This PHA considers use of water resources as a sole source of drinking water over a lifetime. However, the evaluations and therefore the conclusions discussed in this section do not yet include any contribution from other sources of contamination that the residents of Vieques may encounter. As other sources are investigated, any additional exposures will be evaluated in conjunction with these findings to determine cumulative effects.

ATSDR has categorized this site as having no apparent public health hazard. In evaluating exposures to contaminants found in Well 3-7, ATSDR concluded this well posed a public health hazard; however, PRDOH issued an advisory for this well and notified the residents not to use it to supply drinking water. Because no data are currently available, ATSDR concludes that rainfall collection systems pose an indeterminate public health hazard. (Definitions of public health categories are included in the glossary in Appendix A.) Conclusions regarding the drinking water sources evaluated by ATSDR are as follows:

The majority of the residents receive their drinking water from the mainland of Puerto Rico. Three different agencies tested the drinking water within the public water supply system. After an evaluation of the results of these tests, ATSDR concludes that the public drinking water supply is not being impacted by the bombing range activities and is safe to drink.
Groundwater cannot travel from the LIA across the island to residential areas of the island. Therefore, groundwater from the LIA is not impacting groundwater in the residential area of Vieques.
Some residents may supplement their drinking water supply by using water from groundwater wells. EPA and PRDOH sampled various groundwater wells and ATSDR evaluated the results. The water from the three Sun Bay wells, the four B wells, and Well 2-3 is safe to drink whenever the public water supply is interrupted. However, residents who are on a sodium-restricted diet should be cautious when drinking water from these wells.
One private well (Well 3-7) showed high levels of nitrates plus nitrites. The water from Well 3-7 is not safe to drink, especially for children and pregnant women. In October 1999, PRDOH issued an advisory and personally informed residents that water from this well is not safe for consumption. ATSDR agrees that residents, especially children and pregnant women, should not drink the water from Well 3-7. Because of the hydrogeology of the island and analysis of other groundwater wells in the area, ATSDR does not believe that the high level of nitrates plus nitrites in groundwater is a consequence of the bombing range activities; rather, it is probably a result of agricultural activities or septic systems in the area.
The location, use, and extent of contamination in rainfall collection systems are not available. Therefore, the potential impact from drinking water from rainfall collection systems cannot be evaluated at this time. ATSDR's evaluation of the air pathway will provide additional insight into this potential exposure route.
Very low levels of RDX, tetryl, ammonia, and nitrate plus nitrite may have been present in drinking water samples taken by the Navy in 1978. However, ATSDR has doubts about the validity of the data because of the small number and description of the samples. The authors of the report noted that "a completely positive identification was not possible due to the extremely low concentrations found" (Hoffsommer and Glover 1978). The levels of nitrate plus nitrite are consistent with groundwater on the island and are not conclusive evidence of explosive contamination. In addition, more recent analyses of drinking water samples did not detect any explosive related contamination. The concentrations of explosive compounds reported in drinking water in the past were well below levels considered harmful to human health and past exposure to these compounds does not pose a public health hazard.
There is no evidence that residents of Vieques have been exposed to additional levels of radiation as a result of the February 1999 use of depleted uranium (DU) rounds in the LIA. Based on samples taken from across Vieques, the NRC concluded that there was no spread of DU to areas outside the LIA. The levels of radiation detected in soil, vegetation, and water by the NRC investigators are consistent with normal radiation background levels and do not represent a public health hazard.

VIII. PUBLIC HEALTH ACTION PLAN

The Public Health Action Plan for Vieques contains a description of actions taken and those to be taken by ATSDR, the Navy, EPA, PREQB, and PRDOH. The purpose of the Public Health Action Plan is to ensure that this PHA not only identifies public health hazards, but also provides a plan of action to mitigate and prevent adverse human health effects resulting from exposure to hazardous substances in the environment. The public health actions that are completed, planned, or recommended are as follows:

Actions Completed:

Drinking water and groundwater sampling was carried out by various agencies, including EPA, PRDOH, PREQB, USGS, and the Navy.
In August 1999, ATSDR conducted an initial site visit to Vieques to meet with the petitioner, tour the island and bombing range, and gather available environmental data. As a result of this site visit, ATSDR accepted the resident's petition and initiated the PHA process.
In September 2000, ATSDR met with various agencies including PRDOH, PREQB, EPA, USGS, and the Navy to gather data and to discuss the scope and nature of ATSDR investigations. ATSDR also met with the petitioner to tour various sites on Vieques and provide an update on ATSDR efforts.
In June and October 2000, ATSDR discussed with local health care providers their concerns about public health and provided training about how to medically assess environmental exposures. During these visits ATSDR met with numerous residents of the island to discuss health concerns.
In September 2001, ATSDR conducted additional community involvement activities to inform participants of the scope of ATSDR investigations and seek additional community input. Continuing education-public health training was held for the nurses of Vieques and environmental health instruction was given to area parents and high school students.
ATSDR held a public availability session on March 14, 2001 to be available to meet individually with community members about the findings of the evaluation of drinking water on Vieques.

