In Texas, when is disinfection of treated effluent not required?

In Texas, disinfection of treated effluent is typically not required when the detention time is 21 days or more. This is based on the understanding that longer detention times allow for natural processes, such as sedimentation and microbial activities, to reduce pathogens and improve water quality. During this extended period, the effluent can undergo significant treatment through natural die-off of harmful microorganisms, thus decreasing the need for additional disinfection measures.

Detention times shorter than 21 days may not allow sufficient natural attenuation of pathogens, which is why disinfection would still be necessary for those scenarios. Additionally, the size of the treated effluent volume and temperature do not directly relate to the requirement for disinfection in the same manner as the detention time does. In conclusion, the prolonged detention period provides adequate opportunity for the effluent to become cleaner, reducing or eliminating the necessity for further disinfection.