[11]Per email correspondence from Karen Brown, DWR – 1/2/03

Figure  SEQ Figure \* ARABIC 26 – Well Count and Average Density Map by Township/Range-Section

Upper Finegold Watershed Ground water Quantity – Phase 2

As indicated for Phase 1, the Department of Water Resources (DWR), San Joaquin District in Fresno intended on developing a relational database of well logs for their district.  During Phase 2 it was proposed to DWR and accepted, that MAWC would dedicate resources to computer input well logs that were within the Upper Finegold Watershed – and subsequently for the complete MAWC study area under Phase 3.  Based upon a multi-agency agreement between the San Joaquin Regional Water Resources Control Board and the California Department of Water Resources – personnel were assigned to this effort through MAWC and over 1,060 logs were inputted of which 836 ultimately were determined to be within the Upper Finegold Watershed study area.  At all times, the confidentiality of the information regarding private ownership and specific well data were adhered to.  Towards the end of this program, the California Water Institute of California State University, Fresno (CWI-CSUF) provided personnel through MAWC to conclude inputting well log data into DWR’s relational database as a part of Phase 3. 

Indicative of maintaining confidentiality, data specificity is at the Township/Range and Section (TRS) Level (1 square mile) and on an aggregate basis.  Quantitative figures at the TRS level are averages.  MAWC worked with CWI-CSUF to develop a Geographical Information System (GIS) base map of the Upper Finegold watershed illustrating quantitative well log information derived from DWR’s relational database. 

This analysis[12] is intended to be a first general effort to understand the groundwater situation within the Upper Finegold Watershed and the Millerton Area Watershed project area overall. Never the less, the structural geology of the area, which is a very important element for the study of aquifers in fractured rock, is not considered here. 

According to the well log records inputted into the Department of Water Resources (DWR) relational database, the Upper Finegold watershed study area contains 836 groundwater wells, drilled from 1955 to 2003.  Most of them are for domestic use with a wide range of depths from six (6) feet to 1,250 feet. Their discharges vary from 0.125 (1/8) gpm (gallons per minute) to 500 gpm.

[12] Analysis provided by Nelson Bernal, Graduate Research Student, California Water Institute – CSUF 

Methodology of Initial Analysis

As noted above, 836 wells were used to obtain the data required to construct the GIS-based maps and determining the relationships among some parameters that are common to every single well such as: completion date, depth and yield. 

The data was filtered in order to obtain a representative homogenous population. The spatial analysis performed was related to the average values calculated per section. This is because in the original data base these wells didn’t have a defined coordinate system, but they were related to specific sections. Therefore, using GIS software (ArcView), a coordinate value was calculated for every section; then in order to get average numbers, the same coordinate value was assigned to wells related to the same section. 

As result of the spatial analysis, three layers were constructed representing the spatial distribution of well completion date, depth and yield. This is the order of the different layers in the layout map:

1. Well location

2. Township/Section net

3. Upper Fine Gold Parcels

4. Spatial analysis

Well Completion date

Well depth

Well yield

Results of Initial Analysis

Average Well Completion Date per Section

Figure  SEQ Figure \* ARABIC 27 - Average Date in which wells were completed in the Upper Finegold Watershed

This analysis is perhaps the most general because the well distribution is determined randomly, as a consequence the oldest well, drilled in 1955, is not the lowest value represented in figure 2, and instead the range 1980 – 1981 appears representing the sections with the oldest wells in the watershed. These results must be seen and understood as the general value for every section. For instance, section 35 of the township 08S, range 21E contains the oldest wells in the watershed as well as section 28 of township 07S, range 22E. The most recent wells were drilled in section 10, township 08S, range 21E to the west and section 14, township 08S, range 22E to the East.

