Blanchard, Paul J.—Precipitation; Ground-Water Age; Ground-Water Nitrate Concentrations, 1995-2002; and Ground-Water Levels, 2002-03 

in Eastern Bernalillo County, New Mexico—Scientific Investigations Report 2004-5189
Precipitation; Ground-Water Age; 

Ground-Water Nitrate Concentrations, 

1995-2002; and Ground-Water Levels, 

2002-03 in Eastern Bernalillo County, 

New Mexico 

By Paul J. Blanchard 

Prepared in cooperation with Bernalillo County 

Scientific Investigations Report 2004-5189 

U.S. Department of the Interior

U.S. Geological Survey
U.S. Department of the Interior 

Gale A. Norton, Secretary 

U.S. Geological Survey

Charles G. Groat, Director 

U.S. Geological Survey, Reston, Virginia: 2004 

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 iii 

Contents 

Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1


Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1


Purpose and Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1


Description of the Study Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2


Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2


Precipitation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2


Precipitation at National Oceanic and Atmospheric Administration Sites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2


Snowfall at National Oceanic and Atmospheric Administration Sites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6


Precipitation at U.S. Geological Survey Sites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6


Ground-Water Age . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17


Dissolved Nitrate Concentrations, 1995-2002 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17


Ground-Water-Level Changes, 2002-03 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19


Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23


References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24


Supplemental Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25


Figures 

1-3. Maps showing— 

1.	 Location of study area and data-collection sites, eastern Bernalillo County, New Mexico . . . . .3


2.	 Geologic terranes in eastern Bernalillo County, New Mexico . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4


3.	 Approximate ground-water divide and general direction of ground-water flow in 


eastern Bernalillo County, New Mexico. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5


4-8. Graphs showing—


4.	 Average monthly precipitation at Sandia Crest, Sandia Park, and Sandia Ranger Station, 


periods of record . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9


5.	 Average monthly snowfall at Sandia Crest, Sandia Park, and Sandia Ranger Station, 


periods of record . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12


6.	 Average monthly precipitation at site 8, Sandia Crest, 1953-79, and monthly precipitation 


at site 1, Sandia Mountains high altitude, 2001-03 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13


7.	 Average monthly precipitation at site 9, Sandia Park, 1939-2001, and monthly precipitation 


at site 3, Sandia Mountains low altitude, 2001-03 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14


8.	 Average monthly precipitation at site 10, Sandia Ranger Station, 1933-74, and monthly 


precipitation at site 7, Tijeras, New Mexico, 2001-03. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15


9-11. Maps showing—


9.	 Estimated age of ground water in selected monitoring wells and spring as determined 


by concentrations of chlorofluorocarbons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18


10.	 Change in dissolved nitrate concentrations in selected monitoring wells, 1995-98 to 


2001-02. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20


11.	 Change in ground-water levels in selected monitoring wells, 2002-03. . . . . . . . . . . . . . . . . . . . . . . . 22

iv 

Tables 

1.	 Precipitation sites in the eastern Bernalillo County study area. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6 

2.	 Monthly and annual precipitation, in inches, at National Oceanic and Atmospheric 

Administration precipitation stations, periods of record . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7 

3.	 Monthly and annual precipitation, in inches, at National Oceanic and Atmospheric 

Administration precipitation stations, 1954-74 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8 

4.	 Monthly and annual snowfall, in inches, at National Oceanic and Atmospheric 

Administration precipitation stations, periods of record . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 

5.	 Monthly and annual snowfall, in inches, at National Oceanic and Atmospheric 

Administration precipitation stations, 1954-74 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 

6.	 Comparison of average monthly and annual precipitation at National Oceanic and 

Atmospheric Administration precipitation sites and monthly and annual precipitation 

at U.S. Geological Survey and volunteer precipitation sites. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 

7.	 Estimated ground-water age determined by concentrations of chlorofluorocarbons . . . . . . . . . . . . . . 19 

8.	 Nitrate concentrations in monitoring wells, 1995-2002, and change, 2001-02, from most 

recent 1995-98 concentration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 

9.	 Ground-water-level changes in selected monitoring wells, 2002-03 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 

10.	 Monthly and annual precipitation at U.S. Geological Survey and volunteer precipitation sites, 

2001-03. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 

11.	 Precipitation at Sandia Crest, in inches, 1953-79. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 

12.	 Precipitation at Sandia Park, in inches, 1939-2001 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 

13.	 Precipitation at the Sandia Ranger Station, in inches, 1933-74 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 

14.	 Snowfall at Sandia Crest, in inches, 1953-79. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 

15.	 Snowfall at Sandia Park, in inches, 1939-2001 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 

16.	 Snowfall at the Sandia Ranger Station, in inches, 1933-74 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 

Conversion Factors and Vertical Datum 

Multiply By To obtain 

Length 

inch (in.) 2.54 centimeter (cm) 

foot (ft) 0.3048 meter (m) 

mile (mi) 1.609 kilometer (km) 

Area 

square mile (mi2) 2.590 square kilometer (km2) 

Vertical coordinate information is referenced to the North American Vertical Datum of 1988 

(NAVD 88). 

Altitude, as used in this report, refers to distance above or below the National Geodetic Vertical 

Datum of 1929 (NGVD 29). 

Concentrations of chemical constituents in water are given in milligrams per liter (mg/L). 
Precipitation; Ground-Water Age; Ground-Water Nitrate 

Concentrations, 1995-2002; and Ground-Water Levels, 

2002-03 in Eastern Bernalillo County, New Mexico 

By Paul J. Blanchard 

Abstract 

The eastern Bernalillo County study area consists of about 

150 square miles and includes all of Bernalillo County east of 

the crests of the Sandia and Manzanita Mountains. Soil and 

unconsolidated alluvial deposits overlie fractured and solutionchanneled limestone in most of the study area. North of Interstate Highway 40 and east of New Mexico Highway 14, the 

uppermost consolidated geologic units are fractured sandstones 

and shales. Average annual precipitation at three long-term 

National Oceanic and Atmospheric Administration precipitation and snowfall data-collection sites was 14.94 inches at 

approximately 6,300 feet (Sandia Ranger Station), 19.06 inches 

at about 7,020 feet (Sandia Park), and 23.07 inches at approximately 10,680 feet (Sandia Crest). The periods of record at 

these sites are 1933-74, 1939-2001, and 1953-79, respectively. 

Average annual snowfall during these same periods of record 

was 27.7 inches at Sandia Ranger Station, 60.8 inches at Sandia 

Park, and 115.5 inches at Sandia Crest. Seven precipitation 

data-collection sites were established during December 2000– 

March 2001. Precipitation during 2001-03 at three U.S. Geological Survey sites ranged from 66 to 94 percent of period-ofrecord average annual precipitation at corresponding National 

Oceanic and Atmospheric Administration long-term sites in 

2001, from 51 to 75 percent in 2002, and from 34 to 81 percent 

during January through September 2003. Missing precipitation 

records for one site resulted in the 34-percent value in 2003. 

Analyses of concentrations of chlorofluorocarbons CFC-11, 

CFC-12, and CFC-113 in ground-water samples from nine 

wells and one spring were used to estimate when the sampled 

water entered the ground-water system. Apparent ages of 

ground water ranged from as young as about 10 to 16 years to 

as old as about 20 to 26 years. Concentrations of dissolved 

nitrates in samples collected from 24 wells during 2001-02 were 

similar to concentrations in samples collected from the same 

wells during 1995, 1997, and (or) 1998. Nitrate concentrations 

in two wells were larger than the U.S. Environmental Protection 

Agency primary drinking-water regulation of 10 milligrams per 

liter in 1998 and in 2001. Ground-water levels were measured 

during June and July 2002 and during June, July, and August 

2003 in 18 monitoring wells. The median change in water level 

for all 18 wells was a decline of 2.03 feet. 

Introduction 

Unincorporated areas of eastern Bernalillo County, New 

Mexico, have undergone rapid development and population 

increases in recent years, and the demand for water and the 

potential for contamination of ground water have increased 

accordingly. Ground water is the source of domestic supply 

throughout the area, and water for most homes is supplied by 

individual domestic wells or by small community water systems. Most homes use septic systems for the disposal of wastewater. Concentrations of nitrate, measured as nitrate plus nitrite, 

have routinely exceeded the U.S. Environmental Protection 

Agency (USEPA) primary drinking-water regulation of 10 milligrams per liter (mg/L) at certain wells (U.S. Environmental 

Protection Agency, 2002). 

For Bernalillo County to effectively manage and protect 

ground-water resources in the eastern Bernalillo County area, 

the U.S. Geological Survey (USGS) and Bernalillo County 

have been cooperatively conducting ongoing ground-water 

investigations in eastern Bernalillo County since 1990. This 

report was prepared in cooperation with Bernalillo County. 

Purpose and Scope 

This report presents interpretations of historical precipitation data and precipitation data collected during 2001-03, estimated ground-water age data collected during 2003, nitrate concentration changes from 1995-98 to 2002, and ground-waterlevel changes from 2002 to 2003. Precipitation data collected at 

three sites by the National Oceanic and Atmospheric Administration (NOAA) were summarized and additional precipitation 

data were collected during 2001-03 at seven sites established by 

the USGS. Ground-water ages were estimated by analysis of 

chlorofluorocarbon concentrations in samples collected from 

nine wells and one spring during 2002-03. Nitrate concentrations in samples collected from 24 wells during 2001-02 (Blanchard, 2003) were compared with concentrations in samples 

collected from the same wells during 1995-98 (Rankin, 2000). 

Ground-water levels measured in 18 wells during the summer 

of 2003 were compared to levels measured in the same wells 

during the summer of 2002 (Blanchard, 2003). 
2 Precipitation; Ground-Water Age; Nitrate Concentrations; and Levels in Eastern Bernalillo County, New Mexico 

Description of the Study Area 

The eastern Bernalillo County study area consists of about 

150 square miles and includes all of Bernalillo County east of 

the crests of the Sandia and Manzanita Mountains (fig. 1). The 

land surface generally slopes away from the Sandia and Manzanita Mountains toward the east. North of Interstate 40, drainages typically flow east out of the Sandia Mountains, then either 

north out of the study area or south into Tijeras Canyon. South 

of Interstate 40, drainages typically flow east out of the Manzanita Mountains and then either north to Tijeras Canyon or south 

and then west out of the study area. Further east, drainages generally flow north out of Bernalillo County in the northern part 

of the study area, to Tijeras Canyon in the central part of the 

study area, or east out of Bernalillo County in the southern part 

of the study area. 