Actions Planned:

ATSDR will continue to identify and analyze potential and completed pathways as data become available and will impart the findings to the residents of Vieques in additional focused PHAs.

Recommendations for Further Action:

Because the levels of nitrate and nitrite in Well 3-7 is a public health hazard and because there may be other similar shallow domestic drinking water wells in use that have not been identified, ATSDR recommends that when such wells are identified that PRDOH or PREQB sample those wells to ensure that the well water is safe to drink.
It is known that some rainfall collection systems are installed on Vieques. The available information indicates that most of these systems are used to provide an emergency water supply. However, some rainfall collection systems may be used for a more continuous drinking water supply. ATSDR recommends that PRDOH or PREQB identify examples of such collection systems and perform sampling to evaluate if these systems deliver tap water that is safe to drink. If the storage tanks associated with these collection systems contain bottom sediments, it is recommended that those sediments be sampled to provide an indication of potential past water quality.
ATSDR recommends that PRDOH or PREQB, in coordination with Compania de Aguas, take the necessary steps to ensure that backup water supply systems are available during emergency situations.

Other Public Health Assessment Activities

Completed or Ongoing Actions:

ATSDR will continue to identify and analyze potential pathways as data become available and will impart the findings to the residents of Vieques in additional focused PHAs. Efforts are ongoing to assess potential pathways of contaminant transport through the air, soil, and food chain. Reports on these evaluations will be made available for public comment when they are completed.
ATSDR requested that the Navy sample soil on the LIA for use in our assessment of the air and soil pathways. This sampling has been completed and was received by ATSDR in early January 2001. Evaluation of those data is underway.
ATSDR is continuing to meet with various community members and organizations to gather concerns and exchange information. This effort will continue throughout the PHA process.
ATSDR has and will continue to meet with local health care providers to discuss health concerns for the community and to provide educational materials for addressing the community's health needs.
ATSDR will review cancer registry information and data gathered by the PRDOH. The information will be evaluated as it relates to potential pathways of environmental exposure and general health status of the communities.
PRDOH is working on Vieques to gather information about recent cancer cases on the island. The information gathered will be added to the current cancer registry information.

PREPARERS OF REPORT

W. Mark Weber, Ph.D.
Geologist
Federal Facilities Assessment Branch
Division of Health Assessment and Consultation

Gary Campbell, Ph.D.
Environmental Health Scientist, Section Chief
Federal Facilities Assessment Branch
Division of Health Assessment and Consultation

Michelle Arbogast, M.S.
Environmental Scientist
Eastern Research Group

Emilio Gonzalez, P.E.
Environmental Health Scientist
Federal Facilities Assessment Branch
Division of Health Assessment and Consultation

Danielle DeVoney, Ph.D.
Toxicologist
Federal Facilities Assessment Branch
Division of Health Assessment and Consultation

REFERENCES

Agency for Toxic Substances and Disease Registry (ATSDR). 1992. Toxicological profile for boron. Atlanta: U.S. Department of Health and Human Services; July 1992.

Agency for Toxic Substances and Disease Registry (ATSDR). 1997. Toxicological profile for manganese. Atlanta: U.S. Department of Health and Human Services; September 1997.

Austin Nutritional Research (ANR). 2000. Reference guide for minerals. Available from URL: http://www.realtime.net/anr/minerals.html.

Baker Environmental, Inc. (Baker). 1999. Vieques groundwater sampling information. November 15, 1999.

Bermudez W. 1998. Brief history of Vieques. Available from URL: http://www.vieques-island.com/hisindx.html.

CH2MHILL and Baker Environmental, Inc. (Baker). 1999. Results of the hydrogeologic investigation: Vieques Island, Puerto Rico; November 4, 1999.

