# Ag Water > Calculates agricultural water microbial quality profiles for Produce Safety Rule compliance. (iPhone/iPad app by University of Arizona.) - Source: https://appshunter.io/ios/app/ag-water/id1115338059 (this page in markdown: same URL + `.md`) - Developer: [University of Arizona](https://appshunter.io/developer/437682109) - Category: Utilities, Education - Price: Free - Rating: 1.00/5 from 2 App Store ratings - Age rating: 4+ - Requires: iOS 15.4 · 5 MB - Languages: American English - Released: 2016-05-20 - Data updated: 2026-06-10 - Monetization: free - User reviews in markdown: https://appshunter.io/ios/app/ag-water/id1115338059/reviews.md ## What is Ag Water? *OVERVIEW* The Produce Safety Rule (PSR) requires growers to initially establish a Microbial Water Quality Profile (MWQP) for each untreated surface agricultural water source used during growing activities of covered produce (other than sprouts). The PSR must be applied for each water source using a direct water application method and annual surveys must be conducted for that water source in subsequent years. The water quality profile is based on the levels of generic E. coli in your agricultural water. The method of testing for generic E. coli must be conducted following U.S. Environmental Protection Agency (EPA) Method 1603. Methods other than 1603 may be used but they must be scientifically valid and shown to be at least equivalent to EPA Method 1603 in accuracy, precision, and sensitivity. Ag Water app was developed to: • Assist growers with GM and STV calculations to determine if their water meets the criteria for appropriate application to produce before harvest • Assist growers with making water management decisions if their water does not meet the criteria in the Produce Safety Rule • Evaluate current sampling conditions for irrigation water quality to determine the probability of microbial contamination *Definitions:* Agricultural water is defined in part "as water that is intended to, or likely to, contact the harvestable portion of covered produce or food-contact surfaces." Geometric mean (GM): GM is essentially the average amount of generic E. coli in your water source. PSR criteria requires a GM at or below 126 E. coli CFU/100ml. Statistical threshold value (STV): STV is a measure of variability of generic E. coli levels in your water source. In simple terms, it is the level where 90 percent of the samples (log values) are below the value. PSR requires an STV at or below 410 E. coli CFU/100ml CFU (colony forming units) is the estimate of bacterial concentration in your water per 100 ml. More information on the Produce Safety Rule and agricultural water can be found here: http://www.fda.gov/Food/GuidanceRegulation/FSMA/ucm334114.htm *MICROBIAL WATER QUALITY PROFILE* This feature allows you to determine your MWQP. The initial MWQP must be established with a minimum of 20 water samples that are representative of use and collected as close to harvest as possible over a period of at least 2 to a maximum of 4 years. Geometric mean (GM) and Statistical Threshold Value (STV) are calculated from these 20 samples (minimum). The GM and STV are your MWQP and should be compared to the microbial quality criteria provided in the Produce Safety Rule. After the initial MWQP has been established, the GM and STV values must be updated annually based on a minimum of 5 new samples. "Rolling" GM and STV values are calculated by combining the old and new sample data. For example, for an MWQP established with 20 samples, five new samples would be combined with the most recent 15 samples from the previous MWQP to update the MWQP and confirm that the water is still being used appropriately. *CURRENT WATER SAMPLING CONDITIONS* This feature will evaluate current environmental conditions to determine the potential for microbial contamination in a water source. The probability of contamination is determined using environmental data, current weather conditions, and user data input which includes water quality parameters specific to the water source in question. ## Key features - Geometric Mean (GM) calculations - Statistical Threshold Value (STV) calculations - Microbial Water Quality Profile (MWQP) determination - Water management decision assistance - Evaluation of irrigation water quality sampling conditions ## Frequently asked questions about Ag Water ### What is Ag Water used for? Ag Water assists growers in calculating Geometric Mean (GM) and Statistical Threshold Value (STV) for their agricultural water sources. This helps determine if the water meets the criteria set by the Produce Safety Rule for application to produce before harvest. ### How does Ag Water help with Produce Safety Rule compliance? The app facilitates the establishment and annual updating of a Microbial Water Quality Profile (MWQP) by calculating GM and STV. These values are compared against the microbial quality criteria required by the Produce Safety Rule. ### What are the minimum sample requirements for Ag Water? For the initial MWQP, a minimum of 20 water samples are required. For annual updates, a minimum of 5 new samples are needed, combined with the most recent data from the previous MWQP. ### What is the GM and STV criteria for the Produce Safety Rule? The Produce Safety Rule requires a Geometric Mean (GM) at or below 126 E. coli CFU/100ml and a Statistical Threshold Value (STV) at or below 410 E. coli CFU/100ml for agricultural water. ### Is Ag Water available on multiple devices? Ag Water is available for iPhone, iPad, and iPod devices, as indicated by its supported devices list. It is designed for Apple's mobile operating system. ### How often is Ag Water updated? The app was last updated on April 26, 2022, with version 1.3 being the latest release. This indicates a moderate update frequency for the application. ### What is the user rating for Ag Water? Ag Water has a rating of 1.0 stars based on 2 ratings. This suggests a very low user satisfaction based on the limited feedback available. ### Does Ag Water have ads? No, Ag Water does not contain advertisements. The app is free to download and use without any ad interruptions. ## Version history (last 5 releases) ### 1.3 — 2022-04-26 Updated for the latest version of iOS. ### 1.2 — 2016-09-30 This app has been updated by Apple to display the Apple Watch app icon. Updated for iOS 10! Minor bug fixes. ### 1.1.2 — 2016-07-12 Minor bug fixes. ### 1.1.1 — 2016-07-12 Minor bug fixes. ### 1.1 — 2016-06-16 Minor bug fixes. ## Apps similar to Ag Water | App | Rating | Price | Category | | --- | --- | --- | --- | | [BedBugID](https://appshunter.io/ios/app/bedbugid/id1540150153) | 5.0 (4) | Free | Utilities | | [WorkPass by Plume](https://appshunter.io/ios/app/workpass-by-plume/id1559674293) | 3.6 (14) | Free | Utilities | | [x8](https://appshunter.io/ios/app/x8/id1672854718) | — | Free | Utilities | | [Scrollengine - Local Delivery](https://appshunter.io/ios/app/scrollengine-local-delivery/id1594125429) | 5.0 (2) | Free | Utilities | | [Pomodoro Focus Timer Plus](https://appshunter.io/ios/app/pomodoro-focus-timer-plus/id6446323528) | — | Free | Utilities | | [DIGIMobile V2](https://appshunter.io/ios/app/digimobile-v2/id900320479) | 1.5 (6) | Free | Utilities | ## More apps by University of Arizona - [University of Arizona](https://appshunter.io/ios/app/university-of-arizona/id437682106) - [UAGC Talon Mobile](https://appshunter.io/ios/app/uagc-talon-mobile/id440722504) - [Constellation for UAGC](https://appshunter.io/ios/app/constellation-for-uagc/id444832035) - [Chemistry By Design: Target Synthesis Database](https://appshunter.io/ios/app/chemistry-by-design-target-synthesis-database/id451791347) - [UAGC Talon Tablet](https://appshunter.io/ios/app/uagc-talon-tablet/id467730770) - [UAbacus](https://appshunter.io/ios/app/uabacus/id688547692) All apps by University of Arizona: https://appshunter.io/developer/437682109 --- *Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-06-10.*