Ammoniated Thermal 

Waters of Lake and 

Colusa Counties 

California

GEOLOGICAL SURVEY WATER-SUPPLY PAPER 1535-A
\mmoniated Thermal 

Waters of Lake and 

Golusa Counties 

California

'y C. E. ROBERSON and H. C. WHITEHEAD

GEOCHEMISTRY OF WATER

GEOLOGICAL SURVEY WATER-SUPPLY PAPER 1535-A

JNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1961
UNITED STATES DEPARTMENT OF THE INTERIOR 

STEWART L. UDALL, Secretary

GEOLOGICAL SURVEY 

Thomas B. Nolan, Director

For sale by the Superintendent of Documents, U.S. Government Printing Office 

Washington 25, D.C. - Price £5 cents
CONTENTS

	Page

Abstract____________________________________ _________ ___________ A-1

Introduction. _______________________________________________ 1

Thermal springs______________________________________________ 2

Sulphur Bank mine area______________________________________ 2

Wilbur Springs-Elgin mine area____________________-___-__-_-__- 6

Analytical problems in nitrogen determination ________________________ 9

References______________________________________________________ 11

ILLUSTRATIONS

FIGTTBE 1. Map of part of California showing location of Sulphur Bank

and Wilbur Springs-Elgin mine________________________ A-2

2. Graph showing change in ammonia nitrogen as NH4+1 during

storage of a water sample_____________________-_________ 5

3. Map of Wilbur Springs-Elgin mine area showing location of

water-sample points-__________________________________ 7

TABLES

TABLE 1. Partial chemical analyses of water from the Sulphur Bank area. A-3 

2. Partial chemical analyses of water from the Wilbur Spring-Elgin

mine area____________________________________________ 8

in

GEOCHEMISTRY OF WATER

AMMONIATED THERMAL WATERS OF LAKE AND 

COLUSA COUNTIES, CALIFORNIA

By C. E. KOBEKSON and H. C. WHITEHEAD

ABSTRACT

Thermal springs in two areas north of San Francisco, Calif., contain nitrogen 

occurring as ammonia, nitrite, and nitrate. The nitrogen compounds show, in 

general, progressive oxidation with increasing distance downchannel from spring 

orifices, and with exposure to air during storage of water samples. The resulting 

increase in content of nitrite and nitrate is accompanied by a decrease in bicarbonate. Oxidation of sulfides when they are present also occurs.

INTRODUCTION

Thermal springs in an area centered about 90 miles north of San 

Francisco, Calif, (fig. 1), are noted, among other things, for their 

high concentration of combined nitrogen. The general character of 

much of the spring water from that area has been discussed by D. 

E. White (1957). Studies of the unusual waters in the Sulphur 

Bank and Wilbur Springs areas, Lake and Colusa Counties, may 

solve some of the unanswered problems of nitrogen chemistry.

Data used in this paper are from analyses of samples collected 

by White and a series of samples collected by the authors in the fall 

of 1958, especially for a study of the behavior of combined nitrogen 

in these particular waters. All samples were analyzed by the U.S. 

Geological Survey in the laboratory at Menlo Park, Calif.

The results show that in some of these springs the nitrogen occurs 

at the orifice as ammonia. 1 However, oxidation occurs progressively 

downstream in runoff channels, and the nitrogen is present in the 

water both as nitrite and as nitrate. Furthermore, the results indicate with few exceptions, that nitrogen in water samples from springs 

with a high combined nitrogen content shows progressive oxidation 

with time of contact of the water with the air. Thus, if a sample is 

exposed to air and stored in the laboratory, the concentration of 

ammonia progressively decreases and the concentration of nitrite and, 

(or) nitrate tends to increase. The progress of this oxidation is 

mediated in a large part, presumably, by bacteria.

1 The terms "ammonia" and "ammonia nitrogen as NH4+1" used in the text 

and in tables 1 and 2, respectively, refer to nitrogen in the form of NHs^NH**1 . 

These forms of nitrogen occur in these waters primarily as ammonium (NEU+1)'

A-l
A-2 GEOCHEMISTRY OF WATER

Wilbur Springsciear\ Elgin mine area

Lak

124" 123° 12i°

FIOUEE 1. Map of part of California showing location of Sulphur Bank and Wilbur Springs-Elgin min

THERMAL SPRINGS

Thermal springs in two areas (fig. 1) furnished the water samples 

discussed in the present study. These areas are the Sulphur Bank 

mine area, located on the shore of Clear Lake, and the Wilbur Springs 

area, about 15 miles east of Sulphur Bank.