Average Well Depth per Section

Figure  SEQ Figure \* ARABIC 28 - Average Well Depth in the Upper Finegold Watershed

This map represents the distribution of average depths in the Upper Finegold Watershed, according to this interpretation the deepest wells are located to the North and Southwest areas of the watershed, the shallowest wells are locate to the West. It is to emphasize that both layers completion date and well depth overlap very well, this could mean that the youngest wells in the watershed are also the deepest, located to the North and Southwest of the watershed. The deepest and oldest wells are located to the West.

Average Well Yield per Section 

In this map the wells located in the West side of the watershed, represent intermediate and high discharge values. Overlapping the other two maps, it is possible to observe that the Southwest area with the most recent and deepest wells produces the highest discharges. In contrast, the oldest wells located to the East, produce the lowest discharges in the Upper Finegold Watershed. 

This map also appears to illustrate that the well yields appear to be less within the areas of higher parcel densities.  Additionally these locations also appear to be in areas of greater elevations and thus may be an indication of the underlying geology (more fractured rock versus alluvial areas).

Figure  SEQ Figure \* ARABIC 29 - Average Well Yield in the Upper Finegold Watershed

Figure  SEQ Figure \* ARABIC 30 - Well Density by Township/Range and Section in the Upper Finegold Watershed

This map illustrates what the well density is by Township/Range and Section.  As can be observed by this map is that the greatest well densities by Section (640 acres) correlate to where the most parcels are within the watershed.  These parcels primarily represent residential areas in which most require their own domestic well as their source of water.  Well densities are scaled from one well per 640 acres (Section) – down to one well per two acres on average within a section. 

Observation from Analysis of Spatial Data

As an outcome of the initial spatial analysis performed, it is possible to conclude that there is clear correlation among the data studied.  However, it is important to point out that the aquifers that are being intersected by the wells in the watershed are not continuous and their distribution is related to the dominant fracture system in the area. That’s why it is very important to understand the underlying structural geology of the Upper Finegold Watershed and determine, in a more detailed spatial analysis, if the relationships suggested here have any hydro-geological basis.

Ground Water Quality

The quality of ground water within the watershed study area has not been evaluated in great detail.  Individual wells for private use are not required to be tested for drinking water quality standards.  Therefore, it is difficult to determine if the ground water is naturally affected by drinking water quality constituents – or impacted by man-made sources such as wells in close proximity to septic/leach systems. 

In respect to the watershed in eastern Madera County the Todd Report includes water quality test results for primary constituents of interest related to drinking water quality.  The analysis and relevancy to determining the overall quality of well water for domestic purposes is not fully known.  However indirectly, water quality information regarding exceeding drinking water standards for community systems such as Hillview[13] and Broadview Terrace related to Gross Alpha (radioactivity) in the Oakhurst area convey some level of relevance to the Millerton Watershed. 

Within the watershed in Fresno County, a list of water systems that are overseen by the Environmental Health Department has been provided and are noted in the Appendices.  Similar to the Oakhurst area, information has been obtained indicating that drinking water standards – in particular Gross Alpha may – or has been exceeded.  The most noteworthy appears to be drinking water quality for Gross Alpha that has exceeded US EPA standards for community wells at the Big Sandy Rancheria in Auberry.[14]

Upper Finegold Well Water Quality Analysis under Phase 2

Figure  SEQ Figure \* ARABIC 31 - Typical well, pump, pressure tank & storage configuration

Under Phase 2 activities, MAWC collaborated with the Public Health Laboratory under Fresno County’s Department of Community Health to have private wells analyzed for drinking water quality on a voluntary basis.  The foundation for this program was developed by the Madera County Department of Environmental Health directly with the Fresno County Public Health Laboratory as a county-wide voluntary program.  However, it was the responsibility of the well owner to obtain the sampling containers and to perform the collection of the water samples per the written instructions provided by the Madera County Health Department.  Finally, it was the sole responsibility of the well owner to then deliver the samples to the Madera County Health Department. 