Cherry GS and Ramos J. 1995. Water wells on Isla de Vieques, Puerto Rico. U.S. Geological Survey, Open-file report 95-368. San Juan, Puerto Rico: 1995.

Department of the Navy (Navy), Atlantic Division. 1990. Water quality study at the U.S. Atlantic Fleet Weapons Training Facility, Vieques Island, Puerto Rico: September 1990.

Department of the Navy (Navy). 2000. Environmental assessment for the transfer of the Naval Ammunition Support Detachment property, Vieques, Puerto Rico: November 2000.

Environmental Protection Agency (EPA). 1984. National secondary drinking water regulations: Total dissolved solids. Washington, DC: June 1984.

Environmental Protection Agency (EPA). 1988. Integrated Risk Information System (IRIS): Manganese. September 16, 1988. Available from URL: http://www.epa.gov/iriswebp/iris/subst/0373.htm.

United States Environmental Protection Agency (EPA). 1992. Drinking Water Health Advisory: Munitions. eds. Roberts WC and Hartley WR . Boca Raton, FL: Lewis Publishers. p. 181-199.

Environmental Protection Agency (EPA). 1995. National primary drinking water regulations: Nitrates and nitrites. Washington, DC: October 1995.

Environmental Protection Agency (EPA), Caribbean Environmental Protection Division. 1999a. Interview with Engineer Rafael Cruz Perez, P.E. on the Contamination of Drinking Water by Explosives in Vieques, Puerto Rico. San Juan, Puerto Rico: August 4, 1999.

Environmental Protection Agency (EPA), Region 2 Division of Environmental Assessment, Monitoring and Assessment Branch. 1999b. Potable water storage tank and well sampling report: Vieques, Puerto Rico. Edison, NJ: November 5, 1999.

Environmental Protection Agency (EPA), Region 2. 1999c. Data Validation Results for Vieques, Puerto Rico. December 1, 1999.

Environmental Protection Agency (EPA), Region 2 Division of Environmental Assessment, Monitoring and Assessment Branch. 2000. Sampling of the Rio Blanco filter plant & Vieques public water supply tanks. Edison, NJ: March 21, 2000.

Feron VJ, Jonker D, Groten JP, Horbach GJMJ, Cassee FR, Schoen ED, Opdam JJG. 1993. Combination technology: From challenge to reality. Toxicology Tribune 14: 1-3.

Hoffsommer JC and Rosen JM. 1972. Analysis of Explosives in Sea Water. White Oak, Silver Spring, MD: 1972.

Hoffsommer JC and Glover DJ. 1978. Explosives analyses of water and soil samples taken on Vieques Island, Puerto Rico. White Oak, Silver Spring, MD: May 11-16 1978.

IT Corporation (IT). 2000. Atlantic Division Naval Facilities Engineering Command, Air dispersion modeling and related analyses for Inner Range operations, Vieques, Puerto Rico. Knoxville, TN: February 2000.

Lai MG. 1978. Explosion products content of water and soil samples taken on Vieques Island, Puerto Rico. White Oak Laboratory, Silver Spring, MD: May 11-16 1978.

Navy - see Department of Navy.

National Climatic Data Center (NCDC). 1994. Annual Climatological Summary for Vieques Island, Puerto Rico: May 1985 through January 1994.

Nuclear Regulatory Commission (NRC). 2000a. Letter from Luis A. Reyes to Carmen Feliciano Melecio concerning presence of depleted uranium on Vieques. Atlanta, GA: February 1, 2000.

Nuclear Regulatory Commission (NRC). 2000b. Environmental Survey Inspection Report, Vieques Island, Puerto Rico: September 28, 2000.

Puerto Rico Department of Health (PRDOH). 1995a. Data sheets concerning contamination at three Sun Bay wells on Isla de Vieques. San Juan, Puerto Rico: May 1995.

Puerto Rico Department of Health (PRDOH). 1995b. Data sheets concerning contamination at four B wells on Isla de Vieques. San Juan, Puerto Rico: May 1995.

Puerto Rico Department of Health (PRDOH). 1998. Sanitary Conditions Survey. Fajardo, Puerto Rico: July 21-24 1998.

Puerto Rico Department of Health (PRDOH). 1999. Investigation of the potable water in Vieques. San Juan, Puerto Rico: August 11, 1999.

Seed J, Brown R, Olin P, Stephen S, and Foran JA. 1995. Chemical Mixtures: Current Risk Assessment Methodologies and Future Directions. Regulatory Toxicology and Pharmacology 22:76-94.

