Ill, FLUORIDE EMISSION CONTROL TECHNOLOGY

The most effective method for removing fluoride from stack discharge is by
the use of liquid scrubbers. Hundreds of scrubbers are operating for this purpose
throughout the country. Efficiency of collection depends upon factors such as
design features, pressure drop, scrubbing medium, and temperature as well as on
proper maintenance and attention to operation.

Corrosion of metallic surfaces and plugging of sprays and packing are ser-
jous operating problems that must be considered in the design of equipment. Some
method of removing the fluoride from the scrubbing liquid must be provided if a
recirculating system is used. Removal of fluoride from discharge gases decreases
markedly when the concentration of hydrofluorosilic acid in the recycle solution
exceeds 2 percent.”

Phosphate rock defluornation plants similar to that of the Rocky Mountain
Phosphates, Inc., plant in Garrison are operating in several other locations in
the United States. Most of these plants use water scrubbers as air pollution
control equipment.

Defluorinated phosphate rock is manufactured in Florida in one of the
largest and best equipped plants in the country. This plant had an air pollution
problem in the past, but installation of a three-stage water scrubber has eliminated
the problems. Effluent gases from the kilns are cooled by water sprays, scrubbed
in two packed spray scrubbers in series for removal of most of the fluoride, and
then passed through a milk-of-lime scrubber for removal of the remaining traces of
fluoride. Milk-of-lime solution is prepared in separate mixing equipment, and
only the overflow solution is added to the milk-of-lime scrubber. Overall effi-
ciency of fluoride removal for this plant is reported by the Florida Board of
Health to be greater than 99 percent.® This Florida plant has almost ten times
the pollution potential of the Rocky Mountain Phosphates, Inc., plant.


40

"HATES, INC.

Miles

AA, BB, CC : COLLECTED IN JANUARY 1965,
AH: COLLECTED APRIL 15, and 16, 1967.

Figure 16. Water sample collection locations in Garrison area.


2,500 Sf
T TT TTTTTTTTTTTTITTTTTTITTTT tf TTT I
GARRISON EAST STATION
2,000; ~— (1-1/3 miles from RMP) _
1,500}—
1,000 }— =
g 500}—
a ©
é
&
é 0 Li, itt to Litititi titi ii ti tit ity |
a JUNE O77" AMJJASONDIFMAMJJASONDJFMAMJJA
2 1,000
8 T T TTTTTTTTTTTTT TTT TTT tT Trt
3 GARRISON NORTH STATION
s (1-1/3 miles from RMP)
Ss
z= 500} —
otal lL, Ltt | bir Litt | Lit ITs |
JUNE 0 “RMIIAS ONDJFMAMJJASONDJFMAMJJA
1,000 f
, T TER CUTTTTTTTTTTTITTTTTT ttt TTT Tit 1
GARRISON WEST STATION
(5 miles from RMP) /
500}— / 4
/
/
/
| Loy gf titi terl | |i tit |
JUNE 0]  |AMJJASONDJJFMAMJJASONDUVFEFMAMJJA

36

1963 1965 1966 1967

Fluoride concentrations in grass specimens from Garrison area,
1965-1967.


RESOLUTION OF THE BOARD OF COMMISSIONERS OF POWELL COUNTY, STATE OF MONTANA,
REQUESTING THE SECRETARY OF HEALTH, EDUCATION AND WELFARE TO CALL A CONFERENCE
TO DEAL WITH THE PROBLEM OF AIR POLLUTION IN POWELL COUNTY.

WHEREAS, residents of the Garrison area of Powell County, Montana,
have petitioned the Board of Commissioners for Powell County, to request the
United States Secretary of Health, Education and Welfare to call a conference
to deal with the problem of air pollution in Powell County, Montana; and

WHEREAS, the Board of Commissfoners of Powell County is strongly
desirous of initiating an effective program leading to the prevention and
control of air pollution in this county,

NOW THEREFORE BE IT RESOLVED BY THE BOARD OF COMMISSIONERS OF
POWELL COUNTY, STATE OF MONTANA, that the United States Secretary of Health,
Education and Welfare is respectfully requested to call a conference, pursuant
to the provisions of Public Law 88-206 as amended by Public Law 89-272, to
deal with said pollution, On condition that Powell County bear no part of any
expenses or costs incurred.

Originally signed by:

Newman Raymond

Sandy 0. Reierson

R.M. Bauman

BOARD OF COMMISSIONERS FOR POWELL COUNTY

I concur in the above request.

