Under the LT1-ESWTR, what contaminant is specifically addressed?

The correct answer focuses on Cryptosporidium because the Long Term 1 Enhanced Surface Water Treatment Rule (LT1-ESWTR) was specifically developed to address risks posed by surface water contaminants, particularly pathogens like Cryptosporidium. This microorganism is resistant to conventional water treatment processes and can cause gastrointestinal illness. The rule aims to ensure that public water systems adequately monitor and treat for this specific contaminant, thus enhancing the safety of drinking water sourced from surface water.

The LT1-ESWTR emphasizes treatment techniques and specific monitoring requirements to reduce the risk of contamination by protozoan pathogens, including Cryptosporidium. Therefore, recognizing this rule's focus helps water treatment operators improve compliance and protect public health effectively.

The other options, while they do represent concerns in water safety, are not the primary focus of the LT1-ESWTR. Nitrogen compounds, heavy metals, and organic solvents involve different regulatory frameworks and treatment challenges not specifically addressed by the LT1-ESWTR's concentrated effort on the control of pathogen risks in surface water.