Torres-Gonzalez S. 1989. Reconnaissance of the ground-water resources of Vieques Island, Puerto Rico. U.S. Geological Survey, Report 86-4100. San Juan, Puerto Rico: 1989.

Torres R, Tirado G, Roman A, Ramirez R, Colon H, Araujo A, Pais F, Maciniak W, Nobrega J, Bordalo e Sa A, Lopo Tuna JMC, Alves-Pereira M, Castelo Branco NAA. Vibroacoustic Disease Induced by Long-Term Exposure to Sonic Booms. Draft manuscript.

U.S. Bureau of the Census. 2000. Census of population and housing: Summary Tape File. U.S. Department of Commerce. 2000.

U.S. Department of Agriculture and U.S. Department of Health and Human Services (USDA and USDHHS). 2000. Dietary guidelines for Americans. Available from URL: http://www.health.gov/dietaryguidelines/dga2000/dietGD.pdf. Washington, DC: 2000.

U.S. Geological Survey (USGS). 1997. Letter from Rafael Rodriguez to Winston Martinez concerning sampling of Navy wells in the NASD. March 3, 1997.

U.S. Geological Survey (USGS). 2000. African Dust Causes Widespread Environmental Distress. April 2000. Available from URL: http://coastal.er.usgs.gov/african-dust/events.html.

Young, GA. 1978. Environmental dispersion of the products of explosions of conventional ordnance at Vieques Island, Naval Surface Weapons Center: August 28, 1978.

TABLES

Table 1. Summary of Pathways Evaluated in this Public Health Assessment

Pathway Name	Exposure Pathway Elements						Comments
Pathway Name	Potential Source of Contamination	Environmental Media	Point of Exposure	Route of Exposure	Exposed Population	Time of Exposure	Comments
*Potential Exposure Pathways*
Drinking water from the public water supply system	None	None The pipeline water supply in Vieques storage tanks is not contaminated	None	None	None	None	The source of the public water is the Rio Blanco, located on the main island of Puerto Rico.There is no reasonable pathway that would connect bombing activities at the LIA with the Rio Blanco.
Drinking water from groundwater wells in the residential area	Bombing at the LIA and open burning/open detonation activities	Groundwater	None Groundwater under the LIA cannot reach drinking water wells.	None	None	None	There is no hydrogeological connection between groundwater at the LIA and the residential area of the island.
		Air Soil Groundwater	None Public and private drinking water wells show no contaminants at levels that would cause illness.	None	None	None	Recent sampling did not detect explosives or explosive residues in the groundwater.
Drinking water from rainwater collection systems	Bombing at the LIA and open burning/open detonation activities	Air deposition in rainfall collection systems	Household use of water from rainfall collection systems	Dermal Contact Ingestion Inhalation	Residents of Vieques using rainfall collection systems	Past, current, and future	Additional information is needed on use of past and current rainfall collection systems. Potential of air transport and deposition of contaminants into collection systems is being assessed by evaluating the potential air pathway. ATSDR will address the air pathway and the potential for deposition into the rainfall collection systems in a future focused public health assessment.
Past drinking water sources	Explosives potentially from military activities	Groundwater or Storage tanks	Drinking water	Dermal Contact Ingestion Inhalation	Residents of Vieques	Past	Although levels of explosives were reported in sampling from 1978, their presence was not conclusive and the data are uncertain. However, even if present at levels reported, these contaminants were well below levels considered harmful to human health.
*Exposure Pathway of Health Concern*
Drinking water from Well 3-7	Agricultural contamination	Groundwater supplying drinking water well.	Household use of water from well.	Ingestion Inhalation	Users of well.	Past, current?, and future?	Nitrates plus nitrites potentially from agricultural sources have contaminated the well. The PRDOH has advised residents of health concerns related to use of the well.