Soil and unconsolidated alluvial deposits overlie fractured 

and solution-channeled limestone in about three-fourths of the 

study area (fig. 2). Where present, this carbonate terrane is the 

primary source of ground water. In the central part of the study 

area, primarily north of Interstate Highway 40 and east of New 

Mexico Highway 14, the uppermost consolidated geologic units 

are fractured sandstones and shales (fig. 2); the sandstone units 

are sources of ground water in this area. Igneous and metamorphic rocks crop out in Tijeras Canyon and tributary canyons, 

which separate the southern terminus of the Sandia Mountains 

from the northern terminus of the Manzanita Mountains (fig. 2). 

These rocks and overlying unconsolidated deposits derived 

from them are sources of ground water in the Tijeras Canyon 

area. 

The direction of ground-water flow is similar to the direction of surface-water flow described above (fig. 3). In the northern part of the study area, ground water flows east from the crest 

of the Sandia Mountains, then either north out of the study area 

or south to Tijeras Canyon. A ground-water divide is located 

further east, west of which ground water also flows either north 

out of the study area or south to Tijeras Canyon and east of 

which ground water flows east out of the study area. The 

ground-water divide bisects the southern part of the study area. 

West of the divide, ground water flows either northwest to 

Tijeras Canyon or southwest out of the study area; east of the 

divide, ground water flows east out of the study area. 

Acknowledgments 

The cooperation of private well owners, whose permission 

facilitated collection of water samples from and measurement 

of depths to water in their wells, is gratefully acknowledged. 

The cooperation and assistance of employees of the U.S. Forest 

Service and the Natural Resources Conservation Service also 

are gratefully acknowledged. 

Precipitation 

Seven precipitation data-collection sites were established 

by the USGS during December 2000–March 2001 as part of this 

study (fig. 1; table 1). These sites include three in the Sandia 

Mountains (sites 1-3), three in the Manzanita Mountains (sites 

4-6), and one located at a private residence near the Sandia 

Ranger Station (site 7). Monthly and annual precipitation data 

collected during 2001-03 at these sites are listed in table 10 

(tables 10-16 are in supplemental data in the back of the report). 

NOAA operated three long-term precipitation and snowfall data-collection sites in eastern Bernalillo County (fig. 1; 

table 1). Presently (2003), however, none of these sites is in 

operation. The site at Sandia Crest (site 8) was operated during 

1953-79, the site at Sandia Park (site 9) was operated during 

1939-2001, and the site at the Sandia Ranger Station (site 10) 

was operated during 1933-74. Monthly and annual precipitation 

data for these sites for their periods of record are listed in tables 

11-13; monthly and annual snowfall data for these sites for their 

periods of record are listed in tables 14-16. 

Precipitation at National Oceanic and Atmospheric 

Administration Sites 

Data collected at the three NOAA precipitation sites 

(National Oceanic and Atmospheric Administration, 2002) 

were analyzed to determine long-term average monthly and 

annual precipitation and snowfall characteristics. Two data sets 

were analyzed. The first set includes data for the entire period 

of record at each site; the second set includes 1954-74, when all 

three sites were operating. 

Precipitation during 1954-74 was very similar to but 

slightly less than the periods of record at the three NOAA sites. 

Average annual precipitation during 1954-74 ranged from 97.6 

to 98.5 percent of that during the periods of record (tables 2 and 

3). Monthly and annual precipitation data for these sites for 

their periods of record including 1954-74 are listed in tables 11-

13. 

Annual precipitation in eastern Bernalillo County 

increases with altitude. Period-of-record average annual precipitation at the three NOAA sites was 14.94 inches at 6,304 feet 

(Sandia Ranger Station), 19.06 inches at 7,017 feet (Sandia 

Park), and 23.07 inches at 10,683 feet (Sandia Crest) (table 2). 

The wettest months at the three NOAA sites typically were 

July and August, during which about 29 to 32 percent of annual 

precipitation or about 14 to 16 percent of annual precipitation 

per month fell (fig. 4; table 2). The driest months typically were 

April through June, during which about 14 to 19 percent of 

annual precipitation or about 5 to 6 percent of average annual 

precipitation per month fell (fig. 4; table 2). 

During December through March, when precipitation typically falls as snow, the percentage of annual precipitation 

increases with altitude. Using average monthly and annual values for the respective periods of record, about 26 percent of 
Precipitation 3

Figure 1. Location of study area and data-collection sites, eastern Bernalillo County, New Mexico.
4 Precipitation; Ground-Water Age; Nitrate Concentrations; and Levels in Eastern Bernalillo County, New Mexico 

Figure 2. Geologic terranes in eastern Bernalillo County, New Mexico. 
Precipitation 5 

Figure 3. Approximate ground-water divide and general direction of ground-water flow in eastern Bernalillo County, 

New Mexico. 
6 Precipitation; Ground-Water Age; Nitrate Concentrations; and Levels in Eastern Bernalillo County, New Mexico 

Table 1. Precipitation sites in the eastern Bernalillo County study area. 

[Identification number: for sites 1-7, first 13 digits are the latitude and longitude of the site, and last two digits are the sequence number of that site's latitude and 

longitude; for sites 8-10, number assigned by National Oceanic and Atmospheric Administration (NOAA) or U.S. Geological Survey (USGS). USFS, U.S. Forest 

Service; altitude in feet above NGVD29] 

Site 

number 

(fig. 1) 

Identification 

number 

Responsible 

agency 

General location Altitude 

(feet) Period of record 

1 351228106261130 USGS Sandia Mountains high altitude 10,030 03/02/2001 - present 

2 351054106233330 USGS Sandia Mountains intermediate altitude 8,020 03/01/2001 - present 

3 350948106212630 USGS Sandia Mountains low altitude 7,030 01/17/2001 - present 

4 345848106214730 USGS Manzanito Mountains high altitude 7,550 03/01/2001 - 10/031 

5 345853106195130 USGS Manzanito Mountains intermediate altitude 7,460 01/25/2001 - present 

6 345318106135430 USGS Manzanito Mountains low altitude 6,780 12/29/2000 - present 

7 350434106230501 USGS Tijeras, N. Mex. 6,350 03/08/2001 - present 

8 298011 NOAA Sandia Crest, N. Mex. 10,683 11/01/1953 - 04/30/1979 

9 298015 NOAA Sandia Park, N. Mex. 7,017 01/01/1939 - 11/30/2001 

10 298018 NOAA USFS Sandia Ranger Station, N. Mex. 6,304 01/01/1933 - 12/31/1974 

1

Site 4 was vandalized and rendered inoperable on an unknown date in October 2003. 

annual precipitation falls during these months at Sandia Ranger 

Station (altitude 6,304 feet), about 28 percent falls during these 

months at Sandia Park (altitude 7,017 feet), and about 

36 percent falls during these months at Sandia Crest (altitude 

10,683 feet) (fig. 4; table 2). 

Snowfall at National Oceanic and Atmospheric 

Administration Sites 

The 1954-74 average annual snowfall ranged from about 

one-half the period-of-record average annual snowfall at Sandia 

Ranger Station, to slightly less than the period-of-record average annual snowfall at Sandia Park, to about the same as the 

period-of-record average annual snowfall at Sandia Crest 

(tables 4 and 5). The 1954-74 average annual snowfall was 

about 54 percent of the period-of-record average annual snowfall at the Sandia Ranger Station, about 93 percent of that at 

Sandia Park, and more than 99 percent of that at Sandia Crest. 

Monthly and annual snowfall data at these sites for their periods 

of record including 1954-74 are listed in tables 14-16. 

Annual snowfall in eastern Bernalillo County increases 

with altitude. Period-of-record average annual snowfall at the 

three NOAA sites was 27.7 inches at 6,304 feet (Sandia Ranger 

Station), 60.8 inches at 7,017 feet (Sandia Park), and 

115.5 inches at 10,683 feet (Sandia Crest) (table 4). 

Snow can fall in the Sandia Mountains during nearly any 

time of the year (fig. 5; table 4). At least a trace of snowfall has 

been recorded in every month of the year except July and 

August at Sandia Ranger Station, in every month of the year at 

Sandia Park, and in every month of the year except August at 

Sandia Crest. About 74 to 78 percent of annual snow, however, 

falls during December through March at the three sites. 

Precipitation at U.S. Geological Survey Sites 

In the Sandia and Manzanita Mountains, high-altitude 

(sites 1 and 4), intermediate-altitude (sites 2 and 5), and lowaltitude (sites 3, 6, and 7) precipitation data-collection sites 

were established (fig. 1; table 1). The differences in altitude 

between the high- and low-altitude sites are about 3,000 feet in 

the Sandia Mountains and about 1,200 feet in the Manzanita 

Mountains. The NOAA long-term precipitation sites at Sandia 

Crest (site 8), Sandia Park (site 9), and the Sandia Ranger Station (site 10) correspond closely in location and altitude with 

USGS sites 1, 3, and 7, respectively (fig. 1; table 1). 

Precipitation at USGS sites 1-6 was measured continually 

at 1-hour intervals using a tipping-bucket rain gage connected 

to a data recorder. During winter months, a precipitation adapter 

was added to accommodate snowfall collection. Precipitation 

data were downloaded onsite from the data recorder to a laptop 

computer and then processed in the office. Precipitation at 

USGS site 7 was measured once per day using a 4-inch-diameter cylindrical rain gage with an inner cylinder graduated at 

0.01-inch intervals. Data collected at sites 1-7 are stored in the 

USGS National Water Information System (NWIS) database. 

Annual precipitation during 2001-03 was less than typical 

in eastern Bernalillo County (figs. 6-8; table 6). Precipitation at 

USGS sites 1, 3, and 7 ranged from 66 to 94 percent of periodof-record average annual precipitation at corresponding NOAA 

sites in 2001, ranged from 51 to 75 percent in 2002, and ranged 

from 34 to 81 percent in 2003 (table 6). The 34 percent of average annual precipitation at site 1 during 2003, however, is based 

on incomplete data during June and August and no data during 

July. During 2001-03, monthly precipitation was less than average at site 1 in 27 of 31 months (excluding June and August 

2003), at site 3 in 28 of 35 months, and at site 7 in 24 of 

34 months (figs. 6-8; table 6). 
Table 2. Monthly and annual precipitation, in inches, at National Oceanic and Atmospheric Administration precipitation stations, periods of record.