SULPHUR BANE MINE AREA

The Sulphur Bank mine is on the southeast edge of the east arm 

of Clear Lake. The mine was first worked for sulfur, and later it 

became one of the largest producers of quicksilver in the United 

States (White, 1955; 1957). Outcrops near Sulphur Bank consist 

mainly of sedimentary rocks of Jurassic (?) age overlain near the mine 

by Quaternary lake sediments and altered pyroxene andesite (White, 

1955, p. 117). Water samples (table 1, Nos. 180, 181) of two of the
TABLE 1. Partial chemical analyses of water from the S

Sample

108

180 

181 

834 

835 

836 

838 

839 

840

Source of water

Sulphur Bank, spring on north 

wall.

Thermal spring, southwest wallCold acid spring, southwest 

waU.s 

Mixture of 834 and 835 ..........

Bubbling thermal spring, north 

wall.

Date

Collection

10-56

3-26-57 

3-26-57 

9-17-58 

9-17-58 

9-17-58 

9-17-58 

9-17-58 

9-17-58

Analysis

4-23-57 

2- 7-57 

3-8-57 

3-11-57 

3-14-57 

7-18-57 

7-18-57 

9-30-58 

9-30-58 

9-30-58 

9-30-58 

9-30-58 

9-30-58

Temperature at 

time of 

collection 

(°F)

156 

170 

105 

60 

(4) 

128 

95 

79

Upper number, parts 

Lower number, equivale

Ammonia 

nitrogen 

as 

(NH4«)

276 

15.30 

230 

12.75 

223 

12.36 

209 

11.58 

464 

25.72 

476 

26.38 

59 

3.27 

13 

.72 

60 

3.33 

460 

25.50 

430 

23.83 

485 

26.88

Nitrate 

(NOr1)

470 

10.22

.00 

.00 

.00 

.00 

.07 

.00 

.00 

.00 

.16 

.00 

.00 

.00 

1.5 

.03 

5.6 

.12

Nitrite 

(NOri)

0.0 

.00

.0 

.00 

.0 

.00 

4.0 

.06 

24 

.34 

4.0 

.06 

2.0 

.03 

2.0 

.03 

6.0 

.10

Bic

bon

(HCO

12,59

14

3,29

5

2,96

4

1,47

2

1,48

2

4,06

6

4,02

6

4,03

6

i Determined 3-11-57.

* Qualitative test; results negative.

* Flow contributio

< Warm.
A-4 GEOCHEMISTRY OF WATER

springs discharging from the north wall of Hermann pit at Sulphur 

.Bank were analyzed in July 1957. These waters are representative 

of the mineralized springs in the area.

Sample 108, collected in October 1956 from a spring on the north 

side of the pit at Sulphur Bank, was analyzed 4 times for ammonia 

in a period of 35 days, early in 1957. It was found that the ammonia 

content had dropped from 276 ppm (parts per million) to 209 ppm 

over a period of 35 days (fig. 2).

Another determination for nitrite made on water from the same 

source, but taken from a small bottle which was only about one-fourth 

full and which had been opened several times during the course of 

analysis, contained 880 ppm nitrite. Thus this sample, which had 

been repeatedly exposed to the air, had the greater opportunity for 

obtaining the oxygen needed for oxidation; hence, the more rapid 

change of ammonia to nitrite.

The nitrate found in the sample was less than 10 ppm. A more 

specific value cannot be assigned because in the determination of 

nitrate, the nitrate and nitrite are reduced together and distilled as 

ammonia. The total so obtained is corrected by using a separate 

method to determine the amount of nitrite. Because the determination of nitrite is very sensitive, small samples of water are used when 

the concentration of nitrite is high and any error in the determination, 

however small, is magnified by the computation factor. And because 

the value for nitrate is obtained by difference, a small percentage 

error in the determination of nitrite would introduce a much larger 

percentage error for nitrate when these constituents are present in 

high and low concentrations, respectively. However, the nitrate 

content of the samples mentioned above is relatively low, indicating 

that nitrite was not being rapidly oxidized to nitrate.

Two series of samples (834-836 and 838-840) in the Sulphur Bank 

area contained high concentrations of ammonia that exhibited 

various degrees of stability. These samples were collected in the 

fall of 1958. The amount of nitrite was determined in the field 

immediately upon sampling, and samples preserved with formaldehyde 

were brought back to the laboratory for further study of the nitrogen 

compounds.2 The nitrite content of the preserved samples was 

again determined after return to the laboratory, and the laboratory 

values are reported in the tables. These values confirm the results 

obtained in the field within the sensitivity limits of the field procedure.

