Last month we asked ... what can you do with a leach field?
Another thing not to do with a leach field is compact it. Do not use it for a parking lot or drive way. I have my doubts about pasturing goats, cattle or horses on leach fields although it might not be too serious a problem if the soil structure is good (ours isn't) and the animals aren't crowded. I see no problem with pasturing a reasonable number of chickens. Growing trees near leach lines is generally discouraged because of their aggressive root systems.
Back to the question at hand; consider planting animal food crops or flowers that do not require irrigation. If you think nothing can grow in your area without irrigation, think about locally native wild flowers--they obviously can survive on rainfall alone. If you live in a dry area, check out the Seed listing of Native Seeds/ SEARCH (520-622-5561, www.nativeseeds.org) and look for the words, "dry farmed" in descriptions. Native Seeds/SEARCH collects, conserves, documents and distributes arid-adapted agricultural seeds. They list plants (tomatoes and onions for example) that I wouldn't put on top of a leach field, but they also list crops like wheat and sorghum which can easily be hand harvested for animal feed. Wheat and sorghum both have relatively shallow root systems and need relatively little water. Chickens can harvest their own wheat but must be kept away from a seedbed until it is established.
I have built shallow berms on top of our relatively new leach lines to prevent seasonal rain runoff from collecting over the leach lines (which it did immediately after construction). During last summer's rains, I scattered hollyhock seeds as well as local native wild flowers on the berms. A few of these seeds seem to have gotten established and I'll scatter more seeds next summer. Between leach lines, I've planted dry land alfalfa and canola (listed as cover crops by Peaceful Valley, 888-784-1722, www.groworganic.com). I give them a bit of graywater in long dry spells. I plan to move my chicken tractor over those and other "cover crops" and let the chickens do the harvesting. I've noticed chickens especially like strong flavored greens like canola, mustard and turnip tops.--Edna Weigel,, Bisbee, Arizona
I wanted to respond to the question, "What on earth does one do with a leach field?"
Leave it alone! The leach field is designed to discharge waste from a septic system. If you start digging and driving poles you damage the drain line. In the state of Texas leach fields are being replaced with aerobic systems. Leach fields cannot discharge anything above the ground, so if you walk the line and find soft or wet spots you have a problem--and that can be expensive! Septic systems must be a minimum of 50 feet from any water well, and cannot drain toward creeks or rivers. The new aerobic systems must be installed with purple PVC to identify that it is wastewater. If the leach field you have is right down the middle of the 20 acres then see if it can be moved to drain in another direction, but it won't be cheap. If it can't be diverted, leave it alone.--Ralph Oliver, Home Inspector, Sealy, Texas
I have seen a number of leach fields in my younger days--if a guy of 54 can say that--and each was normally attached to a septic tank in an out-of-town environment. Everyone I know didn't do all that much with the discharged water, and it became obvious where the pipes were since the grass grew faster over them. The area over the drainpipes seemed to always have the greener grass, even when it hadn't rained for a month. In botany class I learned the roots of plants tend to filter out the vast majority of the solid materials available, taking in mostly water, minerals, and other soluble nutrients. Hardwood trees and some plants can absorb metals if dissolved enough in the soil, so one might want to be careful with using hardwoods for firewood or sawdust for the garden plants. In most cases the amount of dissolved metals like lead or aluminum is very, very small, but over time, in an old house fireplace, there would be an opportunity for the smoke to deposit the tiny amount of metals over time, in my opinion. Even so, I have not read more than two articles in the past that said an old fireplace could build up enough metals in hardwood or softwoods to become a concern for the next generation. Therefore, if a person wanted to grow firewood near a leach field, I see no real issues with the idea, except for the tree roots getting into the pipes and hindering the flow of water or solids through the system.
Needless to say, I haven't read any reports about plants absorbing harmful bacteria or other like concerns, but I am sure someone will say they have, even if the field never had standing waste water after too much rain, and too many visitors staying too long. I have seen on tv a few examples of what happens when the soil be comes saturated and the leach field begins to backup. Normally the few examples I have seen were part of a home improvement type of program, and plumbing in the country became part of the show.
Depending on the engineer's decisions, I hope to put in a septic tank with a slightly larger leach field arranged to feed the roots of some grains I plan to grow for the meat animals and fowl over the years. Needless to say, I will want to put the pipe in rows, with about three or four feet between them. I will also be using a no-till method for planting the grains, alfalfa, and dusting the plants with grass clippings and processed dried leaves from the prior fall. The idea is if a person keeps an inch or more of mulch on the soil, the moisture won't evaporate as fast and the plant roots can benefit. I have used this method of organic mulching in past gardens, and even in a large spot for mulching clippings and leaves from a guy in the lawn care business. The area always kept moist, even after two months of no rain and very dry clay soil all around it. Of course the pygmy goats have done all they could to help me "process" the dry leaves and fresh cut grass. Since I didn't have anything growing in the spot the lawn care guy put his clippings, I didn't try to keep them out and thought of their help as a great benefit. The goats got fed, stayed fatter, and I got great compost the next spring for garden plants, trees, or bushes.
As far as I know, a good leach field could grow a lot of feed for them and I wouldn't need to do any extra watering.
At the moment the mobile home is on site, but I haven't heard if I can get a meter on the 4" rural water pipe that runs past the front of the five acres. --Tsavah
We do have some concerns about your "free" grass clippings. It would be a good idea to make sure they aren't coming from lawns which have been sprayed with pesticides or other chemicals-especially if the goats are eating the contaminated clippings and you're using the milk or meat from the goats.