Sewage Sludge FAQ

Since we receive quite a lot of questions regarding sewage sludge on a regular basis, we thought it might be best to create this brief FAQ section.

Frequently Asked Questions Regarding Sewage Sludge

1. What is sewage sludge?

Sewage sludge is the solid leftover that remains after removing the liquid part from treated wastewater. Wastewater is made up of everything that goes down our drains and toilets. Sewage treatment plants are responsible for cleaning the liquid part of wastewater, so it’s safe to discharge into surface water.

2. What happens with the wastewater in a treatment plant?

First, raw sludge decomposes in a digester tank. To stabilize the sludge, a broad range of chemicals is used, which later might end up in our food or water supply. According to government authorities, nontoxic sludge can be used as a soil conditioner/fertilizer and to produce fuel.

3. Where does wastewater in treatment plants originate from?

There are two main sources for wastewater. The first source are private homes. The second source are factories that produce waste.

4. What substances does sewage sludge contain?

The American Society of Civil Engineers has proven that sewage sludge usually contains the following toxins:

  • Polychlorinated Biphenyls (PCBs) – highly toxic
  • Polybrominated Diphenyl Ethers (PBDEs) – cause disorders and thyroid malfunctions
  • Pesticides
  • Dioxins – accumulate in our bodies  and are potential carcinogens
  • Arsenic
  • Cadmium
  • Chromium
  • Lead
  • Pathogens
  • Radioactive compounds
  • Asbestos

5. Where does sewage sludge end up?

Sewage sludge ends up on farmlands across the United States. Almost 100 million tons are distributed each year.

6. Does sewage sludge pose health risks?

Yes, it does! Although little is known about the longterm consequences of sewage sludge exposure, these are some of the common symptoms that people living near farmland treated with sewage sludge have reported:

  • Extreme coughing and respiratory problems
  • Burning throats and eyes
  • Headaches
  • Fever
  • Skin rashes
  • Nausea

7. What can you do to protect yourself?

If you live near farmland treated with sewage sludge, there is not much you can go. You should make sure to have your windows closed during summer at all times and wear respiratory protection.

8. The government claims that treated sewage sludge is safe. Is that true?

The government labels treated sewage sludge as safe and calls it “biosolids”. As far as we know, there is no scientific that backs up this claim.