Why is high strength (high BOD) waste a concern for Publicly Owned Treatment Works (POTW)?

High strength waste, characterized by high Biological Oxygen Demand (BOD), poses significant challenges for Publicly Owned Treatment Works (POTWs) as it requires more intensive treatment processes. The BOD indicates the organic matter present in the waste, and a high level signals that a larger amount of oxygen will be needed to break down this organic material in the treatment process. This often translates to a higher operational cost for the POTW due to the need for additional resources, such as energy, chemicals, and possibly infrastructure enhancements to handle the increased load.

Moreover, higher BOD levels can result in inefficiencies in existing treatments, as the systems may not be designed to process such concentrated waste without modification or expansion. This not only raises treatment costs but can also lead to longer-term implications for the facility's infrastructure and maintenance needs. The complexities of treating high strength waste effectively may drive up overall treatment expenses, making it a critical concern for POTWs in terms of budgeting and resource allocation.

In the context of the other options, while increased pollution risk, legal liability, and excessive labor requirements are valid issues presented by high strength waste, the most direct and prominent concern that aligns with the context of cost management and operational challenges is indeed the cost of treatment. Understanding and