Fill & Wait - Why? What? & How?

When the results of a site evaluation show that the site has poor soil with no real suitable location to install a lateral field or other type of secondary treatment it will be necessary to develop an area for system installation.

This is accomplished by utilizing what is known as a “fill & wait’. The basic principal of a fill and wait is that top soil, of group lll (three) classification or better, is imported onto the site and spread in a designated area to establish a lateral field area. It is then mandatory that the area be left undisturbed for a period of one year so that the soil can properly settle. It is important to note that the importation of the top soil along with the one year wait does not guarantee the approval of an onsite system. If the property has been altered destructively as it pertains to the wastewater system, or if the top soil in the fill area has been compacted or damaged, in some manner, denial of a permit for the system installation can occur. During the one year waiting period, no building plans will be stamped nor can any construction of any kind take place at the site.

At the time of the site evaluation the health inspector will note on the site evaluation form the amount of top soil that will be required, the depth of the top soil after placement, the size of the field, and the location that the lateral field is to be developed on. The site evaluation will also detail the proposed system to be installed after the one year wait. It is important to conform to all of these requirements.

A fill and wait must follow certain criteria for development. Initially, the top soil to be imported must be preapproved by the health department prior to placement. Before the installation can begin the proposed lateral field location must be prepared by tilling the original soil to a depth of 6 inches and removing the surface vegetation. The top soil can then be installed, however, if the installation is performed by an unskilled installer and the top soil is compacted the approval of a system installation permit will most likely be denied or the waiting period required will be increased. The fill must be extended around all sides of the designated area to a minimum of 10 feet, except on sloping sites where the fill on each end of the system shall expand outward to a minimum of 15 feet at the lowest point down slope. A fast growing ground cover such as grass must be applied to the area to prevent erosion during the waiting period.

Once the top soil has been approved for importation, the site has been prepared, the top soil properly installed per the site evaluation instructions and the ground cover has been planted, the health department must visit the site for an inspection of the work performed. Once the health department has agreed that the lateral field area has been properly established the one year waiting period will begin. It is wise to rope off the lateral field area for added protection from any damage. In addtion, hay bales should be placed around the upper edge of the lateral field to assist in preventing erosion of the field.

At the conclusion of one year, the health department must visit the site to inspect the area for the system installation permit approval. The health department inspector will check the lateral field area for proper settlement and to insure that no damage of the area has occurred during the waiting period. Once approved a permit can be obtained and the wastewater system can be installed. Building plans can then be stamped for the start of construction. After the wastewater system has been installed the final inspection by the health department is performed to insure that the system permitted has been installed properly. The health department will forward a copy of the final inspection report showing approval of the installation.

Other topics: Sewage Protection Program | Site Evalations & Building Permits | Health Department - Friends not Foes | Engineering & Design for Difficult Sites | Potential Property Owners Reference

Back to Articles | Top of Page