 Jan Feb Mar Apr May June July Aug Sept Oct N

Sandia Crest - Site 8, 1953-79 

Years 26 26 26 26 25 25 25 25 25 25 25 Total 51.75 50.68 60.89 33.47 23.01 23.63 79.82 85.07 45.48 45.63 34Minimum 0.17 0.30 Trace 0.01 0.05 Trace 0.49 1.42 0.07 0.00 0Maximum 4.84 4.93 6.55 3.21 2.52 3.88 6.23 7.64 4.62 5.79 Average 1.99 1.95 2.34 1.29 0.92 0.95 3.19 3.40 1.82 1.83 Percent of annual 8.63 8.45 10.15 5.58 3.99 4.10 13.84 14.75 7.89 7.91 5

Sandia Park - Site 9, 1939-2001 

Years 60 55 57 58 60 60 61 60 59 57 59 Total 77.51 65.04 88.74 57.68 65.67 61.48 177.21 187.22 100.92 87.81 79Minimum 0.02 0.00 Trace 0.00 0.00 Trace 0.19 0.95 0.00 0.00 0Maximum 3.87 2.68 4.18 3.25 3.96 5.50 7.40 6.52 5.49 5.57 4Average 1.29 1.18 1.56 0.99 1.09 1.02 2.91 3.12 1.71 1.54 Percent of annual 6.78 6.20 8.17 5.22 5.74 5.38 15.24 16.37 8.97 8.08 7

Sandia Ranger Station - Site 10, 1933-74 

Years 39 39 39 39 38 39 39 39 39 39 39 Total 34.10 30.56 43.19 39.65 40.96 31.27 89.86 92.94 51.37 52.18 32Minimum 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.52 0.00 0.00 0Maximum 5.21 1.91 3.37 4.85 6.55 3.25 4.59 4.77 3.63 5.82 2Average 0.87 0.78 1.11 1.02 1.08 0.80 2.30 2.38 1.32 1.34 0Percent of annual 5.85 5.24 7.41 6.80 7.21 5.37 15.42 15.95 8.82 8.96 5
Table 3. Monthly and annual precipitation, in inches, at National Oceanic and Atmospheric Administration precipitation stations, 1954-74.

 Jan Feb Mar Apr May June July Aug Sept Oct No

Sandia Crest - Site 8 

Years 21 21 21 21 21 21 21 21 21 21 21 Total 36.62 36.09 47.36 25.80 19.24 20.16 66.99 71.36 36.34 43.23 28.1Minimum 0.17 0.30 Trace 0.01 0.05 0.00 0.49 1.42 0.07 0.05 0.1Maximum 4.10 2.86 6.55 3.21 2.52 3.88 6.23 7.64 4.56 5.79 3.6Average 1.74 1.72 2.26 1.23 0.92 0.96 3.19 3.40 1.73 2.06 1.3Percent of annual 7.7 7.6 9.9 5.4 4.0 4.2 14.0 15.0 7.6 9.1 5.9 

Sandia Park - Site 9 

Years 20 19 19 20 20 20 21 21 20 19 20 Total 19.73 23.18 26.35 18.25 20.85 19.00 65.14 66.00 34.46 31.94 22.7Minimum 0.08 0.07 Trace 0.00 0.05 Trace 0.20 0.95 0.00 0.14 0.2Maximum 2.75 2.62 3.44 3.02 3.47 4.19 6.18 5.23 5.49 5.57 3.3Average 0.99 1.22 1.39 0.91 1.04 0.95 3.10 3.14 1.72 1.68 1.1Percent of annual 5.3 6.5 7.4 4.9 5.6 5.1 16.6 16.8 9.2 9.0 6.1 

Sandia Ranger Station - Site 10 

Years 21 21 21 21 21 21 21 21 21 21 21 Total 14.80 17.66 22.42 16.87 14.99 15.77 50.72 50.72 29.11 33.33 14.6Minimum 0.00 0.00 0.00 0.00 0.00 0.00 0.62 0.52 0.06 0.00 0.0Maximum 1.86 1.91 3.29 2.58 2.92 3.25 4.01 4.77 3.63 4.90 1.9Average 0.70 0.84 1.07 0.80 0.71 0.75 2.42 2.42 1.39 1.59 0.7Percent of annual 4.8 5.8 7.3 5.5 4.9 5.2 16.6 16.6 9.5 10.9 4.8 
Precipitation 9 

Figure 4. Average monthly precipitation at Sandia Crest, Sandia Park, and Sandia Ranger Station, periods of record. 
Table 4. Monthly and annual snowfall, in inches, at National Oceanic and Atmospheric Administration precipitation stations, periods of record.

 Jan Feb Mar Apr May June July Aug Sept Oct Nov 

Sandia Crest - Site 8, 1953-79 

Years 25 25 26 26 24 25 25 25 25 24 24 Total 483.9 556.9 594.9 277.5 90.9 1.5 1.0 0.0 2.8 131.4 239.Minimum 1.9 2.0 Trace 0.0 0.0 0.0 0.0 0.0 0.0 0.0 TracMaximum 45.8 60.3 67.9 34.5 21.3 1.0 1.0 0.0 1.5 24.0 27.6 Average 19.4 22.3 22.9 10.7 3.8 0.1 0.0 0.0 0.1 5.5 10.0 Percent of annual 16.8 19.3 19.8 9.2 3.3 0.1 0.0 0.0 0.1 4.7 8.6 

Sandia Park - Site 9, 1939-2001 

Years 53 52 52 51 59 60 61 60 60 52 56 Total 736.3 577.8 570.2 239.4 26.1 0.0 0.0 0.0 2.8 76.9 415.5 Minimum 0.9 Trace Trace 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Maximum 43.0 32.5 40.0 24.5 14.4 Trace Trace Trace Trace Trace 35.0 Average 13.9 11.1 11.0 4.7 0.4 0.0 0.0 0.0 0.0 1.5 7.4 Percent of annual 22.8 18.3 18.0 7.7 0.7 0.0 0.0 0.0 0.1 2.4 12.2 

Sandia Ranger Station - Site 10, 1933-74 

Years 32 28 27 38 41 42 41 42 41 40 33 Total 213.2 137.9 111.6 76.0 26.0 0.0 0.0 0.0 7.5 0.0 104.0 Minimum 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Maximum 23.7 24.0 18.6 16.0 18.0 Trace 0.0 0.0 6.5 Trace 23.5 Average 6.7 4.9 4.1 2.0 0.6 0.0 0.0 0.0 0.2 0.0 3.2 Percent of annual 24.1 17.8 14.9 7.2 2.3 0.0 0.0 0.0 0.7 0.0 11.4 
Table 5. Monthly and annual snowfall, in inches, at National Oceanic and Atmospheric Administration precipitation stations, 1954-74.

 Jan Feb Mar Apr May June July Aug Sept Oct No

Sandia Crest - Site 8 

Years 21 21 21 21 21 21 21 21 21 21 20 Total 376.6 462.9 496.3 219.4 68.6 1.5 1.0 0.0 2.8 129.2 200.Minimum 1.9 2.0 Trace 0.0 0.0 0.0 0.0 0.0 0.0 0.0 TracMaximum 40.5 60.3 67.9 34.5 17.3 Trace 1.0 0.0 0.0 24.0 27.Average 17.9 22.0 23.6 10.4 3.3 0.1 0.0 0.0 0.1 6.2 10.Percent of annual 15.6 19.2 20.5 9.1 2.8 0.1 0.0 0.0 0.1 5.3 8.

Sandia Park - Site 9 

Years 15 17 14 13 20 20 21 21 20 17 18 Total 183.3 173.3 159.3 57.1 2.6 0.0 0.0 0.0 0.8 10.1 100.Minimum 1.0 1.0 Trace 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.Maximum 35.9 26.5 40.0 24.5 2.0 Trace Trace Trace 0.8 3.6 17.Average 12.2 10.2 11.4 4.4 0.1 0.0 0.0 0.0 0.0 0.6 5.Percent of annual 21.7 18.1 20.2 7.8 0.2 0.0 0.0 0.0 0.1 1.1 9.

Sandia Ranger Station - Site 10 

Years 12 10 9 17 21 21 21 21 20 19 15 Total 44.1 23.3 19.9 16.0 0.0 0.0 0.0 0.0 0.0 0.0 9.Minimum 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.Maximum 17.0 9.0 13.5 16.0 Trace Trace 0.0 0.0 0.0 Trace 3.Average 3.7 2.3 2.2 0.9 0.0 0.0 0.0 0.0 0.0 0.0 0.Percent of annual 24.7 15.6 14.8 6.3 0.0 0.0 0.0 0.0 0.0 0.0 4.
12 Precipitation; Ground-Water Age; Nitrate Concentrations; and Levels in Eastern Bernalillo County, New Mexico 

Figure 5. Average monthly snowfall at Sandia Crest, Sandia Park, and Sandia Ranger Station, periods of record. 
Precipitation 13 

Figure 6. Average monthly precipitation at site 8, Sandia Crest, 1953-79, and monthly precipitation at site 1, Sandia Mountains 

high altitude, 2001-03. 
14 Precipitation; Ground-Water Age; Nitrate Concentrations; and Levels in Eastern Bernalillo County, New Mexico 

3.50 

3.00 

2.50 

2.00 

1.50 

1.00 

0.50 

0.00 

Sandia Park (site 9) average 

Site 3, 2001 

Site 3, 2002 

PRECIPITATION, IN INCHES 

Site 3, 2003 

Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec 

Figure 7. Average monthly precipitation at site 9, Sandia Park, 1939-2001, and monthly precipitation at site 3, Sandia Mountains 

low altitude, 2001-03. 
Precipitation 15 

Figure 8. Average monthly precipitation at site 10, Sandia Ranger Station, 1933-74, and monthly precipitation at site 7, Tijeras, 

New Mexico, 2001-03. 
Table 6. Comparison of average monthly and annual precipitation at National Oceanic and Atmospheric Administration precipitation sites and mont

at U.S. Geological Survey and volunteer precipitation sites. 

