Wells & Septic fields are crazy up here now - the system must be engineered/stamped, and can only be installed by approved contractors. A typical upscale, medium size, new house was built last year two doors down, my neighbour told me that the homeowners paid $100,000 (Cdn) for the water wells and septic field.
Where you are is unique weather wise because you get at least 6 months of dry, warm weather - gray water and black water will always be constant as long as someone is living there. Then you get at least two months of heavy rains, with no, or very little 'storm drains'. This is can create problems. The book I was mentioning "Foundations & Concrete Work", from the editors of Fine Homebuilding (Taunton), explains that today most new subdivisions in the United States do not provide storm sewer hookups. The systems are already overloaded, and technologies like pervious concrete (water runs through it, rather than along it) and the book shows how to build dry wells, french drains - but they are all referring to roof runoff water, sump pump run off water. Soil at the bottom of the trench is mixed with dry cement and tamped. Then the smooth pipe (size depends on volume needed), with cleanouts every 50 feet, then gravel, then filter fabric (landscape cloth), then the topsoil. This will transport surplus water anywhere you want to go. The Australian ebook on greywater that I have, says the problem with greywater is that it still contains fecal matter from the washing. I had a little chuckle about Australians, but then again, who really knows?
