Groundwater Quality Monitoring and Reporting

Monitoring of domestic wells is necessary to protect public health, identify domestic water wells that do not meet drinking water standards, provide timely health risk notifications, and verify well user have alternative replacement water as appropriate. Each year, growers must provide well users with a summary of laboratory analytical results with 3 business days of receiving results. Growers must also provide a summary of the most recent laboratory analytical results to any new well users within 3 business days when there is a change in population using the well. Growers must update their electronic Notice of Intent (eNOI) within 30 days of receiving results to confirm that well users have been provided with a summary of laboratory results, informed of any health risks associated with well water containing nitrate and/or 1,2,3-TCP, have an alternate source of water for domestic purposes if appropriate, and to confirm that any new well users have been provided with the most recent laboratory analytical results.

• Template for download: Summary of Laboratory Sample Results for On-Farm Domestic Well Users (English | Español | 中文)
• Instructions for Growers: Summary of Laboratory Sample Results for On-Farm Domestic Well Users (English | Español | 中文)

Primary irrigation well monitoring must be completed annually until a groundwater quality trend monitoring and reporting workplan is approved and initiated. The objectives of sampling on-farm irrigation wells are to evaluate groundwater conditions in agricultural areas and to inform establishment of a groundwater quality trend monitoring network.

Growers must conduct groundwater quality trend monitoring and reporting, either individually or via membership in a third-party program. The objectives are to evaluate the status of groundwater quality over time, including short-term patterns and long-term trends, and to quantitatively evaluate the impact of irrigated agricultural waste dischargers to groundwater.

Third-Party Program Workplans

Central Coast Water Quality Preservation, Inc. (Preservation, Inc), an approved third-party program administrator under the Agricultural Order, has indicated that they will submit a workplan for groundwater quality trends. The groundwater quality trend work plan for third-party programs is due September 1, 2023 for groundwater basins within Groundwater Phase 1 areas; September 1, 2025 for groundwater basins within Groundwater Phase 2 areas; September 1, 2027 for all other areas. Once third-party program workplans are approved for Groundwater Quality Trends the workplans will be available here. Stay tuned for more information!

Individual Growers

Individual growers that are not part of a third-party program must complete groundwater quality tend monitoring and reporting themselves and report directly to the Central Coast Water Board. In most cases individual growers will incur greater costs than third-party program members to conduct groundwater trends monitoring and reporting. Specifically, individual growers are required to comply with the following:

1. All groundwater monitoring data sampled must meet the minimum groundwater monitoring requirements of the Order and be submitted electronically to the State Water Board’s GeoTracker database by the testing laboratory. Submitted data must include the ranch AGL, the well coordinates (latitude and longitude), the well name (i.e., Location Identifier (LOCID)/Field Point Name) that is consistently and repeatedly used to refer to the same well each time the well is sampled, and the well type (i.e., Field Point Class; PRIW for Domestic/Private Drinking Water Well or AGIR for Agricultural/Irrigation Well). It is recommended the well name be affixed to the well to eliminate confusion during sample collection and labeling and laboratory reporting.
2. All groundwater samples must be collected by a qualified third party (e.g., consultant, technician, person conducting third-party monitoring) using proper sample collection and handling method, chain-of-custody, and quality assurance/quality control protocols associated with monitoring and reporting.
3. To ensure the collection of representative groundwater samples, all groundwater samples must be collected once field parameters stabilize (i.e., pH: ± 0.1, specific conductance: ± 3 – 5%, and temperature: ± 3%).
4. Submit an individual groundwater quality trend monitoring work plan to the Executive Officer for approval prior to implementation. Growers must submit the work plan by the following dates:
1. September 1, 2023 for ranches groundwater basins with Groundwater Phase 1 areas;
2. September 1, 2025 for ranches groundwater basins with Groundwater Phase 2 areas;
3. September 1, 2027 for ranches in all other areas.
5. At a minimum, the work plan must include the following:
1. Identification and description of wells used for groundwater quality trend monitoring (in narrative form and in map view) with supporting technical rationale justifying the effectiveness of the well(s) in assessing ranch level groundwater quality trends over time.
2. Identification of the water-bearing zone monitored by each well used for groundwater quality trend monitoring.
3. Proposed location(s) and well construction characteristics for any proposed new purpose-built monitoring wells to be used in groundwater quality trend monitoring if existing wells are not adequate for long-term monitoring.
4. Determination of the statistical method that will be used for groundwater quality trend evaluation.
6. The monitoring and reporting schedule and minimum list of testing parameters is shown in Table MRP-8.
7. Growers must monitor wells. used in groundwater quality trend monitoring on a semi-annual basis during the first and third quarters of each calendar year. Monitoring data must be reported to GeoTracker by May 31 for sampling occurring in the first quarter and by November 30 for sampling occurring in the third quarter.
8. Growers must submit a groundwater quality trend evaluation report by January 31 each year. The groundwater quality trend evaluation report must be provided in a format specified by the Executive Officer.
9. At a minimum, the groundwater quality trend evaluation report must include the following:
1. For each well used in groundwater quality trend monitoring, plots of concentration versus time for each monitoring parameter, except for field parameters pH, temperature, and specific conductance. The groundwater quality trend plots must reflect concentrations detected during each sampling event and are expected to expand over time.
2. Discussion of groundwater quality trends represented in the trend plots (i.e., increasing or decreasing groundwater quality trends, implications associated with farm management practices, etc.).
10. Growers who do not have a well on their property and do not choose to join a third-party program must still perform groundwater quality trend monitoring and reporting in accordance with Table MRP-8. Growers who do not have a well on their property may choose one of the following options for groundwater quality trend monitoring and reporting:
1. Install a monitoring well or wells as needed to sufficiently characterize groundwater quality trends.
2. Develop a coordinated groundwater quality trend monitoring and reporting program by partnering with adjacent property owner(s) with wells to sufficiently characterize groundwater quality trends.
3. Obtain authorization from adjacent property owners with one or more wells to collect water quality samples from their well or wells.
4. Obtain authorization from individual property owners or a third-party groundwater quality trend monitoring and reporting program to utilize their water quality data.

The conditions of “authorization” will be up to the negotiating parties, and documentation of the authorization will be a condition of the individual trend monitoring program work plan approval process.

11. Growers who obtain authorization from individual property owners (including adjacent property owners) or a third-party program for use of water quality data must document in the annual groundwater quality trend evaluation report how data obtained from wells not on the Discharger’s property are representative of groundwater conditions at the Discharger’s property.

Based on groundwater quality data or significant and repeated exceedance of the nitrogen discharge targets or limits in the Agricultural Order, growers may be required to conduct ranch-level groundwater discharge monitoring and reporting. Growers that are members in good standing with a third-party alternative compliance program are exempt from this requirement.