ON-SITE Wastewater Newsletter

Features in this issue:


What is a soil horizon?

A soil horizon is a layer of soil. Layers are often distinguished by color, textural, and parent material changes. There are seven horizons typically found in Indiana. These master horizons are designated by the letters O, A, E, B, C, R, and W. Horizons assist with soil identification. They give clues to how the soil formed, how water will flow through the soil, what chemical properties the soil might have, and how stable the soil is.

W Layers: Water. This is a layer of water, either within a soil or above the soil surface. The symbol is not used for soils that have intermittent ponding.

One of the first things you may notice about a soil is a change in color with depth. Color is one of the clues to determining a soil’s horizon. The diagram shows the pattern of master horizons in a typical soil. A soil report may have combinations of these horizons, such as a BC horizon, that would indicate a transitional zone. Horizons also have modifiers on them, such as a Bt horizon. The "t" signifies that there is an accumulation of clay in the B horizon. The texture of a soil is the proportion of sand, silt and clay. Sands have a gritty feel, silts are smooth and powdery, while clays can be considered the glue that holds the particles together.

Joe Yahner is a retired professor of Agronomy, Purdue University.


An Environmental Theme

The 1998 Annual Conference of the National Onsite Wastewater Recycling Association (NOWRA) was held Oct. 22-25, 1998, at Ft. Mitchell, Kentucky. It was informative and even exciting for this writer to interact with a new group of applied professionals, most of whom had a positive approach and an informative story to tell.

The theme was "Onsite Treatment; First Choice for Protecting the Environment". It was clear that individual or clustered onsite treatment is no longer viewed as a stopgap waiting for the next bond issue to fund municipal sewer extensions. Rather, there was an emphasis on the environmental and practical advantages of adopting decentralized treatment systems with centralized management and maintenance services, especially for new development. There was also lots of interest in encouraging policy and regulatory changes that are protective of water resources while allowing consideration of appropriate technologies that meet site needs.

Anyone with interests in onsite wastewater treatment issues should become acquainted with this group's activities, services and membership qualifications.

The 169-page Conference Proceedings from the NOWRA 7th Annual Conference are now available for $85 prepaid to non-members and $60 prepaid to members (Visa, MasterCard, and Discover cards accepted). To receive more information about NOWRA and the Conference Proceedings, visit their web site at http://www.nowra.org/.

PO Box 647
Northbrook, IL 60065-0647
800-966-2942; 847-559-9233;
FAX 847-559-9235
email: 103061.1063@compuserve.com
Web site: http://www.nowra.org

John Peverly is an Agronomy Professor and Water Quality Specialist at Purdue University.

EFFLUENT FILTERS--A Low-Cost Way to Prevent Expensive Repairs

The most prominent but basic technology discussed by speakers and displayed by exhibitors during the 1998 NOWRA Conference was the septic tank effluent filter to keep particulates out of the distribution lines. There is a critical need to upgrade and prolong the operating life of the many conventional septic tank/gravity flow drain-field systems.

The septic tank may be the single most important component used in onsite treatment and collection alternatives. Its job is to collect wastewater; segregate the settleable and floatable solids (sludge and scum); accumulate, consolidate and store solids; digest organic matter; and discharge effluent via gravity flow. Currently, more than 1.9 million people in Indiana use onsite wastewater disposal or decentralized sewerage collection and treatment that rely on septic tanks for primary treatment.

Over the past decade and a half, effluent filters used on tank outlets have demonstrated a dramatic improvement in the quality of effluent discharged from septic tanks. Effluent filters are primarily mechanical filters, so particle size management is the major objective. Not only are large solids prevented from leaving the tank, but gross quantities of solids are also kept out of the drain field. Of course, inappropriate disposal of cigarettes, nutshells, eggshells, Handy Wipes, kitty litter, coffee grounds, chemicals, household cleaners, etc., can result in a plugged filter, as will failure to pump the tank periodically. While a plugged filter indicates the need for cleaning, it also can reduce damage to the downstream absorption field.