A thermal spring on the southwest wall of Hermann pit (834) had 

one of the lowest values for ammonia obtained in this area. Hydrogen 

sulfide was conspicuously absent. The sulfate content, notably

* The amount of ammonia was determined by distillation as NHs and titration with acid. The Griess 

reaction was used for determining the amount of NOs~l both in the field and in the laboratory.
AMMONIATED THERMAL WATERS OF LAKE AND COLUSA COUNTIES A~5

\ \

\

\ \

\ \

\ \ \ \ \

\ \

\

\

\

\

-\ 

\ \ \*

10 20 30 

TIME OF STORAGE. IN DAYS

40 .50

FIOTJEE 2. Graph showing change in ammonia nitrogen as NH4+1 during storage of a water sample. Sample 

from a thermal spring at Sulphur Bank (table 1, No. 108).
A-6 GEOCHEMISTRY OF WATER

greater than that of the other thermal springs sampled at Sulphur 

Bank by the authors, suggests that any hydrogen sulfide present at 

depth must be oxidized to sulfate during passage of the water toward 

the earth's surface. This change suggests a loss of the reducing 

environment that seems prevalent at many other springs in the area. 

The ammonia, characteristic of water from nearby springs, has 

presumably been partly lost. There seems to be no concurrent rise 

in the oxidized forms of nitrogen.

The decrease in ammonia content of water at higher rates than the 

increase in nitrite and nitrate is a well-known phenomenon (Hutchinson, 1957, p. 864). Presumably nitrogen is lost as nitrogen gas 

or ammonia gas and by metabolic processes in which nitrate is 

assimilated.

In another thermal spring, on the north wall of Hermann pit (838) 

about 100 yards down the road leading into the pit, there was considerable bubbling in the spring pool caused by gas evolution and the 

odor of hydrogen sulfide was easily detected. The ammonia content 

in a sample from the center of the bubbling water was found to be 

high (460 ppm), but very little nitrate and no nitrite were present. 

The spring water flowed 2 or 3 feet away into a small depression in 

the road and was ponded. A sample from this small pool (839) had 

lower concentrations of ammonia and hydrogen sulfide and higher 

concentrations of chloride, sulfate, and nitrite than the sample from 

the spring.

The overflow from the standing pool (840) was sampled 20 feet 

farther down the slope and found to contain more nitrite. No hydrogen sulfide was noticed and the sulfate content was greater. The 

lower concentrations of ammonia and nitrite found in the samples 

collected from both the bubbling and the standing pools may result 

from lack of mixing in these pools.

WILBUR SPRINGS-ELGIN MINE AREA

The Wilbur Springs-Elgin mine area (fig. 3) is in the valley of Sulphur Creek in southwestern Colusa County, Calif., about 15 miles 

east of the Sulphur Bank area. The springs at the Elgin mine at 

the time of the investigation constituted virtually the entire flow of 

the headwaters of Sulphur Creek. The creek flows past Wilbur 

Springs and joins Bear Creek 1 mile below Wilbur Springs.

Both the springs in and the surface waters draining the Wilbur 

Springs-Elgin mine area were sampled to show changes in combined 

nitrogen. Sampling points are shown on figure 3 and analyses on
AMMONIATED THERMAL WATERS OF LAKE AND COLUSA COUNTIES A-7

table 2. A thermal spring (845) at the Elgin mine had a high content of ammonia, of sulfide as H2S, and of bicarbonate. No nitrite 

was found in this water and there was only 2 ppm of nitrate. Sulphur 

Creek was sampled about a mile down the hillside from the Elgin 

mine (846). The stream at this point was receiving most of its flow 

from the springs at the Elgin mine. The analysis, however, especially 

values for hardness and sulfate, implied mixing of water from the 

creek with water of undetermined chemical quality from other 

sources.

The water from the stream contained considerably less ammonia 

(68 ppm) than that from the Elgin mine (271 ppm). Similarly, the 

bicarbonate concentration was lower, sulfide was absent, and the 

sulfate concentration (648 ppm) was much greater. The nitrite content (55 ppm) was high, compared to none found for the spring at 

the Elgin mine. The nitrate content (15 ppm) was also greater than 

in the sample from the mine.

