DISTRIBUTION SYSTEM DISINFECTANT RESIDUAL DATA

MONTHLY REPORT TO DHH/OPH

Revised 2/5/2014

MONTHSYSTEM NAME

YEAR20 PWSID#

Date / A. No. Sites
Disinfectant
≥ 0.5 / B. No. Sites
Disinfectant
< 0.5 / Date / A. No. Sites
Disinfectant
≥ 0.5 / B. No. Sites
Disinfectant
< 0.5
1 / 17
2 / 18
3 / 19
4 / 20
5 / 21
6 / 22
7 / 23
8 / 24
9 / 25
10 / 26
11 / 27
12 / 28
13 / 29
14 / 30
15 / 31
16

Total Number of Sites Sampled:

Total in column A: Total in column B:

A public water system (PWS) is required to take its own distribution system residual samples.

Free or Total Chlorine Residuals are required to be measured as followed:

  • at the same points in the distribution system and at the same times that samples for total coliforms are required to be collected by the PWS. This includes all Routine and Repeat Total Coliform samples;
  • at an additional number of sites equal to 25% times the minimum number of total coliform sites required per month (known as additional chlorine residual [ACR] site(s)); and
  • at the site that represents the maximum residence time (MRT) where the water has been in the system the longest relative to the entry point to the distribution system at least once per day.

OPH “recommends” that residuals be taken weekly at each coliform sampling site.

Disinfectant residuals must be maintained at a minimum of 0.5 mg/l (either free or total chlorine residual depending on disinfectant used) throughout the distribution system. Increase monitoring to at least daily for any site that measures less than 0.5 mg/l (free or total).

NOTE: Heterotrophic Plate Count (HPC) is not available in Louisiana as of June 93.

Prepared by (Print / Sign): ______/______Date: ______

Operator Identification #: Water Treatment Certification Level: ______