COMMENTS ON THE DRAFT AQUIFER PROTECTION PERMIT

FOR THE PHELPS DODGE SIERRITA INC. (PDSI) MINE

Introductory Comments

Note: For more detailed supporting information see the Background Information and Supporting Documentation discussion beginning on page 6 of this document.

The Community of Green Valley

Green Valley is a retirement community. Our population demographics are very different than the United States as a whole. For example, based on information from the 2000 Census:

In the United States, the average age is 35.3 years. In Green Valley, it is 72.2 years.

In the U.S., 28.6% of the population is under the age of 20. In Green Valley, only 1.8% are that young.

In the U.S., only 5.9% of the population is age 75 and older. In Green Valley, 39.2% of us are in that age range.

Green Valley residents retired from a wide range of backgrounds, moved here from each of the 50 states, the District of Columbia, and some from other countries. This diversity provides a wide-ranging variety of experiences and cultures, which, in turn, can produce a wide range of opinion on any issue facing the Community at any given time.

If it is true that as we age we become more sensitive to factors that influence our health, we have a much larger “sensitive population” percentage than the US average.

Community Concerns

Over the past 10 years, some residents living in the part of Green Valley served by Community Water Company have been exposed to increasing concentrations of Sulfates and Total Dissolved Solids (TDS) in their tap water. These contaminants are believed to be associated with a “Sulfate Plume” entering the Upper Santa Cruz Basin aquifer from the Tailing Impoundment at the Phelps Dodge Sierrita Incorporated (PDSI) Mine located west of Green Valley. To date, this Sulfate Plume has impacted two of Community Water’s four production wells.

To their credit, PDSI has worked with Community Water Company to provide a solution to the Sulfate problem. As a “temporary solution”, Community Water is accepting water from three PDSI wells located in their Esperanza Wellfield. This has allowed Community water to discontinue use of wells 7 and 8, the two wells impacted by the “sulfate plume.” Therefore, Community Water customers are no longer receiving water containing high sulfates and TDS.

PDSI and Community Water are continuing to work together to come up with a “permanent solution.” This “permanent solution” appears to be based on a strategy of installing new wells as far from the plume as possible, or “running from the plume.”

The Regulatory Climate

1. Federal Documents and Requirements

The United States Environmental Protection Agency (USEPA) has not established mandatory health-based standards called Maximum Contaminant Levels (MCLs) for Sulfates and TDS because they are not considered to be hazardous substances. Rather, USEPA established recommended, but non-enforceable Standards, called Secondary Maximum Contaminant Levels (SMCLs) that reflect the aesthetic (taste and odor) properties of Sulfates and TDS, and are not health-based, enforceable standards. These SMCLs are 250 mg/L for sulfates and 500 mg/L for TDS.

The United States Environmental Protection Agency (USEPA) and the Centers for Disease Control (CDC) studied the health effects of Sulfates, and published reports on that subject. Basically, the conclusion was that sulfates do have a laxative effect. The laxative effect is dependent on the specific sulfate compound present (for example, Magnesium Sulfate has a stronger laxative effect than Sodium Sulfate). Also, there are sub-groups within the population that are more sensitive to sulfates – namely infants starting on formula mixed with water, and the elderly and invalids who take nutritional supplements mixed with water. Visitors who aren’t accustomed to water with high sulfates may experience a laxative effect upon exposure to water with high sulfate concentrations, but they become acclimated after 7 to 10 days. The specific language within these documents that describes the groups that acclimate to Sulfates is not consistent. This inconsistency only feeds the concerns, confusion, and emotional responses from within the community.

There is one other relevant point provided by resident of the Green Valley area who has extensive credentials in groundwater behavior and contaminant plumes from mining operations.

“It is fair to say that although Sulfates may not be a major health concern from a regulatory perspective, it is common knowledge within the mining industry that in groundwater contaminant plumes the metals follow the sulfates. Sulfates are the harbingers of things to come.”

CONCLUSION: The metals present in the “sulfate plume”, and their concentrations have not been adequately defined. Therefore, the health effects from ingestion of sulfates in the aquifer cannot be completely defined, and the metals “in the pipeline” have not been identified.