In terms of nitrogen (N), the thermal spring (845), at its source 

had 210 ppm of nitrogen (N) occurring predominantly as NH*1 ^ 

whereas the runoff (846) had only about 73 ppm of nitrogen (N) 

occurring as NH^1 , NO^ 1 , and

FIGURE 3. Map of Wilbur Springs-Elgin mine area showing location of water-sample points. Numbers, 

refer to analyses reported in table 2.
TABLE 2. Partial chemical analyses of waters from the Wilbur 

Sample

845. . 

846. 

844. 

842 

841, 

Source of water

Elgin mine, Judge Moore 

tunnel (?). 

Sulphur Creek, 1 mile 

downstream from 845. 

Sulphur Creek above 

Wilbur Springs.

Sulphur Creek 0.4 mile 

below Wilbur Springs.

Date

Collection

9/18/58 

9/18/58 

9/18/58 

9/18/58 

9/18/58

Analysis

9/30/58 

9/30/58 

9/30/58 

9/30/58 

9/30/58

Temperature 

(°F)

148 

80 

72 

121 

65

Upper number, parts per mill

Lower number, equivalents per m

Ammonia 

nitrogen 

as NH4+1

271 

15.02 

68 

3.77 

3.9 

.22 

266 

14.74 

80 

4.43

Nitrite 

(N0,-i)

0.00 

.00 

55 

1.20 

0.10 

.00 

.00 

.00 

.91 

.02

Nitrate 

(NOs-i)

2.0 

.03 

15 

.24 

1.6 

.03 

2.0 

.03 

2.1 

.03

Bicarbonate 

(HCOs-i)

7,320 

119. 97 

J3.790 

i 62. 12 

1,520 

24.91 

6,910 

113. 25 

3 4,640 

76.05

S

(

i C03 : 991 ppm, 33.03 epm.

8 Qualitative test; results negative.

» COs: 185 ppm, 6.17 
AMMONIATED THERMAL WATERS OF LAKE AND COLUSA COUNTIES A~9

Sulphur Creek was sampled farther downstream, about a mile above 

Wilbur Springs (844). The creek at this point seems to have been 

diluted fourfold, as shown by a decrease in the chloride content from 

11,200 ppm to 2,990 ppm. Although a fourfold dilution would normally yield 50 ppm of nitrogen, only 3 ppm were found.

The Wilbur Springs sample (842) had the highest amount of ammonia, sulfide, and bicarbonate. Here, Sulphur Creek was receiving 

one-fourth to one-half of its flow from the springs. About 0.4 mile 

below Wilbur Springs, the creek water (841) had a lower content of 

ammonia and bicarbonate, and no sulfide was present.

ANALYTICAL PROBLEMS IN NITROGEN DETERMINATION

In all cases cited there has been an oxidation of ammonia, an oxidation of sulfide, a loss of bicarbonate, and a gain in nitrite and (or) 

nitrate. The mechanism of the oxidation of ammonia to nitrite and 

finally to nitrate has been discussed by Cooper (1937, p. 183-204) and 

others. From the equation

NH4+1 +OH- 1 +3/2 O2 »H+1 +NO2- 1 +2H2O

three principal conditions are necessary: (a) A positive oxidation 

potential (that is, a loss of reducing conditions); (b) an external source 

of oxygen, whether from dissolved oxygen, atmospheric oxygen, or release of combined oxygen by bacterial or other action; and (c) a production of hydrogen ions from the oxidation process. The hydrogen 

ions then react with, and decrease the content of, bicarbonate and (or) 

carbonate. W. L. Lamar (oral communication, 1958) has studied the 

decrease of bicarbonate during the oxidation of ammonia. This decrease is due to the reaction of the produced hydrogen ions with the 

bicarbonate to liberate carbon dioxide gas.

In some environments the nitrite ion is reduced by sulfide to ammonia; hence, no nitrite will be found where sulfides are present 

(Rider and Mellon, 1946, p. 969). In other sulfide environments 

oxidized forms of nitrogen do not occur. White (1957) believes that 

some of the water is connate; hence, these waters indicate an 

anaerobic environment brought about by the decomposition of organic matter in deeply buried sedimentary rocks. However, upon 

exposure to air in runoff channels, the reducing environment, which is 

characteristic of such waters, changes, and oxidized species such as 

nitrite, nitrate, and sulfate appear. The relationship between the 

presence of sulfide and the absence of nitrite is shown in tables 1 and 2.

W. L. Lamar (written communication, 1956) reported on the 

changes in nitrogen compounds and bicarbonate of water samples in 

storage. He showed that, where oxygen is available, there was a pro-
A-10 GEOCHEMISTRY OF WATER

gressive loss of ammonia and of bicarbonate and a progressive increase of nitrite and (or) nitrate.

