FSMA Produce Safety Rule

Online Calculator

Determining Your Microbial Water Quality Profile (MWQP) for Agricultural Water Used in the Production of Fresh Produce


Overview
Instructions for Microbial Water Quality Profile
Approved Testing Methods
Recommended Mitigation Steps
Water Testing Labs

Samples
Water Source Type: Surface Water

Sample Date
Sample Location/ID
Sample Stage
Colony Forming Units (CFU E. coli /100 ml)
Note

Table 1. Your Microbial Water Quality Profile (MWQP)



Table 2. Your MWQP Compared to the Produce Safety Rule (PSR)

CAUTION: Using fewer than 20 samples for GM and STV does not satisfy the requirements of the rule.

CAUTION: As specified by the FSMA PSR, samples contributing to your MWQP must be calculated over a minimum of 2 years, but not more than 4 years.

  GM STV
  E. coli
CFU/100 ml
Log E. coli
CFU/100 ml
E. coli
CFU/100 ml
Log E. coli
CFU/100 ml
PSR Criteria 126 2.100 410 2.610
Your MWQP Results

Important Notes



What would you like to do next?
     
You may print results directly or transfer them to an Excel spreadsheet. To transfer results to Excel: select all text on the Print Preview, copy the text, and paste the text from the clipboard into Excel.




Support Provided By

CPS Center for Produce Safety
Maricopa Agricultural Center
UCDavis - Western Center for Food Safety
University of Arizona - Cooperative Extension
University of California - Agriculture and Natural Resources
Univeristy of Arizona - Soil, Water and Environmental Science
Yuma Agricultural Center


For More Information, Please Email:


Channah Rock, PhD
Linda J. Harris, PhD



 
Terms of Use: FSMA Produce Safety Rule Online Calculator shall be used at the users own discretion. Advice offered within this calculator is based on FSMA agricultural water recommendations and is intended to be used as a tool to assist growers with agricultural decision making. The creators of this online calculator will hold no responsibility for decisions made based on its use. All data entered into the calculator is completely private and can only be seen by the current user. No personal information nor water quality information will be saved, collected, nor sent for use by third parties.

Disclaimer: Advice offered with the FSMA Produce Safety Rule Online Calculator is based on FSMA agricultural water recommendations. The creators of this online tool assume no responsibility for the use of advice generated by the tool, any decisions associated with that advice, or any outcome arising from such use.

Proceeding beyond this page indicates that you read and understand the terms of use of the FSMA PSR Online Calculator.

   

Note: Municipal water is drinking water quality and does not require testing to be used for irrigation. Exceptions to this rule apply if the municipal water is held or stored under the same conditions as ground water or surface water. Click here to learn more about municipal water for agricultural use.

The Federal Register Notice for FSMA includes regulations from the Produce Safety Rule. Click the links below to go directly to relevant sections of the Federal Register Notice where municipal water for agricultural use is further defined.

Section 112.45(a): Establishes that there is no requirement to test any agricultural water that is subject to the requirements of Section 112.44 when any of the following apply:
1. You receive water from a public water system, as defined under the Safe Water Drinking Act (SWDA), that meets microbial requirements and you have results/certificates that demonstrate compliance. From section 112.46(a)(1).
2. You receive water from a public water supply that furnishes water which meets the microbial quality requirement in Section 112.44(a), and you have public water system results/certificates that demonstrate compliance. From section 112.46(a)(2).
3. Or you treat water in accordance with Section 112.43. From section 112.46(a)(3).
Note: If water from a municipal (public water) system is held in a ground water or surface water capacity, then the water is exposed to potential contamination and testing requirements for ground water or surface water from sections 112.46(b) and 112.46(c) must be applied. Click here to view additional detail in the FSMA Federal Register.

Click here to download a user-friendly pdf of each agricultural water regulation and section number in table format. This document is a product of the Produce Safety Alliance.

This tool calculates your surface water Microbial Water Quality Profile (MWQP). Per the PSR, a minimum of 20 samples are required to obtain a valid MWQP.

Initial MWQP:
1. Collect at least 20 water samples that are representative of use and collected as close as is practical to harvest. These samples must be collected over a minimum period of 2 year(s), and not greater than 4 year(s).
2. Analyze water samples to quantify generic E. coli/100 ml (usually by a testing service).
3. Enter water sample collection date in the first text box below.
4. Enter water sample collection location description or ID in the second text box.
5. Select the sample stage as Initial.
6. Enter E. coli lab results (E. coli CFU/100ml) in the fourth text box. Note: If your sample result is below the limit of detection at LOD <1 (or zero) generic E. coli CFU/100 ml), enter 1.
7. Add Notes if necessary (eg. rainy day, cloudy water, low flow). Press "Add" Note: Samples will appear by date in Table 1.
8. Repeat step 3 to 7 until you have entered 20 samples.
9. Review each table to determine your Geometric Mean (GM), Statistical Threshold Value (STV), and compliance with Produce Safety Rule (PSR) requirements:
a. Table 1: Displays Your Microbial Water Quality Profile (MWQP) in the bottom two rows. The GM and STV are your MWQP.
b. Table 2: Displays Your MWQP Results Compared to the PSR microbial water quality criteria.
c. Table 3: Determines if your MWQP meets PSR criteria and if microbial die-off is required. Table 3 will only appear after one or more samples have been added.

