Compost from Sewage, Is it Safe for a Vegetable Garden?
July 15, 2020
I need a lot of compost for my vegetable gardens, and I am actively composting, using grass cuttings, kitchen scraps, and sawdust. I know that I will not be able to make enough compost for my whole garden.
I found out that the cities of Artesia and Carlsbad, NM have free compost. They make it from their sewage treatment plant. Is this kind of compost safe and effective for vegetable gardens? The employee I spoke with said that their customers like it a lot.
Thank you for your help.
Answer from RR: Your question will be received by a few master composters who also may
comment. Here are my thoughts.
Great to hear that you are home composting. Compost made from sewage has to reach a temperature greater than 130 degrees F for about a week in order to kill the pathogens potentially harmful to humans which live in the sewage. My guess is that if Artesia and Carlsbadproduce this compost to distribute to the public, they probably meet this requirement. However, you never know unless the proper tests are conducted to ascertain so. That is why our organization does not advise home composters to use sewage for compost whose use is intended for vegetable gardens. We recommend using this compost on ornamentals because, as you've heard, it's really good stuff. That said, the decision on what to put in your compost or what type of compost to use for any particular purpose is yours.
Answer from JZ: Agree with all that RR has sent you. The ABCWUA has been composting biosolids for many years, the compost is sold to the public. See: Compost
Any manure is best composted with a hot process as Rod has mentioned.
Another consideration for your garden soil fertility is cover / green manure cropping. You could plant a winter crop in late August, early September, eg. winter wheat / rye. This crop will be photosynthesizing thru the season, thus eventually feeding the soil microorganisms with carbohydrates (sugar). Then in the early spring you could gently till the crop into the soil where it will decompose (compost) adding residual nutrients and organic material to your soil. This article may be helpful: https://aces.nmsu.edu/pubs/_a/A150.pdf
All the best. Compost on….