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Soils, Designs and Site Drainage

Soil Evaluators (Soil Scientists)

Ohio Administrative Code Rule 3701-29-07 requires that an evaluator shall have the knowledge and experience to facilitate the review of site and soil conditions, using information provided by the homeowner and these rules to identity appropriate areas for the siting of STS and Gray Water Recycling Systems (GWRS).  Soil Evaluators shall be knowledgeable of the requirements of this chapter, available technologies, and the science of pedology. 

Rules require that soil evaluations shall be completed by:

(1)   A soil scientist or soil classifier certified by the soil science society of America (SSSA) completing  the soil evaluation while acting as an independent agent of the owner or board of health;

(2)   A SSSA associated professional soil scientist that is supervised by a SSSA-certified soil scientist completing the soil evaluation while acting as an independent agent of the owner or board of health;  

(3)   A soil professional registered by a state or national organization with equivalent minimum qualifications and/or demonstration of competency for soil evaluation as approved by the director of health; 

(4)   A registered sanitarian employed by the board of health having jurisdiction where the soil evaluation is to take place completing the soil evaluation on behalf of the board of health when the employee is determined by the board of health to be capable of meeting the tasks in paragraph (C) of this rule; or 

(5)   Other persons approved under a certification program or other training program as approved by the director of health.

Soil Scientist Meeting the Criteria Established under Rule OAC 3701-29-07 to perform soil work in Ohio

Soil Scientist Society of America search tool to locate Soil Professionals per OAC 3701-29-07 (A)(1) and (A)(2).   

The Association of Ohio Pedologists is nationally recognized, and certification is through the Soil Science Society of America. Here is a list of AOP certified Soil Scientists who are currently available for soil consulting.

Soil Professionals registered in other states meeting OAC 3701-29-07 (A)(3) 

Soil Professionals demonstrating compliance with criteria established by the director of health under rule OAC 3701-29-07 (A)(5)

Site and Soil Evaluations

Suitability of the soil for on-site sewage treatment must be evaluated on a site-by-site basis. The adequacy of site and soil conditions for on-site treatment needs to be determined prior to considering an National Pollution Discharging Elimination System (NPDES) discharge. When site and soil conditions are suitable, the evaluation is used to consider soil absorption system options. The following ODH Site & Soil Evaluation Form is required to for use to record the results of a soil evaluation. Instructions are provided to assist with the use of the soil evaluation form. The form may be requested in MS Excel format. 

ODH Site & Soil Evaluation Form

ODH Site & Soil Evaluation Instructions

Natural Resources Conservation Service-- Field book For Describing and Sampling Soils 


Local Health Districts have provided contact information for people they area aware of that offer the service of designing sewage treatment systems.  ODH has organized the list by area code: Designers by Area Code 

Site Drainage

The Ohio Administrative Code Rule 3701-29-16 and Appendix A to this rule provide the requirements and specifications for site drainage.  Site Drainage includes the use of interceptor drains, perimeter drains and engineered drainage to manage subsurface water in areas where sewage treatment systems are installed.

Site drainage definitions are as follows and found in OAC 3701-29-01 

Interceptor Drain (HHH): means a drain designed to intercept the horizontal flow of subsurface water to reduce its impact on a down gradient soil absorption system.

Perimeter Drain (WWW): means a subsurface drain installed around a soul absorption component that is designed to enhance drainage of the area.  A perimeter drain does not uniformly lower the seasonal water table beneath a soil absorption area to increase the vertical separation distance.

Engineered Drainage System (II): means a drainage system designed to meet the specifications of paragraph (F) of rule 3701-29-16 of the Administrative Code.

The Ohio Department of Health contacted with the Ohio State University, Department of Food, Agricultural and Biological Engineering  to conduct an analysis of the engineered drainage for a subset of commonly found Ohio soils.  This modeling work builds on the original modeling conducted in 2008. 

2015 OSU Engineered Drainage using DRAINMOD 

2015 Final Report        Summary of all Soils                               

This report contains the results of modeling studies that evaluated the performance of subsurface drains to remove excess soil water from the soil profile with application to sewage treatment systems.  Sixty six representative soils series were analyzed using agricultural water management computer model DRAINMOD N II.  For each soil series, DRAINMOD was used to simulate daily water table depths under different combinations of drain depths and spacing for a period of 30+ years.  For each soil, two spacings (15 ft. and 22 ft.) and 6 drain depths ( 1 ft., 1.5 ft., 2 ft., 2.5 ft., 3 ft., and maximum profile depth) were simulated using hydrologic simulation model DRAINMOD N II.  A "No Drainage" scenario was also simulated for each soil.  The daily water table depths simulated under each scenario were analyzed to count the number of days  (NODs) in a year that the water table depths were less than or equal to 30, 45, 60, 75 and 90 cm (1, 1.5, 2, 2.5, and 3 ft.) respectively.  The outputs were then summarized to obtain probabilities of exceedance and recurrence intervals for the water table depths to be within certain depths from the soil surface.  The data were further summarized into annual summaries for each water table criterion. 

Demonstration videos are available at: Video on how to use DRAINMOD for detailed description of available results and utilities.  All of the result files including the report are available for download at: Extra Files to use with Drainmod.