[Percent, percentage of period-of-record precipitation; ND, no data. Bold number: site 1, June 2003, 13 days of data estimated to be missing; site 1, August 2003, 29 days of data 

January 2001, 17 days of data missing] 

Site Jan Feb Mar Apr May June July Aug Sept Oct Nov 

Sandia Crest (site 8) 1953-79 average compared with USGS site 1, 2001-03 

Sandia Crest average 1.99 1.95 2.34 1.29 0.92 0.95 3.19 3.40 1.82 1.83 1.38 Site 1, 2001 ND ND 1.79 0.97 0.00 0.00 0.19 3.73 0.51 0.28 1.79 Departure -0.55 -0.32 -0.92 -0.95 -3.00 0.33 -1.31 -1.55 0.41 Sandia Crest average 1.99 1.95 2.34 1.29 0.92 0.95 3.19 3.40 1.82 1.83 1.38 Site 1, 2002 1.49 1.19 0.01 1.53 0.39 0.37 2.21 0.09 1.21 1.45 0.97 Departure -0.50 -0.76 -2.33 0.24 -0.53 -0.58 -0.98 -3.31 -0.61 -0.38 -0.41 -Sandia Crest average 1.99 1.95 2.34 1.29 0.92 0.95 3.19 3.40 1.82 1.83 1.38 Site 1, 2003 0.22 0.80 1.34 0.70 0.30 0.37 ND 0.28 0.94 1.47 0.03 Departure -1.77 -1.15 -1.00 -0.59 -0.62 -0.58 -3.12 -0.88 -0.36 -1.35 -

Sandia Park (site 9) 1939-2001 average compared with USGS site 3, 2001-03 

Sandia Park average 1.29 1.18 1.56 0.99 1.09 1.02 2.91 3.12 1.71 1.54 1.34 Site 3, 2001 1.32 1.18 1.35 1.14 0.73 0.62 1.86 2.56 0.23 0.27 1.17 Departure 0.03 0.00 -0.21 0.15 -0.36 -0.40 -1.05 -0.56 -1.48 -1.27 -0.17 Sandia Park average 1.29 1.18 1.56 0.99 1.09 1.02 2.91 3.12 1.71 1.54 1.34 Site 3, 2002 1.01 0.00 0.10 0.36 0.43 0.03 2.32 0.92 2.07 0.85 0.90 Departure -0.28 -1.18 -1.46 -0.63 -0.66 -0.99 -0.59 -2.20 0.36 -0.69 -0.44 -Sandia Park average 1.29 1.18 1.56 0.99 1.09 1.02 2.91 3.12 1.71 1.54 1.34 Site 3, 2003 1.09 2.53 1.34 0.24 1.03 1.65 0.72 2.87 0.58 1.32 1.36 Departure -0.20 1.35 -0.22 -0.75 -0.06 0.63 -2.19 -0.25 -1.13 -0.22 0.02 -

Sandia Ranger Station (site 10) 1933-74 average compared with USGS site 7, 2001-03 

Sandia Ranger Station average 0.87 0.78 1.11 1.02 1.08 0.80 2.30 2.38 1.32 1.34 0.82 Site 7, 2001 ND ND 0.88 0.95 0.67 1.30 3.18 2.46 0.49 0.21 1.56 Departure -0.23 -0.07 -0.41 0.50 0.88 0.08 -0.83 -1.13 0.74 -Sandia Ranger Station average 0.87 0.78 1.11 1.02 1.08 0.80 2.30 2.38 1.32 1.34 0.82 Site 7, 2002 0.46 0.07 0.01 0.68 0.13 0.41 3.68 1.04 2.53 1.05 0.60 Departure -0.41 -0.71 -1.10 -0.34 -0.95 -0.39 1.38 -1.34 1.21 -0.29 -0.22 -Sandia Ranger Station average 0.87 0.78 1.11 1.02 1.08 0.80 2.30 2.38 1.32 1.34 0.82 Site 7, 2003 0.01 1.81 0.97 0.19 0.26 1.02 0.44 2.46 0.84 0.79 1.27 Departure -0.86 1.03 -0.14 -0.83 -0.82 0.22 -1.86 0.08 -0.48 -0.55 0.45 -
Ground-Water Age 

Analyses of selected chlorofluorocarbon (CFC) concentrations in ground-water samples from nine wells and one spring 

were used to estimate when the sampled water entered the 

ground-water system and, therefore, the age or residence time 

of water in the ground-water system. Samples were collected, 

processed, and shipped during February and April 2003 according to procedures developed by the USGS Reston Chlorofluorocarbon Laboratory in Reston, Virginia (U.S. Geological Survey, 2003). The sampling procedure isolates the sample from 

exposure to and contamination by ambient air. 

The selected chlorofluorocarbons, CFC-11, CFC-12, and 

CFC-113, have been used as refrigerants and aerosol propellants since about 1940. The concentration of each CFC in the 

atmosphere and, therefore, in recharge water that is in equilibrium with the atmosphere, has been measured or reconstructed 

for 1940 to the present (2003). The concentrations of these 

chemicals in ground-water samples provide an estimate of 

when the sampled water entered the ground-water system. 

Several conditions, however, can occur during movement 

of water through soil and bedrock to the ground-water system 

and within the ground-water system that affect CFC concentrations in ground water (Plummer and Busenberg, 1999). Processes and conditions that potentially occur in eastern Bernalillo County include excess air entrapped in the water, thick 

unsaturated zones, and recharge occurring at high but variable 

altitudes combined with mixing of water in the ground-water 

system. 

Excess air can become entrapped and subsequently dissolved in water that rapidly enters the ground-water system, 

resulting in an apparent age that is too young (Plummer and 

Busenberg, 1999). Most of eastern Bernalillo County is underlain by fractured and solution-channeled limestone (Titus, 

1980), which has the potential to facilitate rapid movement of 

recharge water through the unsaturated zone to the water table. 

Ground-water levels have been observed to rise relatively rapidly following a large precipitation event or a series of such 

events (Blanchard and Kues, 1999), suggesting that water 

moves rapidly through the unsaturated zone to the water table. 

The age of ground water can appear to be older than it actually is when the unsaturated-zone thickness is more than about 

30 feet and older by 8 to 12 years when the thickness of the 

unsaturated is about 100 feet (Plummer and Busenberg, 1999). 

Depths to water in four of the nine wells sampled for CFC’s 

ranged from about 100 to about 194 feet. Depth to water in a 

fifth well was about 75 feet; depths to water in the remaining 

four wells were less than 50 feet. 

Recharge at high altitudes and attendant low barometric 

pressure can result in CFC concentrations that suggest a 

ground-water age that is too old (Plummer and Busenberg, 

1999). Recharge altitudes have been estimated for the wells and 

spring sampled for CFC’s, but recharge can potentially occur 

nearly anywhere in eastern Bernalillo County. Recharge to the 

ground-water system in which a particular well is completed 

Ground-Water Age 17 

likely occurs at a range of altitudes along flow paths intercepted 

by the well. For example, recharge to a well located east of the 

Sandia Mountains at an altitude of 7,000 feet could occur near 

the well in addition to upgradient along the ground-water flow 

path to as high as about 10,000 feet near the crest of the Sandia 

Mountains. 

Apparent ground-water ages, as determined by analysis of 

CFC concentrations in samples collected from nine wells and 

one spring, are shown in figure 9 and listed in table 7. Groundwater ages ranged from about 10 to 16 years in an alluvial drainage composed of unconsolidated material eroded from the adjacent Sandia Mountains (sites 14 and 15); from 14 to 19 years 

along Tijeras Canyon and Interstate 40 including near the eastern boundary of the study area (sites 17-19); from 17 to 19 years 

in and immediately east of the Sandia Mountains (Cienega 

Spring and sites 29 and 30); and from 20 to 23 years (site 4) and 

20 to 26 years (site 8) in fractured and solution-channeled limestone in the southern part of the study area (Julian E. Wayland, 

U.S. Geological Survey Dissolved Gas Laboratory, written 

commun., July 16, 2003). Disregarding sites 14 and 15 where 

the ground-water system is in unconsolidated material and 

using the median ground-water ages for the remaining eight 

sites, the range in ground-water age in consolidated rocks 

throughout the study area is about 16.5 to 23 years. This young 

age and the similarity in ground-water ages throughout the 

study area suggest that recharge occurs rapidly through fractured and solution-channeled limestone and that recently 

recharged ground water mixes with older water in the groundwater system along flow paths upgradient from the sampled 

wells. 

Dissolved Nitrate Concentrations, 1995-2002 

Concentrations of dissolved nitrate plus nitrite were measured in samples from 24 wells during 2001-02. Concentrations 

in these wells also were measured in samples collected during 

1995, 1997, and (or) 1998 (fig. 10; table 8). Samples were collected during 1995, 1997, and 1998 according to standard 

USGS procedures described by Fishman and Friedman (1989); 

samples were collected during 2001-02 following standard 

USGS procedures described by Wilde and others (1998). Laboratory analysis of samples was conducted by the USGS 

National Water-Quality Laboratory (NWQL) in Denver, Colorado, according to procedures described by Fishman and Friedman (1989). In the laboratory, concentrations of dissolved 

nitrate plus nitrite and concentrations of dissolved nitrite were 

measured; concentrations of dissolved nitrate were calculated 

by subtracting the nitrite concentrations from the nitrate plus 

nitrite concentrations. 

Concentrations of dissolved nitrite were less than the minimum reporting level of 0.010 mg/L in all but four samples collected during 1995, 1997, and 1998, and were less than the minimum reporting level of 0.008 mg/L in all but one sample 

collected during 2001-02. Minimum reporting levels are 
18 Precipitation; Ground-Water Age; Nitrate Concentrations; and Levels in Eastern Bernalillo County, New Mexico

Figure 9. Estimated age of ground water in selected monitoring wells and spring as determined by concentrations of 

chlorofluorocarbons.
Table 7. Estimated ground-water age determined by concentrations of chlorofluorocarbons. 

[CFC, chlorofluorocarbon] 

Well number/ CFC used Approxispring name Site identification to estimate mate age 

(fig. 9) age (years) 

4 345726106170401 11, 12, 113 20 to 23 

8 345833106185101 113 20 to 26 

14 350410106262601 113 10 to 16 

15 350423106263301 12, 113 10 to 16 

17 350449106231901 113 14 to 19 

18 350522106222501 113 14 to 19 

19 350525106151701 11, 12, 113 14 to 19 

29 350949106211301 12, 113 17 to 19 

30 351011106220401 12, 113 17 to 19 

Cienega Spring 351012106230401 12, 113 17 to 19 

established by the NWQL. The concentrations of dissolved 

nitrite in samples collected from wells 17, 22, and 24 in 1995 

were 0.010, 0.020, and 0.020 mg/L, respectively; the concentration in the sample collected from well 7 in 1998 was unusually 

large: 0.942 mg/L. The concentrations of nitrate shown in figure 

10 and listed in table 8 for these four samples were determined 

by subtracting the concentration of nitrite from the concentration of nitrate plus nitrite. The concentration of dissolved nitrite 

in the sample collected from well 8 in 2002 was less than 

0.010 mg/L. Concentrations of dissolved nitrite in this sample 

and all other samples (all less than 0.010 mg/L) were considered 

to be insignificant. 

Concentrations of dissolved nitrate were grouped into four 

categories: 

1.	 Less than 0.050 to 0.999 mg/L; considered to be at or near 

background concentrations, 

2.	 1.00 to 4.99 mg/L; considered to be larger than 


background concentrations, but not large enough to 


prompt concern regarding health concerns,


3.	 5.00 to 9.99 mg/L; considered to be larger than 

background concentrations and large enough to prompt 

concern regarding health concerns, and 

4.	 10.0 or more mg/L; larger than the USEPA primary 


drinking-water regulation, which is based on health 


concerns. 


