sealPurdue News

June 13, 2002

Purdue soil scientist digging for answers to septic system failure

WEST LAFAYETTE, Ind. – Purdue University is partnering with Allen County officials to dig for answers to why septic systems are prematurely failing for numerous homeowners in northeast Indiana.

Brad Lee, Purdue Extension soil and land use specialist, will study soil characteristics in Allen County and compare the soil in areas where septic systems have failed with soils where systems function properly.

"Allen County officials are aggressively looking at this problem," Lee said. "They want to understand how the soil composition impacts septic system failure in this initial study and eventually find a soil-based solution to the problem. The study also will look for an easier method to estimate how septic effluent moves through the soil."

The research is being funded with a $15,000 grant from the Allen County commissioners and Fort Wayne-Allen County Department of Health.

Allen County, along with the other northeastern Indiana counties of Adams, Allen, Blackford, Dekalb, Delaware, Grant, Howard, Huntington, Jay, Miami, Noble, Randolph, Steuben, Wabash, Wells and Whitley, are all geographically located on recessional moraines. The moraines are glacier-formed accumulations behind the outermost edge of a glacier. They form when glaciers linger in one spot for a long time. The soils in northeast Indiana are fine textured due to glacial advances from Lake Erie thousands of years ago, Lee said.

Lee said he is unsure if the moraines are causing septic problems, but that is what he hopes to unearth in his research.

In the past, soil scientists in Allen County have tested soil characteristics using a small sample, which indicated the soil texture and structure met state requirements for installing systems, said Gary Chapple, pollution control director in the Fort Wayne-Allen County Department of Health. However, premature system failure became such a problem in the moraine areas that new recommendations for soil evaluation were put in place in June 2001.

The new recommendations for this area, from the Indiana State Department of Health, involve three separate soil testing procedures. One of the recommended tests looks deeper into the soil's properties by using a backhoe to dig a pit. Mechanical analysis is then conducted on soil samples to determine its characteristics. Another procedure is a permeability test in which several holes are drilled into the soil and the rate of water movement through the soil is estimated.

"We are excited to partner with Purdue to come up with simpler tests to see if sites are acceptable to build systems that work with these soils," Chapple said.

Purdue's Environmental Sciences and Engineering Institute also will play a key role in this Allen County project. Ron Turco, director of ESEI, said the institute will look at the microbial processes that affect how septic system fields work.

Several other related projects are happening in Allen County relating to septic systems and how they affect water quality. Two projects are focusing on stream monitoring for potential contamination of ditches and streambeds with septic effluent, said Roger Moll, Purdue Extension educator and Land Use Team member.

The Allen County Board of Health is leading one of the projects to sample water from Allen County ditches and streams to assess the level of contamination. The other project, the St. Joseph River Watershed Initiative, has monitored the tributaries of the St. Joseph River for more than six years to collect water quality data. The initiative is working on getting funding to demonstrate practices that reduce runoff into streams, he said. Moll serves on the initiative's board of directors.

"We can't change the soils we have in Allen County," Moll said. "At this point we must have the initiative to study the soil profile and reevaluate the standards for septic system installation. Homeowners are frustrated with this issue, and we hope Purdue's work will help find solutions for them."

Writer: Jennifer Doup, (765) 494-6682,

Sources: Brad Lee, (765) 496-6884,

Gary Chapple, (260) 449-7530,

Roger Moll, (260) 481-6826,

Ron Turco, (765) 494-8077,

Purdue News Service: (765) 494-2096;

* To the Purdue News and Photos Page