Entry point to the distribution sampling

Each entry point to the distribution sampling (EPTDS) location is a required sampling point for water quality parameters. Typically, the collection frequency of these entry point samples is every 2 weeks for systems with corrosion control treatment installed and quarterly for systems with a source change, treatment change, or an exceedance of the lead or copper action level. A water supply should refer to its annual monitoring schedule for the required number of samples to be collected, the sample collection frequency, and the water quality parameters to be analyzed.

Entry point tap samples must be representative of the water quality being supplied to the distribution system. It is recommended to run each tap for 5 to 10 minutes before collecting the samples.

Certain water quality parameter samples should be measured with a field kit, while other samples may be submitted to a laboratory for analysis. A water supply must ensure that field test instruments are calibrated and maintained according to manufacturer specifications. When submitting samples to a laboratory, a water supply should ensure that the required hold times, thermal preservation, and other requirements are met.

Entry point monitoring frequencies are not eligible for reduction.