The draft APP does not address these deficiencies.

There is one additional USEPA regulatory standard that is a factor: the new Arsenic drinking water standard of 10 ppb that becomes effective in 2006. Both Community Water and Green Valley Water District have production wells that exceed this standard. Information contained in the Arizona Arsenic Master Plan (the AAMP) published by ADEQ, states that high concentrations of Sulfates and TDS interfere with Arsenic Treatment Technologies. The AAMP defines “high” concentrations as >200 mg/L for Sulfates, and >750 mg/L for TDS. The two water companies should provide information on the Sulfate and TDS threshold concentrations for the specific technologies being applied to their specific circumstances. Absent that information, the information from the AAMP of 200 mg/L for Sulfates, and 750 mg/l for TDS should be applied.

Both Community Water and Green Valley Water District are actively engaged in the selection and installation of Arsenic Treatment technologies. Community Water has installed Arsenic Treatment facilities at Well 9, and the installation at Well 6 is under construction. The Sulfate Plume has not impacted Well 6 and Well 9 yet, but Well 6 is about 0.6 mile from Well 8, and Well 9 is about 0.8 mile from Well 7. These are not big distances when compared to the distance the plume has traveled to reach Community Water Wells 7 and 8.

So, we have a situation where the presence of a non-hazardous substance (Sulfates) has the very real potential to interfere with the ability to comply with an enforceable standard for a hazardous substance (Arsenic).

2. State of Arizona: Arizona Revised Statutes, Title 49–244.3 Point of Compliance.

For pollutants that are not hazardous substances the director, in identifying a point of compliance, shall take into account the volume and characteristics of the pollutants, the practical difficulties associated with implementation of applicable water pollution control requirements, whether the facility is a new facility or an existing facility, water conservation and augmentation and the site-specific characteristics of the facility, including, but not limited to, climate hydrology, geology, soil chemistry, and pollutant levels in the aquifer. The point of compliance must be so located as to ensure protection of all current and reasonably foreseeable future uses of the aquifer.

CONCLUSION: Points of compliance for the aquifer used to provide drinking water to Green Valley must ensure the use of the aquifer for drinking water, and the requirement to treat that water to meet the 10 ppb MCL for Arsenic. The alert levels established for Sulfate at a Point of Compliance should not exceed the 200 mg/L threshold established by the ADEQ AAMP.

Use Protection Limits and Alert Levels

Paragraph 2.6.2.3.3 of the draft APP (page 18), states that ADEQ has established a Use Protection Limit for Sulfate at ESP-4 of 400mg/L, an Interim Alert Level for Sulfate at CW-8 of 650 mg/L, and references the ADEQ Substantive Policy Statement “Using Narrative Aquifer Water Quality Standards to Develop Permit Conditions for Aquifer Protection Permits”. To date, we have been unable to get information on Sulfate concentrations at ESP-4, and have been unable to obtain a copy of the referenced ADEQ Substantive Policy Statement. We can only comment as follows:

1. No information is provided as to how the Use Protection Limit of 400 mg/L was determined. Based on the need for Arsenic treatment, a Use Protection Limit no greater than 200 mg/L is the proper choice.

Alert Levels are apparently determined by applying Statistical Methods to available data for the specific location selected. Then, what is known as an “upper confidence limit” is calculated. This calculated upper confidence limit becomes the Alert Level. This is a valid and fair method of calculation that always produce a higher number than the numerical average of the data used in the calculation. For Sulfates, it simply means that if the concentration of Sulfates in a future sample is higher that the Alert level, this is proof that the sample result is not a random error to be ignored, but evidence that a significant increase in Sulfate concentration has occurred, and any corrective measure required in the permit must be implemented. The problem in the draft APP is not the method applied, but the choice of well CW8 to apply the method.

Establishing the 650 mg/L Alert Level at CW-8 is disturbing for the following reasons.

Well CW8 is in the sulfate plume, and historically has demonstrated the highest Sulfate and TDS concentrations among the four Community Water production wells.

Available Sulfate data for CW-8 suggest that the Sulfate concentrations may have peaked at a concentration of less than 600 mg/L, and also may be declining. In other words, it is possible that the 650 mg/L Alert Level may never be reached.