Annual Survey
Following establishment of your initial MWQP, update your MWQP annually as follows:
1. Collect at least 5 water sample(s) that are representative of use and collected as close as is practical to harvest.
2. Analyze water samples to quantify generic E. coli/100 ml (usually by a testing service).
3. Enter 5 current year sample values as described above in Step 3 to Step 7. For Sample Stage, choose Annual instead of Initial.
4. Review each table to determine your Geometric Mean (GM), Statistical Threshold Value (STV), and compliance with Produce Safety Rule (PSR) requirements:
a. Table 1: Displays Your Microbial Water Quality Profile (MWQP) in the bottom two rows. The GM and STV are your MWQP.
b. Table 2: Displays Your MWQP Results Compared to the PSR.
c. Table 3: Determines if your MWQP meets PSR criteria and if microbial die-off is required. Table 3 will only appear after one or more samples have been added.

CAUTION: Even though GM and STV values appear on the Results screen, using fewer than the PSR-required number of samples to calculate your MWQP does not satisfy the requirements of the rule.

Important Notes: If your MWQP does not meet the Produce Safety Rule criteria then one option for using this water is to apply an interval (up to a maximum of 4 days) between application of the water and harvest of that crop. The die-off interval is calculated based on a decline rate of 0.5 log CFU/day. If applicable, the greater of the two values from Table 3 should be used.

If you have determined or have reason to believe that your MWQP no longer represents the microbial quality of your water, you must develop a new MWQP reflective of the time period in which you believe your MWQP changed. It is your responsibility to modify your water use or apply necessary mitigation steps to remain compliant with the FSMA PSR.

This tool calculates your ground water Microbial Water Quality Profile (MWQP). Per the PSR, a minimum of 4 samples are required to obtain a valid MWQP.

Initial MWQP:
1. Collect at least 4 water samples that are representative of use and collected as close as is practical to harvest. These samples must be collected over a minimum period of 1 year, and not greater than 1 year.
2. Analyze water samples to quantify generic E. coli/100 ml (usually by a testing service).
3. Enter water sample collection date in the first text box below.
4. Enter water sample collection location description or ID in the second text box.
5. Select the sample stage as Initial.
6. Enter E. coli lab results (E. coli CFU/100ml) in the fourth text box. Note: If your sample result is below the limit of detection at LOD <1 (or zero) generic E. coli CFU/100 ml), enter 1.
7. Add Notes if necessary (eg. rainy day, cloudy water, low flow). Press "Add" Note: Samples will appear by date in Table 1.
8. Repeat step 3 to 7 until you have entered 4 samples.
9. Review each table to determine your Geometric Mean (GM), Statistical Threshold Value (STV), and compliance with Produce Safety Rule (PSR) requirements:
a. Table 1: Displays Your Microbial Water Quality Profile (MWQP) in the bottom two rows. The GM and STV are your MWQP.
b. Table 2: Displays Your MWQP Results Compared to the PSR microbial water quality criteria.
c. Table 3: Determines if your MWQP meets PSR criteria and if microbial die-off is required. Table 3 will only appear after one or more samples have been added.

Annual Survey
Following establishment of your initial MWQP, update your MWQP annually as follows:
1. Collect at least 1 water sample that is representative of use and collected as close as is practical to harvest.
2. Analyze water samples to quantify generic E. coli/100 ml (usually by a testing service).
3. Enter 1 current year sample values as described above in Step 3 to Step 7. For Sample Stage, choose Annual instead of Initial.
4. Review each table to determine your Geometric Mean (GM), Statistical Threshold Value (STV), and compliance with Produce Safety Rule (PSR) requirements:
a. Table 1: Displays Your Microbial Water Quality Profile (MWQP) in the bottom two rows. The GM and STV are your MWQP.
b. Table 2: Displays Your MWQP Results Compared to the PSR.
c. Table 3: Determines if your MWQP meets PSR criteria and if microbial die-off is required. Table 3 will only appear after one or more samples have been added.

CAUTION: Even though GM and STV values appear on the Results screen, using fewer than the PSR-required number of samples to calculate your MWQP does not satisfy the requirements of the rule.

Important Notes: If your MWQP does not meet the Produce Safety Rule criteria then one option for using this water is to apply an interval (up to a maximum of 4 days) between application of the water and harvest of that crop. The die-off interval is calculated based on a decline rate of 0.5 log CFU/day. If applicable, the greater of the two values from Table 3 should be used.

If you have determined or have reason to believe that your MWQP no longer represents the microbial quality of your water, you must develop a new MWQP reflective of the time period in which you believe your MWQP changed. It is your responsibility to modify your water use or apply necessary mitigation steps to remain compliant with the FSMA PSR.