Following is a list of considerations for residential effluent filters:

The beauty of this low-tech item is several-fold: it is a simple but effective method of preventing excessive solids carryover to the filter field; it can be retrofitted into old systems; and it promotes homeowner and/or professional maintenance before the system fails. It does not, of course, correct poor septic design or improper placement. What it can do is to help prevent premature failure in an appropriately designed and placed system.


The State Department of Health continues to progress towards revising the residential and commercial on-site sewage disposal codes.

The public hearing on the proposed rule revisions was held on December 28, 1998. A number of stakeholders and interested persons submitted both verbal and written comments on the proposed revisions. These comments will be summarized by the hearing officer and presented to the Executive Board of the State Department of Health.

Although there were a number of comments provided, it appears that the major technical issues remain the same: drainage, the new loading rate table, lack of a "grandfather clause", and the prohibition of on-site systems in fill soil.

ISDH staff continues to review each of these issues, to determine what changes, if any, it will recommend to the Executive Board prior to final adoption of the rule and technical specification.

If the projected timeline is followed, the rule will go before the Executive Board for final adoption at their meeting in March 1999. After final adoption, the Office of Attorney General will review the rule prior to submittal to the Governor's Office for his signature. Following signature by the Governor, the final rule is filed by the Secretary of State, and published in the Indiana Register. The rule takes effect 30 days after filing by the Secretary of State.

ISDH staff will make every effort to keep you posted on the status of the rule revision. If you have any questions or comments, please contact me at 317-233-7177 or by e-mail at adunn@isdh.state.in.us.

Alan M. Dunn, Supervisor, Residential Sewage Disposal, ISDH


Sources: Pipeline, Summer 1996; Vol. 7, No. 3, National Small Flows Clearinghouse (800/624-8301); Plumbing and Mechanical Magazine; Environmental Engineering and Sanitation, 4th ed., by J. Salvato; and Water and Wastewater Engineering, vol. 1, Fair, Geyer, and Okun. Reprinted with permission from Pipeline.

During late January and early February of 1999, we held three workshops around Indiana (Allen, Dearborn, and Dubois Counties). Presentations were made on:

Attendance was excellent, attracting primarily installers and local health department personnel – in spite of nearly 70 weather during the Dubois County meeting. Discussion of the new pretreatment options was lively and informative. Hopefully, the new rule will speed the availability of such technologies to deal with onsite systems in Indiana’s problem soils.

Don Jones is a Professor and Extension Engineer of the Agricultural and Biological Engineering Department at Purdue University.


To borrow a video, or for a list of videos that are available, call Carol at 765/494-1174 or email carols@purdue.edu. We also have a small supply of brochures from the National Small Flows Clearinghouse for septic system owners. If you own a septic system, these provide valuable tips for maintaining your field. If you install systems, you might want to consider including these in the educational packet you provide to your customers. Bulk orders can be placed with the National Small Flows Clearinghouse at 800/624-8301.

Homer & Maud Homeowner

"I can’t believe Maud bought that story about needing a wetland for our septic system…!"


We have found some URLs that may be of interest to you. We keep a list of these, so if you turn up some that we missed, we would appreciate your submission to onsite@ecn.purdue.edu.*
ADS/On-site Septic Systems www.ads-pipe.com/markets/septic.html
Airvac, Inc http://www.airvac.com/
EPA/Principles & Design of Onsite Systems www.epa.gov/grtlakes/seahome/onsite.html
East County Wholesale www.plumbertools.com/
Indiana State Department of Health www.state.in.us/doh
Infiltrator Systems, Inc http://www.infiltratorsystems.com/
Klargester http://www.klargester.co.uk/
Landman Properties/Engineered Septic Systems http://www.thelandman.com/htmlos/htmlos/69.5.6998807697start/landman/landmain.html 
Minnesota Pollution Control Agency www.pca.state.mn.us/water/septic.html
National Small Flows Clearinghouse www.estd.wvu.edu/nsfc
Orenco, Inc http://www.orenco.com/
Septic System Help ourworld.compuserve.com/homepages/ottaway/sds_intr.htm
Terralift Systems www.kaiser-battistone.com/terra.htm
The Septic Information Website www1.mhv.net/~dfriedman/septbook.htm
Zabel, Inc http://www.zabel.com/

*"Any mention of, or links to, commercial products does not imply endorsement by Purdue University."