Edition 6, 1998
Features in this issue:
The University of Minnesota Extension Service is hosting a satellite conference on constructed wetlands, aerobic tanks, sand and peat filters, and spray and drip irrigation. They also will be discussing funding and management options such as homeowners associations, water quality cooperatives, and sanitary sewer districts. The conference is for interested citizens, agency staff, developers, contractors, extension educators, county commissioners, health department personnel, city council members, planning commissions, Realtors, and bankers. The conference will be broadcast at the following county extension offices unless otherwise indicated:
Several Indiana county health departments currently require on-site contractor and engineer certification. The certification usually requires that the contractors take an exam and pay a fee. Representatives from Indiana Land Improvement Contractors Association (LICA), Indiana Environmental Health Association (IEHA), several sanitarians, and Purdue University have formed a committee to discuss statewide certification. Ideas that have been generated include:
Have you considered alternative sewers? Alternative sewers may be a viable option if the population in an unsewered area is 50-100 homes or less per mile of sewer line, or homes are located in areas with hilly terrain, shallow bedrock or a high water table and conventional or other innovative systems are not feasible. They also may be used when existing conventional sewers are deteriorating and/or leaking and are too expensive to repair.
Alternative sewers are small diameter plastic sewers that are usually pressurized. They work because the larger solids are removed by an on-site septic tank or broken up with a grinder pump prior to entering the sewer line. They are less expensive than conventional sewers, require less excavation (excavation costs can be two-thirds the cost of a wastewater project), and are easier to install. They do not have to flow downhill since they are not necessarily dependent on gravity and pipes can be routed around houses, ponds, and other areas. Since sewer lines are smaller they are usually easier to seal than large diameter gravity lines, so is less likely that wastewater will seep out or groundwater will infiltrate. They also may allow more flexibility with development; sewer need not be purchased or installed until houses are built.
There are four major types of alternative sewers: STEP systems (septic tank effluent pump), grinder pump systems, small diameter gravity sewers, and vacuum sewers. Each has its own advantages and disadvantages for specific sites. Considerations for your community includes insuring watertight components, operation and maintenance requirements, electricity needs, and the possible disruption of service due to mechanical breakdown and power outages.
More information can be obtained from National Small Flows Clearinghouse (NSFC) and our web site.
Adapted from NSFC Pipeline, Alternative Sewers
Purdue University is working with ISDH to explore the possibility of starting an on-site demonstration and training center with three goals in mind; 1) to provide a training center for on-site professionals in all areas emphasizing the importance of onsite wastewater disposal. 2) to develop working demonstrations of conventional and alternative on-site technologies appropriate for Indiana. 3) to train and educate homeowners, bankers, Realtors, and others about the construction, care, and maintenance of on-site wastewater systems. The center is currently in the very preliminary planning stages. We are trying to determine both feasibility and need. If this sounds like a good idea and/or you have any suggestions or comments, let us know.
The zoning, on-site system, planning, urban sprawl dilemma is being debated around the state. On-site regulations probably shouldn’t be used to control and regulate development, but in many counties the rule is doing exactly that. Individual on-site systems take quite a bit of land, and often times a conventional sewer is too expensive, so what shall we do? Increase the lot size requirement for safety or decrease it to preserve farmland and open space? Driving around Indiana and after miles and miles of what seems like endless farmland, it is hard to see how a lack of farmland could possibly be a problem. Looking at the big picture though, it is a problem, a huge problem. Many counties have the same planning strategies that they had in the 1950’s. Indiana’s population has grown from 3.9 million to around 5.8 million since then. This has resulted in a loss of approximately 5 million acres of farmland, or about 25% loss. When will it end? We will need to deal with this issue at a state level at some point.