Table 2. Chemicals Detected in the Public Water Supply

Chemical	Chemical Concentration Range (ppb)	Frequency of Detections	Frequency above Standards	Drinking Water Standards (ppb)
Metals
Aluminum ^a	77	1/12	0	50-200*
Barium ^b	16	1/12	0	2,000†
Boron	13-22	9/11	NA	NA
Copper	13-45	2/11	0	1,300§
Iron	53-240	5/11	0	300*
Magnesium	3,700	1/1	NA	NA
Manganese	2-20	12/12	0	50*
Potassium	1,300	1/1	NA	NA
Sodium	8,800-9,900	12/12	NA	NA
Strontium	47	1/1	NA	NA
Zinc	9-36	5/12	0	5,000*
Volatile Organic Compounds
Chlorodibromomethane	1.0-2.8	12/12	0	80‡
Chloroform	44-74	12/12	0	80‡
Dichlorobromomethane	10-14	12/12	0	80‡
4-Methyl-2-pentanone	2.6-3.3	2/11	NA	NA
Toluene	1.1	1/12	0	1,000†
Total Trihalomethanes	56-88	11/11	0	100†
Inorganics
Ammonia	19	1/1	NA	NA
Chloride	20,100-25,000	12/12	0	250,000*
Fluoride	30-70	2/12	0	4,000†
Nitrate	250	1/1	0	10,000†
Nitrate plus Nitrite	50-140	6/10	0	10,000†
Sulfate	5,050-8,100	11/11	0	250,000*
Total Dissolved Solids	87,000-110,000	10/10	0	500,000*

Di(2-ethylhexyl)phthalate was reported by the lab, but quality assurance/quality control data indicted it was an artifact of the sampling process and not considered representative of the water quality.

Reference: Baker 1999; EPA 1999b; PRDOH 1999

Abbreviations:
MCL = Maximum Contaminant Level (EPA)
MCLG = Maximum Contaminant Level Goal for drinking water (EPA)
NA = Not Available
ppb = parts per billion
SMCL = Secondary Maximum Contaminant Level (EPA)

† MCL
‡ Propsed MCL
* SMCL
§ MCLG
^a EPA and PRDOH sampled with detection limits higher than the concentration detected by the Navy's contractor.
^b PRDOH sampled with a detection limit higher than the concentration detected by the Navy's contractor.

Table 3. Chemicals Detected in Groundwater Wells in the Esperanza Valley Aquifer

Chemical	Sun Bay Wells			B Wells			Navy Well 14			Drinking Water Standards (ppb)
Chemical	Range (ppb)	Frequency of Detections	Frequency above Standards	Range (ppb)	Frequency of Detections	Frequency above Standards	Range (ppb)	Frequency of Detections	Frequency above Standards	Drinking Water Standards (ppb)
Metals
Barium	ND	0/6	0	ND	0/4	0	210	1/1	0	2,000†
Beryllium	ND	0/6	0	ND	0/4	0	0.45	1/1	0	4†
Boron	203-226	3/3	NA	NS	-	-	NS	-	-	NA
Calcium	NS	-	-	NS	-	-	85,000	1/1	NA	NA
Copper	ND	0/6	0	ND	0/4	0	27	1/1	0	1,300§
Iron	1,060-2,150	3/6	3	ND	0/4	0	ND	0/1	0	300*
Lead	ND	0/6	0	ND	0/4	0	1.9	1/1	0	15†
Manganese	60-528	5/6	5	ND	0/4	0	1	1/1	0	50*
Molybdenum	ND	0/3	0	NS	-	-	ND	0/1	0	NA
Sodium	103,000- 120,000	6/6	NA	158,000- 195,000	4/4	NA	140,000	1/1	NA	NA
Vanadium	NS	-	-	NS	-	-	7.5	1/1	NA	NA
Zinc	5-24	3/6^a	0	ND	0/4	0	31	1/1	0	5,000*
Volatile Organic Compounds
Chloroform	ND	0/9	0	1.3-1.6	2/8	0	1.6	1/1	0	80‡
Total Trihalomethanes	ND	0/6	0	2.9	1/4	0	NS	-	-	100†
Semi-volatile Organic Compounds
Di-n-butylphthalate	ND	0/6	0	ND	0/4	0	0.37	1/1	NA	NA
Inorganics
Chloride	78,000- 102,000	6/6	0	64,000- 113,000	4/4	0	260,000	1/1	1	250,000*
Fluoride	500	1/4	0	570-670	4/4	0	150	1/1	0	4,000†
Ortho-Phosphate	NS	-	-	NS	-	-	720	1/1	NA	NA
Sulfate	31,000- 39,700	6/6	0	48,000- 77,000	4/4	0	47,000	1/1	0	250,000*
Nitrate	1,600-2,100	3/3	0	540-1,700	5/5	0	11,000	1/1	1	10,000†
Nitrite	ND	0/6	0	ND	0/4	0	50	1/1	0	1,000†
Nitrate plus Nitrite	260-1,860	3/3	0	NS	-	-	NS	-	-	10,000†
Total Dissolved Solids	90,500- 1,670,000	6/6	3	534,000- 658,000	4/4	4	790,000	1/1	1	500,000*

References: EPA 1999b, PRDOH 1995a,b; Baker 1999

Abbreviations:
MCL = Maximum Contaminant Level (EPA)
SMCL= Secondary Maximum Contaminant Level (EPA)
NA = Not Available
ND = Not Detected
NS = Not Sampled
ppb = parts per billion

† MCL
‡ Propsed MCL
* SMCL
§ MCLG
^a Three of the six samples were below detection limits of 60 ppb.