This Alert Level does not protect the Arsenic Treatment facilities being installed by Community Water at Wells 6 and 9.

CONCLUSION: Well CW8 is not an appropriate Point of Compliance. It appears that there is insufficient data to select a meaningful Point of Compliance and Alert Level that is protective of Community Water’s regulatory requirement to meet the new Arsenic Standard at Wells 6 and 9.

For this reason, and our belief that there is insufficient data on metals in the plume, we are asking that the following requirement be added to the draft APP:

“Beginning in the first calendar month after the effective date of APP No. 101679, and continuing for at least 12 months, ambient water quality monitoring shall be conducted at wells MH-11, MH-12, MH-25A, MH-26A, CW-6, CW-7, CW-8, CW-9, the 4 PDSI wells in the Esperanza Wellfield, and the inactive New Pueblo Water Company wells. Samples collected are to be analyzed for the parameters listed in Table 4.2.3 of the draft APP plus the metals Aluminum, Antimony, Arsenic, Beryllium, Cadmium, Calcium, Chromium, Cobalt, Copper, Lead, Magnesium, Manganese, Molybdenum, Nickel, Selenium and Thallium*. Once the twelve-month sampling activity is completed, the permittee may request changes in the sampling schedule, number of sampling points, and changes in the parameter list for these ‘non-hazardous’ monitoring points.”

* Table 4.2.3 of the draft APP lists Barium as the only metal in the parameter list.

Monthly sampling should provide the needed information on Metals concentrations in a timely fashion. The 12-month sampling period will also provide information on seasonal variations. The sampling of the wells close to the Tailing Impoundment, the four Community Water Wells, the four wells in the Esperanza Wellfield, and the New Pueblo wells should provide the needed identification and quantification of the metals present, contribute to better understanding of the “plume” itself, and provide a basis for selecting meaningful Points of Compliance that are protective to the Arsenic Treatment facilities at Community Water wells 6 and 9.

Section 3 of the Draft APP for PDSI does require that PDSI “define the discharge impact area using the sulfate plume characterization study”. This requirement is to be completed within twelve months of the effective date of the final APP. Because of the importance of this topic to the citizens and the water companies of Green Valley, we request that the following language be added:

“Beginning at the effective date of the final APP, and continuing until the final report is issued to ADEQ, PDSI should prepare and publish quarterly informational reports on the progress, preliminary findings, and potential implications for the aquifer of this sulfate plume characterization study. Copies of these quarterly reports should be transmitted to the three water companies serving Green Valley, and to the Green Valley Community Coordinating Council.”

One Final Point

Throughout this process of review and comment, I found it impossible to obtain what I consider to be public information. This applies to everything ranging from water sample data that has been reported to ADEQ, to documents referenced in the draft APP. I sincerely hope that the final APP will include provisions to see that this is no longer the case. Whether this becomes a requirement for the permittee, or some other mechanism specified by ADEQ is left to ADEQ’s judgment. However, the final permit should require this flow of information, and the recipient of that information should be the Green Valley Community Coordinating Council.

Background Information

And

Supporting Documentation

The Setting

The draft APP states that the PDSI mine is located 6 miles northwest of Green Valley. There may be some mining operations that far away, and in that direction from some part of Green Valley. The following information gives distances from the Tailing Impoundment to points of interest in Green Valley

The Southeast Corner of the PDSI Tailing Impoundment is about 0.5 miles west of Green Valleys western Planning Boundary,

The Northeast corner of the PDSI Tailing Impoundment is about 1.1 miles west of Green Valley’s western Planning Boundary,

Green Valley Water District’s production wells are 1.6 miles east of the east wall of the PDSI Tailing Impoundment,

Community Water’s well 8 (no longer active) is about 1.6 miles east of the northeast corner of the PDSI Tailing Impoundment,

Community Water’s well 6 (an active well) is about 0.6 miles EENE of well 8,

Community Water’s well 7 (no longer active) is about 2.2 miles NE of the northeast corner of the PDSI Tailing Impoundment, and

Community Water’s well 9 (an active well) is about 0.8 miles NE of well 7.

