What does a rural community do when they find that a high percentage of their septic systems are failing? The traditional wisdom is to hire a consulting engineering firm to plan and secure funding for a centralized wastewater collection and treatment system. People have been told forever that septic systems are temporary and that eventually they will have to have a "real" wastewater system. But centralized wastewater collection and treatment is expensive, and without big federal grants some rural communities may find that households are asked to pay, over a period of time of course, more than their home is worth to cover their share of a a community sewer and wastewater treatment plant. A recent example of this is Sisters, Oregon. This community of about 500 homes has many low - and fixed-income residents, many living in mobile and modular homes. A central wastewater collection and treatment facility has been designed at a cost of $12 million. It is being sold to the community with the enticement that they can receive half this amount in grant money. The rest of the story is that the cost per home is $25,000 to $30,000. A second engineering opinion is that this community doesn’t really need a central system. The soils are conducive to onsite wastewater treatment and with today’s technologies improved wastewater treatment could be provided by onsite systems for about 1/3 of the price of the "big pipe".

The problem is that our society has not effectively developed centralized management to ensure care of onsite and decentralized wastewater treatment facilities. No one would build a new treatment plant and walk off and leave it, expecting it to work. But we continually install onsite systems, bury them so well that we can’t even find them later; and expect them to work. Again, technology exists to maintain onsite systems to work in perpetuity, but they must have frequent visits by a trained maintenance professional who can recognize, diagnose, and take care of problems or see that they taken care of by a contractor.

Is it really better to collect sewage and convey it to one large treatment facility where a problem may cause a catastrophic water pollution event? Why is that better than dispersed systems, where any individual failure will cause relatively minor localized environmental problems? Near older cities, is it wise to correct failed septic systems by connecting to an old leaking sewer?

If you work with a community that is being told to "do something about their wastewater problem" encourage them to consider improved onsite and decentralized treatment systems. Many consulting firms may not be prepared to make a realistic cost-benefit comparison of decentralized and centralized technologies. They may not be completely familiar with the variety of technologies available nor with how to set-up necessary management programs. The needed information is available if they search. Encourage your communities to ask questions. If you need help, let us know. We can provide information on engineering firms who have designed effective decentralized treatment systems and others who have attended our wastewater training center to familiarize themselves with available technologies.

We have a new resource person in the department who has been hired to be the coordinator of the Michigan Onsite Wastewater Training and Education Center "MOWTEC" at the Tollgate facility at Novi. Patricia Miller comes to us from a water quality regulatory position in the Virginia Department of Conservation. Prior to her employment there she spent 2 ½ years working for the Virginia Department of Health as an onsite wastewater regulator. She also has 5 years experience in small scale wastewater systems at the USEPA National Small Flows Clearing House, a national center for information and technical assistance located at West Virginia University.

Patricia has a PhD from the University of Texas at Dallas in Environmental Sciences and B.S. and M.S. in Geological Sciences from Tulane and Ohio State, respectively. She is very well connected with water quality experts around the country, having worked with people from almost every state while at the Small Flows Clearing House. Prior to her work with onsite wastewater, she spent 7 years in private sector and 8 years in academia as a hydrologist / geologist.

Patricia is funded by grants to develop curriculum for the MOWTEC and will be coordinating and doing much of the training at that facility. Her first project is to develop a curriculum to train people to do effective evaluations of onsite wastewater systems that may be called for at the time of property transactions or, in the future, routinely with the frequency depending upon the type of technology at a given site. This curriculum is being developed in cooperation with the Rouge River Watershed but will be offered to others around the state as soon as it is developed.

Ted Loudon

Patricia Miller and I intend to conduct educational programs for local onsite sewage contractors this winter at several location, yet to be determined. We anticipate these will be one-day training programs coordinated through local health departments and offered so that each meeting covers at least two or three counties. We will also offer to conduct an evening session at each location on the basics of onsite wastewater treatment for local boards of health, boards of appeal, and other local decision makers.

A letter will be going out soon to local health departments offering this training and asking for volunteers who would like to coordinate a meeting for a region. If you believe that this type of training should be offered in your county, please give your local health department a heads-up and suggest that they watch and be ready to respond when they receive our letter suggesting these meetings. You might consider offering to help with meeting arrangements, etc.

Our goal will be to provide basic onsite wastewater training up-dates for contractors and as a side benefit sanitarians as well. We will introduce them to our Michigan Onsite Wastewater Training and Education Center (MOWTEC), encouraging them to consider coming there for a more detailed two-day training program. We expect to conduct 6 to 8 meetings of this type this year and more next year.

Ted Loudon

The useful life of soil absorption systems can be greatly prolonged by achieving uniform distribution of effluent throughout the soil absorption area. It was pointed out in the August issue of the "On the Wastewater Front" that uniform distribution is not achieved with conventional gravity flow of effluent from the septic tank to the soil absorption system.