Dissolved nitrate concentrations in samples collected from 

17 of the 24 wells during 2001-02 were less than 5.0 mg/L, and 

concentrations in 10 of these samples were less than 1.0 mg/L 

(fig. 10; table 8). Concentrations in samples collected from five 

Ground-Water-Level Changes, 2002-03 19 

wells during 2001-02 were between 5.0 and 9.99 mg/L (wells 5, 

19, 21, 23, and 25). Concentrations in wells 14 (16.5 mg/L) and 

26 (20.0 mg/L) were larger than the USEPA primary drinkingwater regulation of 10 mg/L; these concentrations, however, 

were less than those in the previous samples collected during 

1998. Wells 14 and 26 are located in areas of residential development where septic tanks and leach fields are used. 

Dissolved nitrate concentrations in samples collected during 2001-02 typically were consistent with those collected during 1995, 1997, and 1998 (table 8). Dissolved nitrate concentrations in samples collected during 2001-02 were in the same 

concentration category as concentrations in samples collected 

during 1995-98 in all wells except 7, 8, and 22, in which concentrations decreased and were classified in a smaller concentration category. From 1998 to 2002, dissolved nitrate concentrations decreased from 6.08 to 3.96 mg/L in well 7; from 

1995 to 2001, concentrations steadily decreased from 7.18 to 

0.892 mg/L in four samples collected from well 22. 

Dissolved nitrate concentrations in samples collected 

during 2001-02 were larger than the largest 1995-98 concentration in 8 of the 24 wells; increases, however, were less than 

1.0 mg/L in 6 of these wells. Dissolved nitrate concentrations in 

wells 5 and 25 during 2001-02 were 1.60 and 3.56 mg/L larger, 

respectively, than the previous largest concentration and were 

more than 9.0 mg/L in 2002. 

Ground-Water-Level Changes, 2002-03 

Ground-water levels were measured during June and July 

2002 and during June, July, and August 2003 in 18 monitoring 

wells. Four wells were inactive and not regularly supplying 

water and 14 wells were active and supplying water to a residence, commercial establishment, or fire station. Water-level 

changes from 2002 to 2003 are shown in figure 11 and are listed 

in table 9. 

From 2002 to 2003, water-level rises in five wells ranged 

from 0.07 to 1.51 feet, and the median rise was 0.37 foot. 

Water-level declines in 13 wells ranged from 1.11 to 17.66 feet, 

and the median decline was 3.31 feet. The median change in 

water level for all 18 wells was a decline of 2.03 feet. 

In active domestic wells, water levels can be affected by 

changes in the volume of water routinely withdrawn from the 

wells as dictated by habits of the residents. For example, the 

volume of water withdrawn from a well can be affected by a 

change in the number of residents in a home or by the amount 

of time that residents spend in a home. 

Water levels declined more than 8.64 feet in three wells. 

One of these wells was used by a day care facility and one was 

used by an office building (declines of 14.50 and 15.46 feet, 

respectively). The third well was used by a residence in which 

the family changed from two parents and two children to two 

parents and six home-schooled children (decline of 17.66 feet). 
20 Precipitation; Ground-Water Age; Nitrate Concentrations; and Levels in Eastern Bernalillo County, New Mexico

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Figure 10. Change in dissolved nitrate concentrations in selected monitoring wells, 1995-98 to 2001-02.
Ground-Water-Level Changes, 2002-03 21 

Table 8. Nitrate concentrations in monitoring wells, 1995-2002, and change, 2001-02, from most recent 1995-98 

concentration. 

[<, less than; >, greater than] 

Dissolved nitrate as nitrogen Change, 

Well (milligrams per liter) 2001-02, from 

number Site identification most recent 

(fig. 10) 1995 1997 1998 2001-02 1995-98 

concentration 

4 345726106170401 <0.050 <0.050 0 

5 345733106181901 7.46 7.37 9.06 1.69 

6 345754106164601 3.70 2.77 -0.93 

7 345819106200601 6.08 3.96 -2.12 

8 345833106185101 1.30 0.058 -1.242 

11 345948106191701 0.560 0.396 -0.164 

12 350119106210901 4.50 3.22 -1.28 

13 350157106172501 3.82 3.42 -0.40 

14 350410106262601 14.0 14.8 17.9 16.5 -1.4 

15 350423106263301 0.720 0.605 -0.115 

16 350434106225701 1.20 1.34 0.14 

17 350449106231901 0.650 0.235 -0.415 

18 350522106222501 2.60 2.25 -0.35 

19 350525106151701 7.60 7.21 7.58 0.37 

20 350531106224301 <0.050 0.056 >0.006 

21 350604106205801 9.20 8.60 8.75 0.15 

22 350615106223301 7.18 3.25 1.48 0.892 -0.588 

23 350655106185601 9.40 7.07 9.61 2.54 

24 350721106222101 0.310 0.843 0.533 

25 350840106171601 5.80 5.52 9.36 3.84 

26 350930106210701 21.0 16.3 21.0 20.0 -1.0 

29 350949106211801 0.630 0.680 0.300 -0.380 

30 351011106220401 0.130 0.168 0.038 

31 351014106202801 2.70 2.99 0.29 
22 Precipitation; Ground-Water Age; Nitrate Concentrations; and Levels in Eastern Bernalillo County, New Mexico

Figure 11. Change in ground-water levels in selected monitoring wells, 2002-03.
Table 9. Ground-water-level changes in selected monitoring 

wells, 2002-03. 

Water level 

Well 

number Site identification 

(feet below land surface) 

(fig. 11) 2002 2003 Change, 

2002-03 

1 345319106135101 19.88 34.38 -14.50 

2 345348106122601 18.62 21.93 -3.31 

3 345723106171301 96.55 96.48 0.07 

10 345908106153901 194.30 195.96 -1.66 

12 350119106210901 32.31 34.52 -2.21 

13 350157106172501 178.86 187.50 -8.64 

14 350410106262601 71.63 74.97 -3.34 

15 350423106263301 44.27 43.82 0.45 

17 350449106231901 28.50 28.13 0.37 

19 350525106151701 142.09 143.20 -1.11 

20 350531106224301 41.92 59.58 -17.66 

21 350604106205801 34.48 35.67 -1.19 

25 350840106171601 108.08 106.57 1.51 

26 350930106210701 54.50 69.96 -15.46 

27 350945106203101 60.53 62.38 -1.85 

28 350949106184501 180.10 185.68 -5.58 

29 350949106211801 191.70 193.94 -2.24 

30 351011106220401 17.87 17.75 0.12 

Summary 

The eastern Bernalillo County study area consists of about 

150 square miles and includes all of Bernalillo County east of 

the crests of the Sandia and Manzanita Mountains. Unincorporated areas of eastern Bernalillo County have undergone rapid 

development and attendant population increases in recent years, 

and the demand for water and the potential for contamination of 

ground water have increased accordingly. Ground water is the 

source of domestic supply throughout the area, and water for 

most homes is supplied by individual domestic wells or by 

small community water systems. Most homes use septic systems for the disposal of wastewater. 

Soil and unconsolidated alluvial deposits overlie fractured 

and solution-channeled limestone in most of the study area. 

North of Interstate Highway 40 and east of New Mexico Highway 14, the uppermost consolidated geologic units are fractured 

sandstones and shales. 

Average annual precipitation at three long-term NOAA 

precipitation and snowfall data-collection sites during their 

Summary 23 

periods of record was 14.94 inches at approximately 6,300 feet 

(Sandia Ranger Station), 19.06 inches at about 7,020 feet 

(Sandia Park), and 23.07 inches at approximately 10,680 feet 

(Sandia Crest). The periods of record at these sites are 1933-74, 

1939-2001, and 1953-79, respectively. 

The wettest months typically are July and August, during 

which about 29-32 percent of annual precipitation falls; this 

percentage is consistent regardless of altitude. A second seasonal wet period occurs during December through March, and 

the percentage of annual precipitation falling during this wet 

period increases with altitude. The driest months are April 

through June, during which the percentage of annual precipitation ranges from about 14 to 19 percent at the three sites. 

Annual snowfall increases substantially with altitude. 

Average annual snowfall during the periods of record was 

27.7 inches at 6,304 feet (Sandia Ranger Station), 60.8 inches at 

7,017 feet (Sandia Park), and 115.5 inches at 10,683 feet 

(Sandia Crest). 

Snow can fall in the Sandia Mountains during nearly any 

time of the year. At least a trace of snowfall has been recorded 

in every month of the year except July and August at Sandia 

Ranger Station, in every month of the year at Sandia Park, and 

in every month of the year except August at Sandia Crest. About 

74 to 78 percent of annual snow, however, falls during December through March at the three sites. 

Seven precipitation data-collection sites were established 

during December 2000–March 2001. Precipitation during 

2001-03 at three USGS sites ranged from 66 to 94 percent of 

period-of-record average annual precipitation at corresponding 

NOAA long-term sites in 2001, from 51 to 75 percent in 2002, 

and from 34 to 81 percent during January through September 

2003. Missing precipitation records for one site resulted in the 

34-percent value in 2003. During 2001-03, monthly precipitation was less than average at site 1 in 27 of 31 months, at site 3 

in 28 of 35 months, and at site 7 in 24 of 34 months. 

Analyses of selected CFC concentrations in ground-water 

samples from nine wells and one spring were used to estimate 

when the sampled water entered the ground-water system and, 

therefore, the age of ground water at the sampling locations. 

The selected CFC’s, CFC-11, CFC-12, and CFC-113, have 

been used as refrigerants and aerosol propellants since about 

1940. The concentration of each CFC in the atmosphere and, 

therefore, in recharge water that is in equilibrium with the atmosphere, has been measured or reconstructed for 1940 to the 

present (2003). The concentrations of these chemicals in 

ground-water samples provide an estimate of when the sampled 

water entered the ground-water system. Apparent ground-water 

ages ranged from as young as about 10 to 16 years in an alluvial 

drainage composed of unconsolidated material eroded from the 

adjacent Sandia Mountains to as old as about 20 to 26 years in 

fractured and solution-channeled limestone in the southern part 

of the study area. 

The range in ground-water age in consolidated rocks 

throughout the study area is about 16.5 to 23 years. This young 

age and the similarity in ground-water ages throughout the 

study area suggest that recharge occurs rapidly through 
24 Precipitation; Ground-Water Age; Nitrate Concentrations; 

fractured and solution-channeled limestone and that recently 

recharged ground water mixes with older water in the groundwater system along flow paths upgradient from the sampled 

wells. 

Concentrations of dissolved nitrate in samples from 24 

wells collected during 2001-02 were similar to concentrations 

in samples collected from the same wells during 1995, 1997, 

and (or) 1998. Nitrate concentrations in two wells were larger 

than the USEPA primary drinking-water regulation of 10 mg/L 

in 1998 and in 2001. The 2001 concentrations, however, were 

less than those in the previous samples collected during 1998. 

Ground-water levels were measured during June and July 

2002 and during June, July, and August 2003 in 18 monitoring 

wells. From 2002 to 2003, water levels rose in five wells; the 

rises ranged from 0.07 to 1.51 feet. Water levels declined in 13 

wells; the declines ranged from 1.11 to 17.66 feet. The median 

change in water level for all 18 wells was a decline of 2.03 feet. 