There are alternatives to this gradual, but continual loss of our best farmland. One alternative is cluster development. This would not only help our growth problems, it would greatly relieve wastewater disposal problems as well. Figure 1 is a diagram that shows how a piece of farmland sold for development would be developed with conventional development. Figure 2 shows how it could be developed with conservation design. As you can see, the site in figure 2 has the same number of lots (or it could have 5-10% more). However, in figure 2 the homeowner looks out at either a meadow, farmland or woods on two sides, creating the feeling of being in the country. The open space would belong to a homeowners association and used as either green space or farmland. The advantage to this type of development is that the houses are close together. It would be efficient to install a community alternative sewer system, on-site system, and well on land best suited to the utilities. Residents would pay a sewer bill to either a homeowners association or a sewer district that would provide for maintenance.
For more information on cluster development and community systems, contact Joe Yahner (765) 494-8049 or your local extension educator. A good reference is Conservation Design for Subdivisions: A Practical Guide to Creating Open Space Networks by Randall Arendt, Island Press, Washington D.C. Check it out. J
The general consensus around the state is that homeowners are not maintaining their wastewater systems adequately. So, what can be done? A first step would be for maintenance professionals (pumpers and cleaners) to start developing long term contracts with their clients. Instead of working on an "emergency" basis only, why not schedule regular service calls just as many do for furnaces? A cleaning and inspection every three to five years might be recommended (or required by the county health office) and scheduled depending on the size and type of system, and the number of residents in the home. The inspection could include locating and mapping the system, checking pumps, aligning the distribution box, directing the flow to an alternate absorption field, and making recommendations, such as making sure gutters, water softeners, and iron removal systems are not hooked into the system. Also, consider retrofitting an effluent filter to the septic tank. There are a variety available from different manufacturers, and they can save an absorption field. One-third of Indiana uses on-site systems, so there should be plenty of customers.
The University of Wisconsin has developed step by step design manuals for intermittent and recirculating sand filters. They can be obtained from SSWMP, University of Wisconsin-Madison, 1525 Observatory Drive, Madison, WI 53706, (608)-265-6595. Single Pass Sand Filters for On-Site Treatment of Domestic Wastes is publication number 16.7 and Recirculating Sand Filters for On-Site Treatment of Domestic Wastes is publication number 16.3. They cost $2.50 each.
A constructed wetlands design manual for residences is available from the National Small Flows Clearinghouse (800-624-8301). General Design, Construction, and Operation Guidelines: Constructed Wetlands Wastewater Treatment Systems for Small Users including Individual Residences (1993) discusses the basics of design, goes over four different design examples, and contains tables to minimize the math required. The cost of publication WWBLDM65 is $5.00. A more in depth analysis (engineering textbook) can be found in Natural Systems for Waste Management and Treatment by S.C. Reed, R.W. Crites, and E.J. Middlebrooks (1995, McGraw Hill, Inc.)
Remember that these systems are still experimental in Indiana. These unofficial guides outline one way to construct alternative systems and should be treated as educational material only. Adaptations for use in Indiana may be necessary. Non-rule constructed wetland policy documents can be obtained from Alan Dunn, ISDH, (317) 233-7177 and Jay Hanko, IDEM, (317) 233-0470.
Purdue has an educational computer program demonstrating the principles of on-site systems, site evaluation, construction planning, the basics of soils, and water conservation ideas. It would be useful in offices to show homeowners the basic principles of on-site systems. The program was completed in 1988, runs on MS DOS, and requires minimal hardware. It is free to Indiana county extension offices and health departments (contact Catherine Taylor at (765) 496-3454.) Others can obtain it from Farm Building Plan Service (1146 Agricultural and Biological Engineering, Purdue University, W. Lafayette, IN 47907, (765) 494-1174) for $15. Give it a look, its cool!
How many soil cores does it take to evaluate a site? This is a much-debated question because it is a matter of describing soil variability (or modeling randomness). With 428 soil series to choose from in this Hoosier state of ours, soil scientists could locate continuous acres of the same series on one side of a street, and many series in a small front yard on the other side of the street. When soil scientists were asked what they would do if time and money were not a factor, most recommended at least three cores, and stated that backhoe pits would be ideal and useful. Of course, time and money are a factor. However, it is not an excuse for one soil boring. Think about two as a minimum, with three being recommended. Hopefully the new soil evaluation process will speed things up allowing multiple cores to be evaluated more efficiently.