Being on the Minas Basin, with the world's highest tides (yes! the earth actually tilts at high tide) we have to cope with coastal erosion. Old septic systems can be a problem because of leaching into the seawater.
Sun-Mar toilets are a great environmental choice and great too for cold-weather visits to our cottage. My ornamental shrubs enjoy a spring perk-up when we spread our clean compost in May.