Within the Upper Finegold Watershed, by mailing a notification to each individual landowner, this service was offered.  However, in this case the landowner was not responsible for performing any of the work – or to follow established protocols (instructions); assuring full quality control of samples collected;  maintaining the chain of custody; nor having to transport the samples in cool storage within the designated times directly to the Fresno County Public Health Laboratory.  All of these steps were performed by MAWC personnel trained by the Health Lab.  This service provided MAWC the opportunity to ascertain if there may be any potential groundwater quality hazards within the Upper Finegold Watershed.  The following map indicates where scheduled samplings of raw well water based upon landowner permission were to occur based upon general proximity and parcel densities.

Figure  SEQ Figure \* ARABIC 32 - Upper Finegold Watershed Well Water Sampling under Phase 2

Potential constituents of concern that may exceed Maximum Contaminant Levels (MCL) analyzed by the Lab fell into three groupings:

1.      Bacterial – Total Coliform

2.      General Mineral, Physical and Inorganic Chemistry Analysis

3.      Radiological

Bacterial analysis was a basis to determine if there was any influence of septic/leach line and well water quality.

General Mineral, Physical and Inorganic Chemistry analysis focused on raw water quality and subsequent plumbing systems within a domestic household:

· Aluminum

· Arsenic

· Copper

· Fluoride

· Iron

· Lead

· Manganese

· Nitrate

· pH 

Radiological was an analysis of raw well water for Gross Alpha.

Table  SEQ Table \* ARABIC 10 - Table of Constituents of Concern with Maximum Contaminant Levels Exceeding Drinking Water Quality Standards based upon sampling sites

Figure  SEQ Figure \* ARABIC 33 - Map Showing Constituents Analyzed Exceeding MCLs or Secondary Standards

As can be seen by this map, the area along eastern part of the watershed shows incidences of iron and manganese.  These constituents are classified under secondary drinking water quality standards.  Additionally, arsenic and gross alpha have been analyzed as exceeding established drinking water quality levels standards – or MCLs (Maximum Contaminant Levels) in at least one location for each.  Other areas of the watershed where well water was analyzed remained below the MCLs.

Figure  SEQ Figure \* ARABIC 34 - Preparing to collect well water samples

Consumptive Water Use

Unlike surface water appropriations and allocations, it is very difficult to ascertain what the consumption is of ground water.  Owners of private wells are not required to monitor the amount of water used through metering devices.  Public wells may have data that can be used to estimate water usage.  In the case of the Todd Engineers groundwater report for eastern Madera County, there is information on specific community and county wells and their annual production. 

Figure  SEQ Figure \* ARABIC 35 – Well Site in the Upper Finegold

Subsequent to the publication of the Phase 1 watershed assessment in February, 2004, the San Joaquin District of the Department of Water Resources re-issued their analysis of groundwater usage.  It was determined that the foothill area of the region was in a net usage of groundwater.  Therefore, this could infer a gradual downward trend in the amount of water in a fractured rock area. 

Figure  SEQ Figure \* ARABIC 36 - Close-up of a Wellhead

For Phase 2, in the case of the Upper Finegold Watershed, there was no concerted effort to determine specific trends of ground water.  This would have required access to wells and the ability to determine the current static water level – and then to compare historic information – or to monitor the wells over time.  

However, for Phase 3 an effort will be conducted through the isotopic analysis of precipitation, surface water (streams and ponds) and groundwater sources (i.e. wells and springs) to determine what the hydrological cycle may be.  This investigation with be conducted between MAWC and the California Water Institute – California State University, Fresno in 2005 and 2006.

Figure  SEQ Figure \* ARABIC 37 - A Pump that has failed
 

Summary of Findings – Phase 1

1.      The Millerton watershed is exclusively a non-groundwater basin region as recognized by the State of California Department of Water Resources (DWR) Bulletin 118 – California’s Groundwater. 

2.      Issues related to groundwater reliability in the area have been recognized and predicted since the publication of Bulletin 135 – Madera Area Investigation in 1966. 