The Community of Green Valley

The unincorporated community of Green Valley is special and distinctive. Because it is a retirement community, Green Valley is very different in demographics than the “average” for the United States, as the following table developed from US Census Bureau, Census 2000 data illustrates.

Population Statistic	Green Valley (CDP)	United States
Median Age, years	72.2	35.3
Percent, Under Age 5	0.4	6.8
Percent, Age 5 to 19 years	1.4	21.8
Percent, Age 55 and Older	90.2	21.0
Percent, Age 65 and Older	73.3	12.4
Percent, Age 75 and Older	39.2	5.9
Percent, Age 65 to 84 years	65.3	10.9

Also, Green Valley has residents who retired from a wide range of backgrounds; moved here from each of the 50 states, and some from other countries. This diversity provides a wide-ranging variety of experiences and cultures, which, in turn, can produce a wide range of opinion on any issue facing the Community at any given time.

Also, if it is true that as we age we become more sensitive to factors that influence our health, we may have a much larger “sensitive population” than the US average.

The Community Concerns Over Sulfates in our Drinking Water

Over the past 10 years, some residents the northern end of Green Valley, served by Community Water Company, have experienced increasing concentrations of Sulfates and Total Dissolved Solids (TDS) in their tap water. We believe that these contaminants are associated with a “Sulfate Plume” entering the Upper Santa Cruz Basin aquifer from the Tailing Impoundment at the Phelps Dodge Sierrita Incorporated (PDSI) Copper Mine located west of Green Valley. The Sulfate Plume has impacted two of Community Water’s four production wells. Because of the complex nature of Community Water’s distribution system, this means that some but not all households in Community Water’s system have experienced the “high” sulfates concentrations in their tap water. To further complicate the situation, some households have under-sink reverse osmosis systems to provide drinking water, while other households purchase treated water for drinking.

To date, the other two water companies serving parts of Green Valley (Green Valley Water District, and Farmers Water Company) have not experienced high levels of Sulfates and TDS in their production wells.

Therefore, the problem is not community-wide, and opinions within the community tend to be based on personal experience as well as general concerns.

Actions Taken

To their credit, PDSI has worked with Community Water Company to provide a solution to the Sulfate problem. As a “temporary solution”, Community Water is accepting water from three PDSI wells located in their Esperanza Wellfield. This has allowed Community Water to discontinue use of wells 7 and 8, the two wells impacted by the “sulfate plume.” Therefore, Community Waters customers are no longer receiving water containing high sulfates and TDS.

PDSI and Community Water are continuing to work together to come up with a “permanent solution”. This “permanent solution” appears to be based on a strategy that can be characterized as “running from the plume”. Community Water is installing a new well in the Southeast corner of their service area (about as far as they can go in that direction). This well, designated as Well 10 is a “replacement” for Well 8. Community Water is studying the northeast corner of their service area for a suitable location for another new well (presumably, Well 11), which would be the replacement for Well 7. The need for Arsenic treatment is an open question for these two wells.

Supplemental Data & Commentary: Two Figures and Two Maps

The Figures

Figures 1 and 2 (attached) are crude plots of Sulfate and TDS for Community Water Wells 7 and 8. These plots were developed as simple tools to document and track the Sulfate and TDS concentrations in these two wells. In both Figures, Sulfate data is shown in green ink, and TDS data in black ink. These figures are included in support of statements made in this document.

The Maps

A copy of a map “Green Valley Wells 2003” provided by Pima County Department of Environmental Quality has been adapted for use in this analysis. This map may be “dated”, and may not completely and correctly show locations for all drinking water wells in the Green Valley area. However it is believed to be good enough for providing some information for this discussion. This map has been marked to indicate Community Water Wells 6, 7, 8, and 9.

This map also shows well locations for other water companies. The wells shown for New Pueblo Water Company are no longer active, and this area is now part of Community Water’s service area. Also, the Farmers Water well that provides water to the portion of Green Valley east of Interstate 19 and south of Rebecca is not shown.

A Second map “Certificated Area”, and dated April 2003, was provided by Community Water Company of Green Valley. This map shows wells 7 and 8 as active wells. That was correct in 2003, but both are now inactive.

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