… and has the answer changed over time? Once upon a time, did they just pump out their load into open ravines / water? Are there differences among different countries? I can’t imagine that they discharge into some city’s public sewage system.
Mike Rowe did a “Dirty Jobs” episode. They take it to a big concrete “apron” and release it. Stinks to high heaven. But as the sun evaporates off the water, far fewer solids are left. IIRC they bulldoze the remnants into a small pit and it doesn’t smell bad.
I saw that episode as well, but don’t remember the fertilizer part. I wonder if it was Milorginite based out of Milwaukee (they make fertilizer out of poo) which is about 90 minutes away from Madison where that episode was filmed IIRC.
No, once it’s been treated, dried, etc., it’s not. Our hay supplier is a licenced “waste disposal site” and he uses the dried stuff on his hay fields every year. He gets more growings and cuttings from his fields, plus he dosn’t have to pay huge prices for fertilizer. In fact, the city is paying him to take it----he had to get a licence from them and the state of WV to accept treated waste. The hay is perfectly safe, no nasty things growing in it, etc.
If you want info on it being used to fertilize crops humans use, google “humanure” and see what’s out there.
Yeah, I think the issue is that you shouldn’t use it for fertilizer on a crop destined for human consumption, as BaneSidhe mentions—we don’t eat hay. Cow or horse manure in gardens and fields for our crops is fine, of course. With all the produce from other countries that you find in stores, let’s hope they follow the same rules.
They used to be able to spread it on fields that were not to be used for food production for a year or two. Now they are required to use a sewage treatment plant instead. The treatment facility is a much better requirement by far.
Here in New England, septage is generally required to be transported to a wastewater treatment plant for treatment. Yes, they are charged a fee for disposal.
You need special permits to convert septage/sewage to fertilizer. The regulations for this are generally pretty strict (and have been getting stricter), because a lot goes down the drain other than human waste (e.g. household cleaners, excreted prescription drugs, etc.). For the treatment plants, which pick up commercial and industrial flows, many other contaminants can end up in there as well. Hazardous waste disposal is strictly prohibited from being disposed of in sewers, but this is sometimes difficult to enforce, and contaminants can cause problems even at low concentrations. (One focus in recent years has been mercury waste from dentist offices.) For this reason, the residual solids (referred to as sludge) are generally either disposed of in lined landfills or incinerated. If the waste is incinerated, the stacks must have scrubbers, and resultant ash is disposed of in lined landfills.
I took a tour of a sewage treatment plant as part of a college class. Along with the stuff piped in they also had a tank for what they called scavenger waste which was from cesspool pumpouts. It was fed into the waste stream, but the employees said that sometimes that waste causes a ‘upset’ in the biological system that they use to breakdown the sewage. After treatment the waste is piped IIRC 3 miles into the ocean.