One method of achieving uniformity is to use small diameter pipes perforated with small orifices, from 1/8" to 1/4" in diameter, and to pressurize this small pipe with a pump or a syphon. This article deals only with the use of pumps. Pressure distribution systems are designed to operate under low pressure of

1 to 3 psi. For individual homes, the pumps required are fractional horsepower, usually ½ horsepower or less. The pump is chosen by the designer so that it develops just enough flow to feed the desired number of orifices at the desired pressure.

When the system is operating, the entire pipe network fills with effluent before much flows out of any of the holes. As soon as the pipes are filled the system comes up to the operating pressure and all orifices flow at about the same rate for a set period of time or for a set volume of flow. Research has shown that the best treatment of the effluent in the soil is achieved when the dose volume delivered to the soil is as low as possible. Older systems were designed with the recommendation that the pump operate no more than 4 times-a-day to deliver flow to the soil absorption system. However, the goal of a pressure distribution system is to provide uniform, unsaturated flow in the soil and this is best done with many small doses rather than a few larger ones. The size of the system and the number of orifices will determine the required flow rate. Designers attempt to keep the volume of water delivered per dose to less than about 30 or 40 gallons per dose.

Dose volume can be controlled either by floats that turn the pump on when the water level in a pump chamber reaches a certain height and off at a certain height or by operating the pump on a timer so that the pump operates for a preset period of time. Timer operation is preferred because it not only controls the dose volume but it prevents frequent doses to the drain field when there is a large volume of wastewater discharged from the source over a short period of time.

The goal of pressure dosing is to create unsaturated flow in the soil absorption system. This means that the wastewater moves over the surface of soil particles or soil peds so that the effluent is continuously in contact with the soil air. Soil pores are never filled with water. This rapidly converts an anaerobic effluent from the septic tank into an aerobic condition and provides for aerobic microorganisms to treat the effluent as it moves through the soil profile.

Keeping the soil absorption system aerobic will reduce the development of a clogging mat or "biomat" on the bottom of the soil absorption system and thus prolong the life of the soil system.

The Michigan Department of Environmental Quality requires that all larger systems (greater than 2,000 gpd) be dosed and they highly recommend pressure-dosing anytime a system is dosed. Pressure dosing adds cost and enhances the need for maintenance but will greatly extend the life of an onsite wastewater treatment system.

Ted Loudon

The Michigan Guarding Standard for Agricultural Equipment has been in effect since 1977. The standard is a requirement to guard farmstead equipment covering the meshing point or nip-point of all power driven gears, belts, chains, sheaves, pulleys, sprockets and idlers. It also includes guarding most revolving shafts, including: projecting bolts, keys and revolving shaft set screws.

Power transmission safeguards are standard on most newer farm machinery and power-driven equipment. However, not all agricultural equipment, especially older machines, have built-in safeguards provided by the manufacturer. Operations with employees need to guard equipment and machines to comply with existing safety standards. Check the October, 1999 Safety News for ideas on types of guard materials, and user-built guard construction tips.

Safety Tip: The first place to look for the correct guard or shield is at the dealer. Possibly an agricultural salvage dealer can provide a used, undamaged "take-off" part that was original equipment on the tractor or farm equipment.

User-built guards may not conform well and could be a poorly designed risk to the shape and function of the machine. Still, user-built guards are sometimes necessary for a variety of reasons. It could be the only practical safeguarding solution according to the federal OSHA publication on guard construction.

Howard Doss

Agents and directors who have looked closely at last month’s "Safety News" found a few interesting twists in the safety chain situation in Michigan. Here are some comments on various statements:

Comment: Both Craig Anderson, Michigan Farm Bureau and I are not clear about the application of the safety chain or chains requirement for farm equipment or implements of husbandry. The enforcement of this law has occurred in Michigan, mostly in urban areas that still have active farms or nurseries. Is it one chain or two safety chains? No clear answer here, therefore I showed the adopted American Society of Agricultural Engineers Standard using one chain. I also stated the following about it.

It requires one or possibly two safety chains depending on the gross combined weight of the tractor and towed implement.

Comment: I had a discussion with an MSUE county agent. A typical 250 bu. gravity box with a load of soybeans (estimated 16,500 lb.) and a tractor have a combined weight well over the 10,000 lb. limit for a single safety chain. All of the answers are not in yet. It may take legislative action or a Michigan court case or two to clarify the law for a practical application using safety chains on farm equipment operation on public roads.

The reason for alerting everyone is the fact that tickets are being issued to farmers using this existing Michigan law.

Howard Doss

The Use of Satellite Remote Sensing
A guide to help you find selected key documents and data sets vital to understanding the use of satellite remote sensing to study the human dimensions of global environmental change http://www.ciesin.org/TG/RS/RS-home.html

The Satellite Imagery FAQ
This FAQ aims to combine some very brief introductory material with a guide to the numerous resources available on (and off) the Internet. http://www.geog.nottingham.ac.uk/remote/satfaq.html

Satellite Images
A source on-line to buy satellite imagery. http://terraserver.microsoft.com/

Roger Brook