The Pulse

What is your compost made of? Use public records to find out.

By: - April 26, 2019 9:16 am
The sludge from DAK Americas that was shipped to McGill Environmental. This sample is from the same batch that contained 20,400 parts per billion. The colored specks in the sludge are bits of plastic. DAK manufactures plastic resins, known as PET (Photo: Lisa Sorg)

Read the two-part investigation about how a lack of federal regulations and state oversight allowed 1,4-Dioxane, a likely carcinogen, to be trucked in wastewater sludge from DAK America, a plastics plant in Fayetteville, to McGill Environmental, which used the material to make compost.

Staking out a McGill Environmental truck was not how I planned to spend Christmas Eve.

Yet a few days before, I received information from a worker who was concerned about the contents of sludge that DAK Americas, LLC on Cedar Creek Road in Fayetteville was sending to McGill Environmental, a composting facility in Sampson County. A truck bearing the McGill logo would be leaving the DAK plant that day.

The tip launched a four-month investigation that posed an ethical question, although one with an easy answer. I needed to confirm a lot of information before the story could proceed. I verified the worker’s name and employment. I agreed to keep the person’s name confidential so that they wouldn’t lose their job. I confirmed when DAK was shipping its sludge to McGill.

Through McGill’s annual reports, which were provided by the NC Department of Environmental Quality, I learned DAK shipped tons of sludge to the composting company each week, and had done so for several years.

Through the EPA and state environmental websites, I learned that DAK discharges 1,4 dioxanea likely human carcinogen — into the air and the Cape Fear River. State regulators had also detected groundwater contamination at the Cedar Creek Road site. Might 1,4 dioxane be in the sludge?

I gave the tipster two sterile quart jars to obtain the material from a shipment delivered later in the winter. I took the samples immediately to Pace Labs, which is EPA-certified, to ensure it met quality control standards.

(Before arriving at the lab, I had to spoon the noxious sludge — quite possibly the worst smell I’ve ever encountered– into specially prepared lab bottles. I did in a parking lot wearing turquoise protective gloves and using my hatchback as the “lab.” To outsiders it probably looked like I was disposing of a body.)

In about 10 days, I received an email with the results. I was prepared to be underwhelmed. Instead I was astonished. The sludge tested at 20,400 parts per billion for 1,4 Dioxane, plus 3,180 ppb for acetone and 1,790 ppb for methylene chloride. None of these compounds is optimal in sludge, but 1,4-Dioxane is the biggie.

There is no enforceable Maximum Contaminant Level for 1,4-Dioxane  in drinking water, although the EPA and the state recommends that concentrations not exceed 0.35 ppb. There is no regulation of 1,4-Dioxane in sludge or in finished compost. Nor are there regulations for perfluorinated compounds (PFAS) in that material.

When finished, McGill’s compost is shipped to gardening centers, private farms, city parks departments, golf courses — all places where people could be exposed to it. 1,4-Dioxane has already contaminated groundwater, rivers, lakes and drinking water supplies throughout parts of North Carolina, so it also poses a serious environmental threat.

The results presented an ethical issue: Even though I hadn’t finished all of my research and reporting — the finished story was months away — I had to tell the companies and DEQ what the sludge contained. This was not a “gotcha” story. I felt I had a public health duty to immediately tell the companies and the state Department of Environmental Quality what I had found.

How to read a composter’s annual report

So, short of sampling potentially contaminated sludge, how do you know if a bag of compost is free of 1,4-Dioxane and PFAS? Well absent testing requirements for those compounds, you can’t be certain, but certain materials are more likely to contain them.

Call the compost company and ask for a list of its “feedstock” — industry parlance for the raw material that enters a compost facility. Some companies accept only yard waste and non-meat food scraps; in North Carolina, these are known as Type 1 facilities.

DEQ has a map of all the composters in the state, listed by name, type and size.

If the facility accepts animal manure or “wastewater residuals,” aka sludge from pharmaceutical companies, or city or industrial wastewater treatment plants, then that could merit looking for a different product. These facilities are known as Type 4 in North Carolina. To know more about what’s in the wastewater, those discharge monitoring reports, including from DAK, are public record.

You can request these records from either Sarah Young in the Division of Water Resources ([email protected]) or Laura Leonard in the Division of Waste Management ([email protected]). Some composters are permitted under DWR, and others DWM, so ask both of them.

You can also ask for the company’s latest test results of its finished product. Compost companies are required to test only for a small number of contaminants, and PFAS and 1,4-Dioxane aren’t among them, but the results are still good information to have. If the composter is in North Carolina, this information is public record.

For example, below are links to McGill’s annual reports from 2015 to 2017.




Let’s look at the 2017 report, page 7, which begins the “Residuals Summary.” This tells you who sent what to McGill and when, plus the amount. In 2017, DAK in Fayetteville sent 322 tons of sludge to McGill. The composter also accepted sludge from more than a dozen municipal wastewater treatment plants.

Pages From McGill Annual Report 2017 (Text)

Page 12 lists the “Amendment Summary.” This material is mixed with the sludge. In 2015, for example, McGill accepted fly ash. And on page 122, McGill has listed every place the compost went, by name and tonnage.

McGill Amendment Summary 2017 (Text)

Other parts of the report explain the composting process and the test results for metals and pathogens. If you have space, you can also make your own compost. The North Carolina Extension tells you how.

I also wanted to know what was in McGill compost. I requested that it be tested for 1,4-Dioxane, which again, is not required under state and federal law. The results came back as non-detect for 1,4 dioxane but still high for acetone —652 ppb. Arsenic and lead were also present, at 8.4 ppb and 13.5 ppb respectively, but well below the EPA’s maximum contaminant levels for biosolids applied on land.

However, there were potential quality control issues with the sample because I didn’t know the age of the compost. It might have exceeded the lab’s 10-day “hold time” — the allowable length of time between the collection of the material and the testing. Hold times vary by chemical and compound, depending on how quickly they begin to degrade. Exceeding the hold time can skew results.

The good news is the story compelled the NC Department of Environmental Quality to intervene. The case isn’t resolve yet, because 1,4-Dioxane isn’t regulated by the EPA or the state. But state officials did confer with DAK about managing their discharges of 1,4-Dioxane, and sampled McGill compost for contamination. Those results are due back by the end of the month. We’ll report on those findings, as well as the draft compost rules as they are potentially shaped by public comment — maybe even yours.

Our stories may be republished online or in print under Creative Commons license CC BY-NC-ND 4.0. We ask that you edit only for style or to shorten, provide proper attribution and link to our web site. Please see our republishing guidelines for use of photos and graphics.

Lisa Sorg
Lisa Sorg

Assistant Editor and Environmental Reporter Lisa Sorg helps manage newsroom operations while covering the environment, climate change, agriculture and energy.