About the nitrate problem, they should collect all the waste into some fermentation tank to get all that methane out from your friendly neighborhood bugs (bacteria) and use it to power a generator to supply electricity to the whole farm. Excess gas can be stored in tanks. Whatever waste that is left behind from the fermentation can held up in some tanks exposed to sunlight to grow algae. The algae can then be harvested and dried then packaged into chicken/duck/turkey feed. The circle is now complete!