be added to the Approved On-site Wastewater Engineer List