What is the most common way to dispose of sludge in Wisconsin?

• A. Incineration
• B. Land application
• C. Ocean dumping
• D. Composting

Answer: (B)

Land application of treated biosolids is the most common way sludge is disposed of in Wisconsin. Treated sludge, rich in organic matter and plant nutrients like nitrogen and phosphorus, is applied to agricultural or wooded lands under strict regulatory controls. This recycles nutrients, improves soil, and is generally more cost-effective for wastewater facilities than other disposal options. Regulations require pathogen reduction and metal limits, plus careful site selection, timing, and monitoring to protect soil and water quality. Other methods exist, but incineration is expensive and energy-intensive, ocean dumping isn’t feasible or allowed for Wisconsin facilities, and while composting happens, it isn’t the primary disposal route in the state.