3.      State mandated County Groundwater Management Plans under AB3030 do not include non-groundwater basins such as the Millerton area watershed. 

4.      The Todd Engineers Technical Memorandum Groundwater Conditions (of) Eastern Madera County provides general principles that could be applied for an area-wide analysis. 

5.      Groundwater usage for domestic, agriculture and other uses is not regulated or metered. 

6.      The Millerton area watershed geological composition is non-alluvial and consists primarily of fractured granitic “bedrock”. 

7.      Less than two percent (2%) of the fractured rock may contain water by volume versus 10-15% for an alluvial ground water basin. 

8.      Numerous investigations from 1966 to present have attempted to quantify the amount of ground water available, its sustainability – however, the results of the investigations cannot be generalized throughout the watershed. 

9.      Long-term trends may be able to be extrapolated – however, no comprehensive programs have been established to ascertain the baseline and trends. 

10.  Comparative analysis may be possible – but, have limited predictive capabilities. 

11.  The Oakhurst region of Madera County adjoining the Millerton watershed has significant water quantity and quality issues. 

12.  There is some information in the Fresno County portion of the Millerton watershed in which well “problems” appear to be occurring. 

13.  Currently, well information available from DWR for analysis is limited due to concerns of confidentiality. 

14.  Water quality information is limited to community systems.  Individual systems are not required to be tested for drinking water standards. 

15.  Minimum water quality standards are being exceeded for gross alpha by some community systems (Hillview and Broadview Terrace, Oakhurst) adjoining the watershed.  In Fresno County the Big Sandy Rancheria of the Auberry area appears to exceed standards for radiation.

Summary of Findings for Upper Finegold Watershed based upon field monitoring and surveys – Phase 2 

1.      No known studies on groundwater quantity have been performed within the Upper Finegold Watershed. 

2.      No anecdotal information was provided regarding groundwater availability within the Upper Finegold Watershed. 

3.      Well yields appear to be less in the eastern portion of the Upper Finegold.  This is also the area with the greater concentration of wells based upon land use activities. 

4.      Based upon initial review, earlier wells drilled appear to be of a shallower depth than more recently drilled wells. 

5.      Groundwater trends can not be determined solely based upon depths of wells and their concentration. 

6.      The breadth of constituents of concern cannot be determined by limited sampling of raw well water – only the identification of potential “pockets” in which the maximum contaminant levels (MCLs) may have been exceeded for drinking water quality.

Conclusions – Phase 1 

1.      Problems within adjacent areas suggest the potential for problems within the Millerton watershed. 

2.      The rate of ground water consumption and its quality has not been ascertained within the Millerton watershed. 

3.      There is no area-wide program within the Millerton watershed to baseline, monitor and analyze groundwater quantity trends for community and private wells. 

4.      There is no area-wide program within the watershed to analyze and monitor individual private wells for water quality. 

5.      While there may be individual wells being monitoring, there is no area-wide program within the watershed that ascertains a groundwater profile for the watershed with emphasis in the more populated clusters. 

6.      Even if there were area-wide programs within the watershed for monitoring ground water quantity and quality, there are not structures in place to share this information. 

7.      There is no data sharing, educational or outreach program or information clearinghouse that could provide two-way communication to individuals and groups regarding groundwater quality and quantity within the watershed.

Conclusions – Upper Finegold Phase 2 

1.      Phase 1 conclusions are relevant to the Upper Finegold watershed as a subset. 

2.      Initial data gathered demonstrates the feasibility to conduct larger scale investigations focused on groundwater quantity and quality. 

3.      Groundwater is the only known source of water available within the Upper Finegold Watershed for domestic use (M&I). 

4.      Detections of constituents of concern that were analyzed exceeding the established MCLs (Maximum Contaminant Levels) - in particular arsenic and gross alpha may warrant a more thorough investigation. 

Go to Section 4