LT2
By providing the highest quality data on the market, our clients and regulatory agencies have the confidence that the data generated by UL meets all the compliance requirements of the Environmental Protection Agency's Long Term 2 Enhanced Surface Water Treatment Rule (LT2). As proof of this commitment:
- UL was one of the first laboratories to be granted EPA Approval Pending status for analyzing for Cryptosporidium using Method 1623 (full approval was granted upon rule finalization)
- UL has consistently outperformed other laboratories participating in the EPA's performance testing (PT) studies using Envirochek® HV filters

In addition, our customer service team members are fully trained in the requirements of LT2 and are ready to assist you with determining your system's monitoring schedule.
About the LT2 rule
LT2 is designed to reduce disease incidence associated with Cryptosporidium and other microbial pathogens in drinking water. All public water systems (PWSs) using surface water or ground water under the direct influence of surface water will be required to monitor their source water for Cryptosporidium and/or E. coli and turbidity under the LT2 rule.
Systems serving more than 10,000 people will be required to monitor for Cryptosporidium and E. coli for two years. Systems serving less than 10,000 people initially monitor for E. coli for one year, then monitor for Cryptosporidium only if they exceed their E. coli trigger values.
Let us assist you with the key elements of complying with LT2, including:
- Scheduling your sample collection - PWSs must submit a sampling schedule to the EPA no later than three months prior to beginning monitoring. The rule provides a two-day window on either side of your scheduled collection date to collect your sample. We encourage you to begin reserving your preferred collection dates now with our laboratory.
- DCTS Reporting - All results generated by our laboratory are automatically uploaded to the EPA's LT2/Stage 2 Data Collection & Tracking System (DCTS) as required by the rule. Once the results have been posted, they are available for your system to approve.
Additional resources
Use the following resources for more information on the LT2 rule:


