dog poop composting — yes or no? a topic revisited

We share great recipes, muse about building the best playsets for our children, and delight in objects that add a little beauty to our days. But what post from more than five years ago is still getting regular comments from readers? Dog poop composting! With that kind of interest, we decided it was high time to revisit the topic.

My dog poop composter: no longer in business

First, my update: we stopped using our DIY dog poop composter after a few months. (If you’re not the DIY type, you can purchase dog waste composters, too.) Reader comments had tipped me off to some potential hazards of the compost, and as I said in my original post, two big dogs = a lot of output. Our bin filled up fast, and it seemed the waste wasn’t really going anywhere. So we went back to bagging. I’ve done more reseplace for this post, and here’s what I’ve found out.

Dog poop composting: the negatives

Maybe it’s because the Pacific Northwest is full of environmental types and ample waterways, but it seems a lot of the negative press on dog waste composting originated here:

  • The Public Works department in nearby Snohomish County, where a four-year study was conducted on pet waste composting, flat-out calls dog poop composters a bad idea: “They may seem practical, but they do not kill hazardous pathogens that may be in the waste and can pollute water. Landfills are designed to safely handle substances such as dog waste, cat litter, and dirty diapers. Yards are not.”
  • King County (where Seattle is located) is officially okay with it, but Tom Watson from King County’s Recycling and Environmental Services was less than enthusiastic in this 2009 article for the Seattle Times.
  • The City of Eugene, Oregon is cautiously okay with burying the waste, but discourages against using the actual resulting compost. Their study found that harmful bacteria and disease is present even when dog waste has turned to compost. Compost Gardening sums it up well:

Compost specialists obtained samples and tested them for salmonella, coliform bacteria, and other nasties. “We then allowed the material to sit for another six months and tested it again, hoping time and microbial competition would bring the material into the ‘safe’ level,” wrote compost specialist Anne Donahue. “It didn’t.”

Eighteen months after the crumbly-looking compost was set aside to cure, it still contained enough microbial pathogens to contaminate a planting of leafy greens.

Dog poop composting: the positives

That’s not to say opinions out there are 100% negative:

  • The USDA Natural Resources Conservation Service and the Fairbanks Soil and Water Conservation District offered dog waste composting as a solution for sled dogs. This publication from 2005 gives a detailed how-to, along with troubleshooting tips. (Note: PDF at the link takes some time to load.)
  • How-to articles from National Geographic and the Sierra Club are also pretty good endorsements for the practice.
  • This CNN/Mother Nature News article is for composting, but not for using the resulting compost: “bury it deep” is the advice (there are also some good links to more information in the article).
  • Sharon Slack at City Farmer, where I first got my compost bin how-to, has had practical success. Because Slack lives in a part of Canada where putting dog waste in the garbage is forbidden, she has been composting it for more than 15 years and says she’s only had to empty the bin once in that time.

Pet waste composting caveats

It’s a simple fact that pet waste composting poses more potential hazards than regular food and yard composting. These are the big cautions:

Don’t compost pet waste anywhere near water sources or edibles gardening

Keep the bin away from your growing vegetables, fruits and any water sources (one source said at least 100 feet from water sources). Once the waste has broken down, you can use the compost on ornamental plants, but never on something you intend to eat. (Or as the City of Eugene recommended, bury the waste, but don’t use the resulting compost at all.)

Cat or other animal waste?

Do your reseplace on other types of waste, but make sure any cat litter is biodegradable. This Root Simple post may help.

Make sure your pet waste compost will heat up consistently to 145ºF

As Tom Watson said in the Seattle Times, pet waste composters must reach high enough temperatures to kill hazardous pathogens — the USDA report says this means the bin must reach 145ºF at least once a day for several days. The Sierra Club article recommends adding other materials to keep things hot. If you’re willing to take your compost’s temperature several times daily, the USDA report has this advice:
Temperatures in fresh compost mixtures rise quickly—up to 160º F and greater—then decline slowly until the compost temperature approaches air temperature. If you do not see this rapid rise and gradual decline of internal temperatures, the compost recipe may need to be adjusted.
That same report includes suggestions for getting your compost mix correct.

The bottom line: whether you compost doo or bag it, ALWAYS PICK IT UP

The worst thing you can to do the environment is just leave your dog waste lying where it is. Check out this dog waste infographic at Mother Nature News: dog waste left on the ground can contaminate water up to 20 miles away. Dog waste contains parasites that can sicken humans. Decomposing dog waste in the water robs fish of oxygen. And on and on.

So, dog waste composting wasn’t right for me, but what about you — what will you do with the doo?

Photo by Flickr user Nick Herber; used by Creative Commons License.

 

 

From our partners

I’ve debated this idea, but in the end I always come to the same conclusion: some things simply can’t be re-used. I did enjoy reading the pros and cons, however. Made me more comfortable with my decision.

Well, it’s always the best idea to get the most out of everything. Seems like in this case it doesn’t help too much though. Thanks for the advice.

Jennifer

Why not flush it down the toilet?

I tried flushing for awhile and it resulted in a lot of mopping and washing of towels. Not a good time, at all.

Mary S

Dave, I’m both curious and afraid to ask: why so much mopping and towels? Did the toilet overflow?

Judith A

I live in the country and have a septic tank system. Could I safely put the waste in the septic tank?

Aubrey

I like the article, but “digestion” and “composting” seem to be used interchangeably. Making compost requires heating up a mix of wastes until they turn into soil amendment (stuff people buy for their plants). Digestion is breaking down wastes into a liquid form that gets absorbed into the ground (septic system). It is not worthwhile for me to compost dog waste, but I’ve almost finished installing the digester!

Mary S

Aubrey, that’s a fair point (though I imagine using the phrase “dog waste digestion” might be a little stomach-turning). Just be sure you read through the reseplace cited above — even breaking down the waste can leave behind a lot of hazards that can then wash into waterways. Thanks for reading!

Matt M

Well I was really interested din trying this after reading the first article but the follow up has made me rethink. Unfortunately (from a dog poo point of view) my garden has a river running along two sides of it and I don’t think the trout would thank me for this. It’s a real shame as I hate having to bag and sometimes double bag the poop but needs must I guess. Thanks for the information though. Keep up the good work!

Erin

Our experience mimicked yours. Great idea, in theory, but problematic in practice.