Why must almost all surface waters and Ground Waters Under the Direct Influence of Surface Waters be evaluated and treated for Cryptosporidium parvum?

Almost all surface waters and ground waters under the direct influence of surface waters must be evaluated and treated for Cryptosporidium parvum due to several key factors that contribute to its potential presence and resilience in water sources.

Firstly, Cryptosporidium parvum oocysts are indeed ubiquitous in many source waters, particularly those that are impacted by upstream sewage discharges. This factor significantly increases the likelihood of contamination in water sources and emphasizes the need for careful evaluation and treatment to protect public health.

Secondly, the oocysts of Cryptosporidium parvum are resistant to common disinfection methods, particularly chlorination. This means that even if the water undergoes standard chlorination treatment, these resistant forms can survive and pose a risk to consumers. Hence, relying solely on traditional chlorination is insufficient to ensure that water is safe.

Lastly, the size of Cryptosporidium parvum oocysts presents additional challenges. They are relatively small and can evade conventional filters used in water treatment processes. This makes it challenging to remove them completely through standard filtration techniques.

These factors combined highlight the necessity for comprehensive water treatment strategies that specifically address the threat posed by Cryptosporidium parvum, leading to the conclusion that all presented reasons contribute to the rationale for