Which problem is commonly faced by wastewater treatment plants?

Wastewater treatment plants frequently encounter odor control problems due to various factors associated with the treatment processes and the nature of wastewater. Odors can originate from anaerobic decomposition of organic material, the presence of certain chemicals, and the release of gases such as hydrogen sulfide and ammonia during treatment. This is particularly significant in facilities where sludge is handled, stored, or treated.

Effective odor control is essential, as unpleasant smells can lead to community complaints and can affect the plant's relationship with nearby residents. Plant operators typically implement various strategies to mitigate odors, such as using cover systems, chemical scrubbers, and biofilters, as well as maintaining optimal operational practices to minimize odor generation.

While other options might seem relevant in certain contexts, they do not represent common challenges faced by all wastewater treatment plants. For example, a shortage of water sources may not apply universally, as some plants are designed to treat wastewater rather than rely on new water sources. Excessive nutrient removal could be a concern in specific situations but is not as universally recognized as a widespread problem. Lastly, low energy usage is not commonly an issue; instead, many facilities strive to optimize energy efficiency, which indicates that energy usage tends to be a focus rather than a prevalent problem.