References 

Blanchard, P.J., 2003, Water quality and depth to water, 2001-

02, and graphs of selected constituents and depth to water, 

period of record through 2002, in selected wells, eastern Bernalillo County, New Mexico: U.S. Geological Survey OpenFile Report 03-81, 37 p. 

Blanchard, P.J., and Kues, G.E., 1999, Ground-water quality 

and susceptibility of ground water to effects from domestic 

wastewater disposal in eastern Bernalillo County, central 

New Mexico, 1990-91: U.S. Geological Survey WaterResources Investigations Report 99-4096, 109 p. 

and Levels in Eastern Bernalillo County, New Mexico 

Fishman, M.J., and Friedman, L.C., eds., 1989, Methods for the 

determination of inorganic substances in water and fluvial 

sediments: U.S. Geological Survey Techniques of WaterResources Investigations, book 5, chap. A1, 545 p. 

National Oceanic and Atmospheric Administration, 2002, 

Web climate services: National Oceanic and Atmospheric 

Administration data available on the Web, accessed 

January 15, 2003, at 

http://www.ncdc.noaa.gov/oa/climate/stationlocator.html . 

Plummer, L.N., and Busenberg, E., 1999, Chlorofluorocarbons, 

in Cook, Peter, and Herczeg, Andrew, eds., Environmental 

tracers in subsurface hydrology: Kluwer Academic Publishers, 552 p. 

Rankin, D.R., 2000, Water-quality and ground-water-level 

trends, 1990-99, and data collected from 1995 through 1999, 

east mountain area, Bernalillo County, central New Mexico: 

U.S. Geological Survey Open-File Report 00-476, 41 p. 

Titus, F.B., 1980, Ground water in the Sandia and northern 

Manzano Mountains, New Mexico: Socorro, New Mexico 

Bureau of Mines and Mineral Resources Hydrologic Report 

5, 66 p. 

U.S. Environmental Protection Agency, 2002, Current drinking 

water standards; National primary drinking water regulations: EPA 816-F-02-013, July 2002, 4 p. 

U.S. Geological Survey, 2003, The Reston Chlorofluorocarbon 

Laboratory: U.S. Geological Survey information available on 

the Web, accessed February 4, 2003, at 

http://water.usgs.gov/lab/cfc . 

Wilde, F.D., Radtke, D.B., Gibs, J., and Iwatsubo, R.T., eds., 

1998, National field manual for the collection of waterquality data: U.S. Geological Survey Techniques of WaterResources Investigations, book 9, chap. A4 and A5, 103 and 

128 p. 
Supplemental Data

Table 10. Monthly and annual precipitation at U.S. Geological Survey and volunteer precipitation sites, 2001-03. [ND, no data; bold values, more than 10 days of data missing] 

Year Jan Feb Mar Apr May June July Aug Sept Oct Nov 

Site 1: Sandia Mountains high altitude (start of data collection: 3/2/2001) 

2001 ND ND 1.79 0.97 0.00 0.00 0.19 3.73 0.51 0.28 1.79 2002 1.49 1.19 0.01 1.53 0.39 0.37 2.21 0.09 1.21 1.45 0.97 2003 0.22 0.80 1.34 0.70 0.30 0.37 ND 0.28 0.94 1.47 0.03 

Site 2: Sandia Mountains intermediate altitude (start of data collection: 3/1/2001) 

2001 ND ND 1.93 2.55 0.64 0.00 0.19 3.56 0.37 0.40 2.01 2002 1.89 0.77 0.00 0.80 0.23 0.11 2.61 1.77 0.37 0.22 0.92 2003 1.67 2.27 3.44 0.50 0.27 1.10 0.12 4.83 0.80 1.65 0.11 

Site 3: Sandia Mountains low altitude (start of data collection: 1/17/2001) 

2001 1.32 1.18 1.35 1.14 0.73 0.62 1.86 2.56 0.23 0.27 1.17 2002 1.01 0.00 0.10 0.36 0.43 0.03 2.32 0.92 2.07 0.85 0.90 2003 1.09 2.53 1.34 0.24 1.03 1.65 0.72 2.87 0.58 1.32 1.36 

Site 4: Manzanita Mountains high altitude (start of data collection: 3/1/2001) 

2001 ND ND 1.10 0.68 0.19 0.00 0.49 4.45 0.33 0.13 3.04 2002 2.45 0.00 0.10 0.00 0.01 0.00 0.00 0.00 0.00 0.00 0.00 2003 1.76 0.20 0.36 0.04 0.03 0.75 0.08 2.58 0.00 0.06 ND 

Site 5: Manzanita Mountains intermediate altitude (start of data collection: 1/25/2001) 

2001 1.02 1.11 1.57 0.88 0.34 0.00 0.04 1.36 0.27 0.15 2.94 2002 0.99 0.00 0.01 0.67 0.15 0.09 2.05 0.69 0.17 1.30 0.93 2003 0.19 0.09 0.08 0.01 0.00 0.04 0.09 2.26 1.01 1.16 1.04 

Site 6: Manzanita Mountains low altitude (start of data collection: 12/31/2000) 

2001 1.11 0.55 1.74 0.28 1.16 0.00 0.64 2.85 0.39 0.27 2.18 2002 0.32 0.26 0.29 0.31 0.06 0.00 0.01 0.00 0.00 1.90 0.36 2003 0.32 0.07 0.06 0.15 0.02 0.37 0.23 2.35 1.30 1.59 0.99 

Site 7: Tijeras, N. Mex. (start of data collection: 3/8/2001) 

2001 ND ND 0.88 0.95 0.67 1.30 3.18 2.46 0.49 0.21 1.56 2002 0.46 0.07 0.01 0.68 0.13 0.41 3.68 1.04 2.53 1.05 0.60 2003 0.01 1.81 0.97 0.19 0.26 1.02 0.44 2.46 0.84 0.79 1.27 
Table 11. Precipitation at Sandia Crest, in inches, 1953-79. [ND, no data; bold values, estimated precipitation] 

Year Jan Feb Mar Apr May June July Aug Sept Oct 

1953 ND ND ND ND ND ND ND ND ND ND 1954 2.00 0.36 2.37 0.05 2.19 1.45 3.05 1.48 1.37 1.04 1955 1.58 1.61 0.43 0.27 1.32 0.45 6.23 4.23 1.05 0.15 1956 2.39 1.80 Trace 0.35 0.18 0.47 4.47 1.96 0.07 1.40 1957 2.16 2.28 3.76 2.80 2.51 0.32 3.09 3.50 0.45 4.67 1958 2.13 1.18 6.55 3.21 0.38 0.02 0.49 2.67 4.56 3.03 1959 0.83 0.30 2.43 2.16 0.80 0.92 1.85 6.18 0.10 2.87 1960 3.15 2.43 2.18 0.50 1.22 1.60 1.06 1.46 0.94 4.79 1961 2.14 1.46 3.04 1.43 0.39 0.16 2.10 3.43 1.06 0.65 1962 1.59 1.88 1.59 0.30 0.05 0.34 3.85 1.42 2.60 1.41 1963 1.28 2.86 1.68 0.78 0.12 0.39 1.20 7.64 1.49 1.10 1964 0.62 2.64 1.14 1.28 2.52 0.00 5.37 2.15 1.90 0.33 1965 1.15 2.40 2.62 1.05 0.18 3.29 1.47 2.12 3.76 1.82 1966 0.88 1.39 0.25 0.01 0.56 3.88 3.37 2.65 1.18 0.05 1967 0.28 1.70 0.55 0.35 0.05 2.02 4.79 6.61 2.22 0.30 1968 0.65 2.83 4.24 2.73 1.25 0.24 4.70 5.70 0.71 0.23 1969 2.46 2.45 1.64 1.15 2.32 1.24 3.00 2.24 1.42 4.25 1970 0.17 1.19 3.47 1.38 0.24 1.10 3.92 3.73 1.89 1.14 1971 1.82 1.45 0.88 2.81 0.06 0.00 4.03 3.44 1.12 2.37 1972 1.52 0.40 0.56 0.06 1.19 1.09 1.91 3.36 3.12 5.79 1973 3.72 1.96 6.37 2.96 1.38 1.12 3.91 1.69 2.78 0.75 1974 4.10 1.52 1.61 0.17 0.33 0.06 3.13 3.70 2.55 5.09 1975 2.52 4.93 3.32 0.90 0.42 Trace 5.47 1.85 4.62 0.00 1976 0.37 1.49 2.29 1.24 1.30 0.61 3.38 3.68 0.91 0.12 1977 3.70 1.79 0.77 3.19 0.13 0.86 2.25 4.65 1.54 0.57 1978 3.70 3.93 4.79 0.77 1.92 2.00 1.73 3.53 2.07 1.71 1979 4.84 2.45 2.36 1.57 ND ND ND ND ND ND 
Table 12. Precipitation at Sandia Park, in inches, 1939-2001. [ND, no data; bold values, estimated precipitation; bold italicized values, incomplete data (missing 1 to 9 days of data)] 

Year Jan Feb Mar Apr May June July Aug Sept Oct 

1939 2.60 0.79 2.31 1.27 0.10 0.24 3.01 3.05 2.46 1.69 1940 1.29 2.60 2.06 0.73 1.69 0.57 0.48 2.72 1.66 0.72 1941 2.51 1.07 4.18 2.50 3.96 0.93 4.01 1.51 3.29 5.29 1942 0.35 ND ND ND 0.25 0.54 0.26 3.99 2.29 2.84 1943 0.81 ND ND ND ND ND ND 3.86 0.43 ND 1944 ND ND 1.72 1.27 0.30 0.43 3.54 3.07 1.43 1.18 1945 1.67 ND ND 1.92 0.00 0.30 2.54 3.24 1.05 1.27 1946 1.22 0.10 0.82 0.89 0.63 0.33 2.75 6.52 0.72 2.52 1947 0.41 0.39 0.37 0.42 1.04 0.45 1.30 3.89 0.60 0.70 1948 1.16 2.68 2.00 0.74 0.82 1.25 1.27 ND ND ND 1949 2.10 0.00 1.86 1.82 2.14 0.92 3.06 ND ND 0.36 1950 1.66 0.97 0.24 0.24 0.18 0.40 6.43 1.16 2.88 0.04 1951 1.56 0.44 0.96 0.44 0.48 0.03 3.10 3.67 0.05 0.73 1952 0.99 0.87 1.63 1.00 1.96 1.32 1.70 4.39 1.57 0.00 1953 0.42 1.13 1.70 1.33 0.87 3.04 1.43 1.81 Trace 0.87 1954 1.18 0.07 1.71 0.02 1.02 1.05 4.48 2.70 1.28 0.70 1955 0.68 1.02 0.07 0.37 1.16 0.46 3.78 4.46 2.37 0.14 1956 1.03 0.90 Trace 0.17 0.39 0.55 2.90 1.82 0.00 1.69 1957 1.45 1.71 2.22 0.95 1.61 0.11 4.36 4.42 0.17 2.81 1958 0.96 1.11 3.44 3.02 0.67 0.24 0.20 3.10 5.49 2.04 1959 0.35 ND ND 1.64 ND ND 2.12 4.10 ND ND 1960 ND ND ND ND 1.15 4.19 1.26 2.20 0.40 ND 1961 0.94 0.67 1.25 1.70 0.51 0.57 2.52 3.56 1.26 0.40 1962 0.78 1.44 0.76 0.11 0.24 0.97 6.18 0.95 1.90 1.11 1963 0.63 2.43 2.07 0.55 0.26 0.79 1.05 5.23 1.13 1.29 1964 0.69 2.62 0.46 1.61 2.27 Trace 3.64 2.36 1.67 0.31 1965 1.38 1.72 1.68 1.05 0.81 2.69 3.72 3.18 2.99 1.49 1966 1.32 0.36 0.05 0.11 0.79 1.86 4.07 1.76 1.16 0.42 1967 0.61 1.27 1.12 0.34 0.28 2.07 2.63 5.19 1.48 0.44 1968 0.08 2.40 3.31 1.39 1.04 0.11 3.40 4.34 0.13 0.39 1969 1.19 1.50 1.29 1.91 3.47 1.00 1.15 3.85 3.42 4.15 1970 0.09 0.39 1.82 0.58 0.05 0.85 3.93 2.37 1.34 2.07 
Table 12. Precipitation at Sandia Park, in inches, 1939-2001.—Continued [ND, no data; bold values, estimated precipitation; bold italicized values, incomplete data (missing 1 to 9 days of data)] 