Table 4. Chemicals Detected in Groundwater Wells in the Resolucion Aquifer

Chemical	Former Navy Wells in NASD			Drinking Water Standards (ppb)
Chemical	Range (ppb)	Frequency of Detections^a	Frequency above Standards	Drinking Water Standards (ppb)
Metals
Barium	130	1/1	0	2,000†
Beryllium	0.79	1/1	0	4†
Calcium	14,000-71,000	6/6	NA	NA
Chromium	1.8	1/1	0	100†
Cobalt	2.4	1/1	NA	NA
Iron	800-5,000	6/6	6	300*
Lead	1.1	1/1	0	15 †
Magnesium	12,000-45,000	5/5	NA	NA
Manganese	32-540	6/6	5	50*
Nickel	2	1/1	0	100†
Sodium	160,000-168,000	6/6	NA	NA
Vanadium	3.3	1/1	NA	NA
Zinc	3.7-30	3/6	0	5,000*
Volatile Organic Compounds
Benzene^a	21	1/1	1	5†
Chloroform	0.74-6.2	3/4	0	80‡
Toluene^b	0.22	1/1	0	1,000†
Semi-volatile Organic Compounds
Di-n-butylphthalate	0.56	1/1	NA	NA
Siloxane	1.1-1.9	2/3	NA	NA
Sanitary Analytes
Chloride	76,000-380,000	6/6	1	250,000*
Fluoride	200	1/6	0	4,000†
Ortho-Phosphate	41	1/1	NA	NA
Sulfate	15,000-38,000	6/6	0	250,000*
Total Dissolved Solids	790,000	1/1	1	500,000*
Nitrate	55-1,700	6/6	0	10,000†
Nitrite	19	1/1	0	1,000†
Other
Gross Beta	5.97 pCi/L	1/1	0	15 pCi/L†

Reference: Baker 1999; USGS 1997

Abbreviations:
MCL = Maximum Contaminant Level (EPA)
MCLG = Maximum Contaminant Level Goal for drinking water (EPA)
NA = Not Available
ND = Not Detected
pCi/L = picocurries per liter
ppb = parts per billion
SMCL = Secondary Maximum Contaminant Level (EPA)

† MCL
‡ Propsed MCL
* SMCL
^a One of the five wells was sampled by both the Navy's contractor and USGS; the remaining four were only sampled by USGS.
^b The chemical was not detected in the duplicate of this sample.

Table 5. Chemicals Detected in Other Groundwater Resources

Chemical	Well 3-7			Well 2-3			Drinking Water Standards (ppb)
Chemical	Range (ppb)	Frequency of Detections	Frequency above Standards	Range (ppb)	Frequency of Detections	Frequency above Standards	Drinking Water Standards (ppb)
Metals
Barium	267	1/1	0	ND	0/1	0	2,000†
Boron	280	1/1	NA	264	1/1	NA	NA
Manganese	27	1/1	0	25	1/1	0	50*
Molybdenum	ND	0/1	0	0.05	1/1	NA	NA
Sodium	229,000	1/1	NA	172,000	1/1	NA	NA
Zinc	6	1/1	0	14	1/1	0	5,000*
Inorganics
Chloride	242,000	1/1	0	202,000	1/1	0	250,000*
Sulfate	62,400	1/1	0	63,000	1/1	0	250,000*
Nitrate plus Nitrite	1,700-12,600	2/2	1	500-1,330	2/2	0	10,000†
Total Dissolved Solids	1,330,000	1/1	1	1,220,000	1/1	1	500,000*

References: EPA 1999b; EPA 2000

Abbreviations:
MCL = Maximum Contaminant Level (EPA)
NA = Not Available
ND = Not Detected
NS = Not Sampled
ppb = parts per billion
SMCL = Secondary Maximum Contaminant Level (EPA)

† MCL
‡ Propsed MCL
* SMCL