The results reported hi this paper generally confirm the observations 

of Lamar. Any discrepancies were probably due to the different 

chemical histories of the waters sampled. Important variables in 

these histories are (a) release of pressure as water emerges, (b) reduction of temperature, and (c) exposure to oxygen, bacteria, and algae 

in runoff channels. In most cases the loss of ammonia is far greater 

than any observed gain in oxidized nitrogen.

A laboratory example of the loss of nitrogen in water containing 

ammonia is shown by a water sample collected at the Abbot quicksilver mine. This mine is in Lake County, 2 miles southwest of 

Wilbur Springs (fig. 3). The water was pumped from the mine and 

collected on March 27, 1957. A qualitative test in the field indicated 

nitrite was present at the tune of collection. The ammonia, nitrite, 

and nitrate were determined both 3 weeks and 17 months after collection. The sample was stored in a stoppered gallon bottle onethird full. The following results, hi parts per million, indicate that 

about 19 ppm of nitrogen was lost during storage.

S weeks 17 months

Amount of Calculated Amount of Calculated

constituent as N constituent as N

NH4+1 -______--_---_--____.___ 22 17 0.1 0.1

NOr1 ------------------------ 14 4.3 .0 .0

NO*- 1 -.--.-. __________________ 4 .9 13 2.9

Total______________ _____. 22.2 _____ 3.0

Some nitrogen is probably lost by the escape of ammonia gas. 

Hutchinson (1957, p. 850) states that at near-neutral pH values the 

ammonia is largely present as dissociated ammonium ions (NH^"1 ) 

with only a small part present as undissociated NH4OH as follows: 

at pH 6.0 the ratio NHJYNH4OH is about 3000:1, at pH 7.0 about 

300:1, and at pH 8.0 about 30:1. At a pH of 9.5 the concentration 

of NHJ1 and NH4OH are approximately equal.

Assuming that these ratios apply to the conditions prevailing in 

the spring areas considered hi the present paper, the loss due to the 

evolution of ammonia gas might be small at near-neutral pH values. 

In runoff channels downstream from the orifices of springs, however, 

the pH increases, as was observed hi the runoff channels under study. 

The ratio NH^/NE^OH decreases and the loss of ammonia gas may 

be appreciable. Another factor that may cause a large loss of nitrogen 

is organic activity utilizing the nitrogen present as nitrite and nitrate.

Analytical problems connected with determinations of nitrogen 

suggest that samples should be analyzed for nitrogen components as 

soon as possible after collection, preferably in the field. As this is
AMM01STIATED THERMAL WATERS OF LAKE AND COLUSA COUNTIES A-l 1

usually difficult, especially with ammonia, the sample should be 

treated with chloroform or formaldehyde to inhibit bacterial action. 

Acidification of the sample to a pH of about 4 would tend to preserve 

the ammonia. For water having a pH greater than 6 this would 

seem especially desirable in order to inhibit loss of nitrogen as ammonia 

gas. A combination of an acid and an inhibitor of bacterial action, 

such as formaldehyde or chloroform, would probably prevent both 

the change of oxidation state of the nitrogen compounds and the loss 

due to evolution of ammonia gas. However, preservatives probably 

should not be relied upon to inhibit oxidation of the nitrogen for 

extended periods.

There is a need for definite knowledge of the changes undergone 

by the various forms of nitrogen in order to explain the unequal rise 

and fall in the quantity of ammonia versus nitrite and nitrate. The 

method of oxidation, whether biological and (or) chemical of the 

ammonia, and the source of oxygen, all need further investigation.

REFERENCES

Cooper, L. H. N., 1937, The nitrogen cycle in the sea: Jour. Marine Biology

Assoc., United Kingdom, v. 22, p. 183-204. 

Hutchinson, G. E., 1957, A treatise on limnology: New York, John Wiley &

Sons, Inc., v. 1, 1015 p. 

Rider, B. V., and Mellon, M. G., 1946, Colorimetric determination of nitrites:

Anal. Chemistry, v. 18, p. 96-99. 

White, D. E., 1955, Thermal springs and epithermal ore deposits in Pt. 1 of

Economic Geology, 50th anniversary volume, 1905-55: Urbana, 111., Econ.

Geol. Pub. Co., p. 99-154. 

 1957, Magmatic, connate, and metamorphic waters: Geol. Soc. America

Bull., v. 68, p. 1659-1682.

U.S. GOVERNMENT PRINTING OFFICE: 1961