Year Jan Feb Mar Apr May June July Aug Sept Oct 

1971 1.51 0.96 1.20 1.02 0.06 0.16 5.26 1.00 1.91 2.16 1972 0.32 0.41 0.05 0.00 2.84 0.58 1.47 4.27 2.83 5.57 1973 1.79 1.80 2.69 1.41 2.11 0.71 3.84 2.05 1.80 0.44 1974 2.75 0.40 1.16 0.30 0.12 0.04 3.18 3.09 1.73 4.32 1975 1.36 2.22 2.02 1.02 1.16 Trace 2.79 2.45 3.83 Trace 1976 0.02 0.70 0.64 0.35 0.90 0.84 3.19 2.01 1.19 0.36 1977 1.83 0.76 0.50 0.94 0.56 0.43 3.50 3.26 1.45 0.28 1978 2.14 1.60 2.81 0.21 2.98 1.51 1.43 2.60 1.76 1.40 1979 2.30 1.14 0.52 1.22 1.59 1.75 2.46 2.96 0.77 0.87 1980 2.18 1.92 1.08 0.59 0.70 0.11 0.54 1.55 3.26 1.38 1981 0.37 0.31 1.82 0.92 1.72 1.37 2.08 5.07 0.85 1.20 1982 1.09 1.89 2.16 0.53 0.98 0.26 1.65 3.73 4.05 1.64 1983 1.08 1.67 1.69 1.36 0.17 1.92 2.63 2.31 0.68 ND 1984 0.50 Trace 1.03 ND Trace 1.10 0.19 3.47 2.25 ND 1985 ND ND 3.61 2.93 1.60 0.94 2.14 1.34 3.03 2.94 1986 0.18 2.62 1.11 1.29 2.25 3.21 4.71 1.60 2.64 2.92 1987 2.11 2.03 0.62 1.54 2.16 1.82 1.64 2.69 0.38 0.84 1988 1.41 0.39 1.13 3.25 1.71 2.60 2.84 3.60 3.65 0.64 1989 1.60 0.80 1.39 0.12 0.10 0.13 6.08 1.51 1.00 1.44 1990 1.87 2.47 1.44 1.58 0.71 0.53 4.79 3.49 3.17 0.54 1991 1.17 1.30 1.72 Trace 1.50 1.86 7.40 6.03 2.65 0.86 1992 1.21 0.88 1.25 0.07 2.93 0.98 3.44 2.77 1.59 1.63 1993 3.87 1.78 1.37 0.06 1.22 0.26 3.13 3.42 0.59 2.19 1994 0.81 1.14 3.76 1.27 3.15 1.25 3.08 3.94 1.36 3.00 1995 2.88 1.11 1.24 1.34 0.86 0.92 1.68 3.66 1.36 0.00 1996 2.19 0.99 0.53 Trace 0.05 5.50 3.60 3.52 2.67 4.20 1997 2.86 ND ND ND ND ND ND 1.64 2.31 0.87 1998 0.35 1.50 1.56 1.05 0.00 0.31 5.05 1.68 0.94 3.33 1999 0.88 0.00 2.52 1.56 0.72 0.82 2.05 5.33 0.58 0.80 2000 0.89 0.51 3.70 0.51 0.06 0.87 2.95 2.71 0.02 4.13 2001 1.88 1.09 1.32 1.15 0.62 0.44 2.15 ND ND 0.20 
Table 13. Precipitation at the Sandia Ranger Station, in inches, 1933-74. [ND, no data; bold values, estimated precipitation] 

Year Jan Feb Mar Apr May June July Aug Sept Oct 

1933 0.19 0.03 0.32 1.07 1.21 2.45 2.79 3.77 2.20 0.77 1935 1.16 0.98 0.37 1.90 6.55 0.05 2.03 4.29 1.21 0.61 1937 0.27 0.27 1.64 0.67 4.32 1.50 0.64 0.90 1.78 1.10 1939 5.21 0.45 1.33 1.04 0.22 0.00 2.64 2.66 1.36 1.36 1940 1.17 1.66 1.64 0.71 1.61 0.82 1.49 4.30 2.04 0.84 1941 2.64 1.49 3.37 1.95 4.87 1.28 3.13 2.07 2.55 5.82 1942 0.57 0.90 0.63 4.85 0.00 1.15 0.81 1.83 2.10 1.96 1943 0.45 0.24 1.72 0.05 2.10 1.52 2.88 1.07 0.75 0.69 1944 0.94 0.71 1.40 1.87 0.71 0.98 4.52 1.99 1.19 0.69 1945 1.01 0.69 1.03 2.08 0.00 0.18 0.00 2.44 0.58 0.92 1946 0.94 0.19 1.35 0.49 0.29 0.10 2.75 3.14 0.68 1.19 1947 0.32 0.36 0.30 0.28 0.81 0.57 0.84 3.04 0.58 0.70 1948 0.86 1.89 1.42 0.54 ND 0.76 0.84 1.30 0.89 0.85 1949 1.56 0.44 0.98 2.22 1.24 0.28 4.59 1.97 1.44 0.26 1950 0.36 0.72 0.07 0.12 0.06 0.58 2.17 0.69 1.97 Trace 1951 1.24 0.33 0.50 0.81 0.36 0.15 2.27 3.00 0.00 0.31 1952 0.41 0.93 1.52 1.22 1.23 1.32 3.00 1.34 0.82 0.00 1953 Trace 0.62 1.18 0.91 0.39 1.81 1.75 2.42 0.12 0.78 1954 0.72 0.00 1.08 0.00 1.28 1.50 2.81 3.49 1.25 0.58 1955 0.36 0.38 0.00 0.08 0.94 0.36 4.01 3.80 1.38 0.15 1956 0.55 1.24 0.00 0.05 0.27 0.40 3.47 1.35 0.10 1.38 1957 0.98 1.48 2.02 1.03 0.98 0.05 2.52 3.05 0.06 2.51 1958 0.91 0.37 3.29 1.69 0.26 0.06 0.75 1.61 3.24 2.27 1959 0.10 0.12 1.12 1.00 0.48 0.25 1.45 1.98 0.38 2.39 1960 1.32 1.18 0.79 0.21 0.79 1.17 1.23 0.86 0.95 4.08 1961 0.82 0.56 1.03 1.54 0.56 0.23 2.33 2.79 1.13 0.21 1962 0.78 0.52 0.29 0.41 0.11 0.21 3.81 0.52 1.16 1.32 1963 0.29 1.91 0.99 0.37 0.20 0.24 1.01 4.59 1.65 0.89 1964 0.23 1.87 0.34 1.40 1.60 0.00 2.37 2.02 3.13 0.24 
Table 13. Precipitation at the Sandia Ranger Station, in inches, 1933-74.—Continued [ND, no data; bold values, estimated precipitation] 

Year Jan Feb Mar Apr May June July Aug Sept Oct 

1965 0.66 1.05 0.86 1.26 0.58 2.23 3.49 2.23 1.96 1.20 1966 0.92 0.46 0.00 0.13 0.24 3.25 3.02 3.26 0.65 0.00 1967 0.25 1.03 0.63 Trace 0.14 2.66 3.77 4.77 1.20 0.32 1968 0.00 1.75 2.19 1.07 0.66 0.10 1.21 3.18 0.25 0.29 1969 1.22 1.67 2.28 2.58 2.92 0.32 1.54 2.25 0.58 2.31 1970 0.25 0.30 1.58 0.30 0.11 1.05 3.49 1.42 0.85 1.05 1971 0.81 0.21 0.44 1.83 0.14 0.08 2.72 1.17 1.83 2.24 1972 0.03 0.18 0.16 0.00 1.02 0.84 0.62 2.27 3.63 4.28 1973 1.86 1.19 2.44 1.59 1.71 0.71 3.72 1.32 1.86 0.72 1974 1.74 0.19 0.89 0.33 0.00 0.06 1.38 2.79 1.87 4.90 
Table 14. Snowfall at Sandia Crest, in inches, 1953-79. [ND, no data] 

Year Jan Feb Mar Apr May June July Aug Sept Oct 

1953 ND ND ND ND ND ND ND ND ND ND 1954 17.5 2.0 9.8 0.0 4.5 0.0 0.0 0.0 0.0 0.0 1955 20.8 23.8 4.0 1.1 5.0 0.0 1.0 0.0 0.0 0.0 1956 19.9 25.3 Trace 3.5 0.0 0.0 0.0 0.0 0.0 4.5 1957 17.5 16.0 33.0 20.0 2.5 0.0 0.0 0.0 0.0 10.5 1958 29.1 18.5 67.9 34.5 0.8 0.0 0.0 0.0 0.0 5.0 1959 9.5 3.8 22.8 10.5 0.5 0.0 0.0 0.0 0.0 15.5 1960 40.5 32.0 22.5 4.0 5.5 0.0 0.0 0.0 0.0 24.0 1961 16.0 24.5 32.5 13.0 1.0 0.0 0.0 0.0 1.0 2.0 1962 28.5 15.5 22.0 3.0 0.0 0.0 0.0 0.0 0.0 0.5 1963 13.5 24.0 18.0 5.0 Trace 0.5 0.0 0.0 0.0 Trace 1964 10.5 60.3 16.5 18.5 7.5 0.0 0.0 0.0 0.0 0.0 1965 16.1 35.8 25.5 11.5 Trace 1.0 0.0 0.0 0.3 10.0 1966 14.3 17.5 6.0 0.1 Trace 0.0 0.0 0.0 0.0 0.1 1967 2.5 21.0 6.6 2.5 Trace 0.0 0.0 0.0 0.0 1.3 1968 9.0 34.0 47.0 18.0 8.0 0.0 0.0 0.0 0.0 0.0 1969 10.7 22.3 39.1 9.5 17.3 0.0 0.0 0.0 0.0 15.5 1970 1.9 16.0 31.7 11.5 Trace Trace 0.0 0.0 0.0 3.0 1971 19.5 27.1 15.0 17.8 3.5 0.0 0.0 0.0 1.5 6.5 1972 16.0 4.0 1.5 0.6 4.0 0.0 0.0 0.0 0.0 11.8 1973 32.5 20.0 57.6 33.5 6.5 0.0 0.0 0.0 0.0 6.5 1974 30.8 19.5 17.3 1.3 2.0 Trace 0.0 0.0 0.0 12.5 1975 27.5 43.0 22.0 9.0 1.0 0.0 0.0 0.0 0.0 0.0 1976 4.0 9.0 15.3 9.5 ND 0.0 0.0 0.0 0.0 ND 1977 30.0 14.5 15.3 24.0 0.0 0.0 0.0 0.0 0.0 0.0 1978 ND ND 32.8 4.3 21.3 0.0 0.0 0.0 0.0 2.2 1979 45.8 27.5 13.2 11.3 ND ND ND ND ND ND 
Table 15. Snowfall at Sandia Park, in inches, 1939-2001. [ND, no data; bold italicized values, incomplete data (missing 1 to 9 days of data)] 

Year Jan Feb Mar Apr May June July Aug Sept Oct 

1939 35.5 22.8 7 2 0 0 0 0 0 0 1940 13 26 12 5 0 0 0 0 0 2.5 1941 25 4 35.5 6 0 0 0 0 0 Trace 1942 3 ND ND ND 0 0 0 0 0 ND 1943 5 ND ND ND ND ND ND 0 0 ND 1944 ND ND 12 5 0 0 0 0 0 0 1945 10 ND ND 7 0 0 0 0 2 Trace 1946 17.5 2 4 0 0 0 0 0 0 0 1947 10.5 3.5 5 5.5 0 0 0 0 0 0 1948 ND ND ND ND ND 0 0 ND ND ND 1948 16 32.5 21 2 0 ND ND ND ND ND 1949 32.8 ND 14 21 0 0 Trace ND ND ND 1950 5 10.5 1.5 ND 0 0 0 Trace Trace 0 1951 22 1.5 7.5 1.8 Trace 0 0 0 0 0 1952 2.5 5 15 1 3 0 0 0 Trace 0 1953 6 18.5 6.8 Trace ND Trace 0 Trace 0 0 1954 15 1 2.5 0 Trace 0 Trace Trace 0 0 1955 12 7 1 0 Trace 0 0 0 Trace 0 1956 7.5 19 Trace 2 Trace 0 0 0 0 Trace 1957 9 4 4.5 6 Trace 0 0 0 0 Trace 1958 19.3 7.5 35 24.5 0 0 0 0 0 3 1959 ND ND ND ND ND ND 0 0 ND ND 1960 ND ND ND ND 0 0 0 0 0 ND 1961 ND ND ND ND Trace 0 0 0 0 0 1962 5.8 4 3.5 0 Trace 0 0 0 0 0 1963 10 10.5 9.5 Trace 0 0 0 0 0 0 1964 5.5 26.5 ND ND 0 0 0 0 0 0 1965 1 12 5 Trace 0 0 0 0 0 Trace 1966 13 3 1.5 0.5 0 0 0 0 0 Trace 1967 ND ND ND ND 0 0 0 0 0 Trace 1968 1 22 40 5 0 0 0 0 0 0 1969 ND 10.5 ND ND 2 0 0 0 0 ND 
Table 15. Snowfall at Sandia Park, in inches, 1939-2001.—Continued [ND, no data; bold italicized values, incomplete data (missing 1 to 9 days of data)] 

Year Jan Feb Mar Apr May June July Aug Sept Oct 

1970 ND 6 ND ND 0 0 0 0 0 3.6 1971 21 11 12.8 ND 0 0 0 0 0.8 Trace 1972 5.7 5.3 Trace 0 0 0 0 0 0 3 1973 35.9 16.6 33.2 18.6 0.6 0 0 0 0 0.5 1974 21.6 7.4 10.8 0.5 0 Trace 0 0 0 ND 1975 19.8 24.4 10.7 8 0 0 0 0 0 0 1976 0.9 0.4 8.5 Trace 1.6 0 0 0 0 1.1 1977 23.5 11 3.5 3.1 0 0 0 0 0 0 1978 ND 19.5 11.7 1.5 14.4 0 0 0 0 0.6 1979 ND 21.5 1.5 5.6 Trace 0 0 0 0 ND 1980 14.7 8.2 5.3 6.3 0 0 0 0 0 7.5 1981 3.7 4.5 11.3 0 0 0 0 0 0 0 1982 11.9 19.8 5.7 1 Trace 0 0 0 0 6.1 1983 13.8 18.9 13 20.1 Trace 0 0 0 0 ND 1984 8.2 Trace 13 15.4 0 0 0 0 0 ND 1985 ND ND 11 2 0 0 0 0 0 0 1986 2 30 10 3 1 0 0 0 0 12 1987 43 32 10 12 0 0 0 0 0 0 1988 12 3 13.5 12 0 0 0 0 0 0 1989 17 7 10 Trace 0 0 0 0 0 0 1990 22 26 6 1 3 0 0 0 0 0 1991 4.5 3 7.5 Trace 0 0 0 0 0 6 1992 14 2 2.5 0 0 0 0 0 0 0 1993 11.5 14 9 Trace 0 0 0 0 0 2 1994 11 5 26 6 0 0 0 0 0 1 1995 27 0 5 14 0.5 0 0 0 0 0 1996 19 9 5 Trace Trace 0 0 0 0 20 1997 32 ND ND ND ND ND ND 0 0 0 1998 2.8 6 10.9 1 0 0 0 0 0 0 1999 4 0 26 4 0 0 0 0 0 8 2000 3.7 5 26.5 6 0 0 0 0 0 0 2001 27.2 8 6.5 4 0 0 0 ND 0 0 
Table 16. Snowfall at the Sandia Ranger Station, in inches, 1933-74. [ND, no data] 

Year Jan Feb Mar Apr May June July Aug Sept Oct 

1933 2.6 ND ND 7.0 8.0 0.0 0.0 0.0 0.0 0.0 1934 4.0 1.0 Trace 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1935 3.0 7.0 Trace 4.0 18.0 0.0 0.0 0.0 1.0 Trace 1936 3.0 5.5 1.7 1.0 0.0 0.0 0.0 0.0 6.5 0.0 1937 5.5 1.0 10.5 8.0 0.0 0.0 0.0 0.0 0.0 0.0 1938 5.0 10.0 1.2 7.0 0.0 0.0 0.0 0.0 0.0 0.0 1939 15.0 17.0 2.0 3.0 0.0 0.0 0.0 0.0 0.0 0.0 1940 8.5 8.8 9.0 1.5 0.0 0.0 0.0 0.0 0.0 0.0 1941 9.1 1.0 18.6 0.5 0.0 0.0 0.0 0.0 0.0 Trace 1942 8.2 8.0 5.2 Trace 0.0 0.0 0.0 0.0 0.0 0.0 1943 4.7 1.7 Trace 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1944 12.8 2.1 9.8 12.0 Trace Trace 0.0 0.0 0.0 0.0 1945 9.1 7.0 0.5 6.0 0.0 0.0 ND 0.0 Trace 0.0 1946 23.4 6.5 12.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1947 5.0 Trace 0.5 Trace 0.0 0.0 0.0 0.0 0.0 0.0 1948 19.4 24.0 11.2 0.0 ND ND ND ND ND ND 1948 ND ND ND ND ND 0.0 0.0 0.0 0.0 0.0 1949 23.7 7.1 9.5 10.0 0.0 0.0 0.0 0.0 0.0 0.0 1950 6.1 6.0 Trace Trace 0.0 0.0 0.0 0.0 0.0 0.0 1951 ND 0.9 Trace 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1952 1.0 ND ND 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1953 0.0 ND ND 0.0 Trace 0.0 0.0 0.0 0.0 0.0 1954 7.5 0.0 0.0 0.0 Trace Trace 0.0 0.0 0.0 0.0 1955 5.0 2.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1956 1.0 9.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1957 ND 0.0 0.0 ND 0.0 0.0 0.0 0.0 0.0 0.0 1958 ND 0.0 ND ND 0.0 0.0 0.0 0.0 0.0 0.0 1959 ND ND ND 0.0 0.0 0.0 0.0 0.0 0.0 ND 1960 ND ND ND 0.0 0.0 0.0 0.0 0.0 0.0 0.0 
Table 16. Snowfall at the Sandia Ranger Station, in inches, 1933-74.—Continued [ND, no data] 

Year Jan Feb Mar Apr May June July Aug Sept Oct 

1961 ND ND ND 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1962 ND ND ND 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1963 2.5 ND ND 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1964 2.5 ND ND ND 0.0 0.0 0.0 0.0 0.0 0.0 1965 ND ND ND 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1966 ND Trace 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1967 0.0 ND ND Trace 0.0 0.0 0.0 0.0 0.0 0.0 1968 0.0 ND ND 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1969 0.0 ND ND ND 0.0 0.0 0.0 0.0 0.0 0.0 1970 0.8 3.0 13.5 0.0 0.0 0.0 0.0 0.0 0.0 ND 1971 7.5 3.1 5.8 Trace 0.0 0.0 0.0 0.0 ND 0.0 1972 0.3 0.2 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Trace 1973 17.0 6.0 ND 16.0 0.0 0.0 0.0 0.0 0.0 0.0 1974 ND ND 0.6 0.0 0.0 0.0 0.0 0.0 0.0 0.0 
For more information concerning the research in this report, contact: 

Linda Weiss, District Chief 

U.S. Geological Survey 

5338 Montgomery Blvd, NE 

Suite 400 

Albuquerque, NM 87109 

or visit our Web site at: 

http://nm.water.usgs.gov 
Blanchard, Paul J.—Precipitation; Ground-Water Age; Ground-Water Nitrate Concentrations, 1995-2002; and Ground-Water Levels, 2002-03 in Eastern Bernalillo County, New Mexico—Scientific Investigations Report 2004-5189