TIM M, BABCOCK
Governor of the State of Montana

46


of one 2,400-pound batch about every 5 minutes. Approximate feed rates and
fluoride content of the feed material as supplied by Rocky Mountain Phosphates,
Inc., are as follows:

Phosphate rock 21,600 Ib/hr @ 3.4 - 3.6% fluoride
Soda ash 2,100 Ib/hr @ 0.1% fluoride
Phosphoric acid 3,960 Ib/hr @ 1.0 - 1.5% fluoride

Because the capacity of the mixing equipment is greater than the capacity
of the kilns, the mixing equipment is usually operated on 8-hour shifts at
required intervals to maintain sufficient “acid rock" feed material for the
kilns.

The acid rock from the mixer is dropped onto a conveyor belt and moved
to the storage building. Normal practice is to hold the acid rock in the
storage building 1 to 7 days prior to charging it to the kiln. This holding
time may vary, depending on product demand.

Acid rock is moved from storage to the calcination equipment by a
front bucket loader. The operator charges a load into the process at specified
intervals in an attempt to maintain a uniform feed. The feed material is
“run of pile" in particle size and must be crushed prior to entering the kilns.
Feed rate varies according to the time interval between charges and the weight
of acid rock in each load of the loader.

The acid rock is dropped onto a grizzly screen. Large lumps fall to the
floor, and lumps less than 3 inches in diameter fall to the charge hopper.
From the charge hopper the acid rock is moved by a bucket elevator to a crusher,
which reduces the particle size to 3/8 inch and drops the ground rock into a
surge tank. A vibrating feeder meters the material to a belt conveyor, which
feeds the kilns.

If feed to the belt were continuous , the kilns would be fed at a uniform
and continuous rate. Frequent equipment failures make it necessary to estimate
kiln feed rate from the frequency and weight of acid rock charges added to the
process. The feed is at the cold end of the kiln opposite the burners. Each
kiln is about 150 feet long and 8 feet in diameter. Natural gas is used as
fuel. The retention time of the material in the kiln is around 6 hours.
Temperatures in the kiln range from about 1800°F at the hot end to about 650°F
at the charging end.

As the defluorinated rock leaves the hot end of the kiln, it is cooled by
a water spray. The spray also supplies the moisture in the kiln essential to


winter nights are relatively long, surrounding mountains are a barrier to strong
winds, and snow cover during the colder months reflects away solar energy and is
an excellent radiator of heat at night. Furthermore, cool air in time drains to
lower elevations because of its greater density and thereby causes deeper and more
intense inversions in a valley than would occur on level ground.

A U.S. Weather Bureau study? reports the following inversion frequencies for
the general region of the United States in which Garrison is located:

Inversion frequency

Season Percent of
total hours
Winter 45-55
Spring 30
Summer 30-35
Fall 40-50
Annual 40

Protected mountain valleys such as the Deer Lodge Valley have even higher
percentages of inversions. In fact, the study indicates that the total of the
fall and winter frequencies of inversions for this and some of the other valleys
of western Montana is higher than for any other location in the contiguous United
States.

The behavior of a plume from a stack during stable, neutral, and unstable
conditions is shown in Figure 7. The unstable plume is described as "looping,"
the neutral plume as "coning," and the stable plume as "fanning." The cross sec-
tions of the looping and coning plumes are somewhat circular, whereas the fanning
plume is greatly flattened because of restricted vertical motion. Both the un-
stable and stable plumes, when viewed from above, generally show evidence of
meandering motion because of wind direction changes.

A plume from a source at the surface behaves similarly to that from a stack.
One difference, however. is that the maximum ground concentrations for pollutants
emitted from a stack occur some distance away from the stack, whereas with a ground
level source the maximum concentration is at the source and the concentration
decreases with increasing distance.

As would be expected, plume behavior is greatly affected by topography, and
it follows that ground concentrations of air pollution are also affected. Air is
channelled by a valley, especially during stable conditions; and a plume of air
pollution is confined by a valley, or will follow valley walls. Effluent from the

22


Table 6. FLUORIDE CONTENT OF WATER - APRIL 15-16, 1967,
PUBLIC HEALTH SERVICE ANALYSIS

Location Fluoride, ppm
A - Clark Fork River south of Deer Lodge 0.8
B - Rock Creek, Tavenner Ranch 0.5
C - Pond, Dutton Ranch 0.6
D - Carter Creek, 1 mi from Clark Fork 0.4
River
E - Brock Creek, 1 mi from Clark Fork River 0.8
F - Warm Springs Creek, Knope Ranch 1.0
G - Pond, Mollenberg Ranch 0.7
H - Little Blackfoot River, Lahman's 0.5

Trailer Court

FLUORIDES IN SOIL

Samples of soil were collected on May 23, 1967, and analyzed for fluoride
by the Montana State Board of Health. These samples, with locations of the
sampling stations the same as identified in Figure 14, yielded the following
results:

Sampling Station Map Location Fluoride, ppm
Garrison East 27 230
Garrison West 7 280
Garrison South 39 300

At the end of June 1967, topsoil and subsoil samples were taken from two of
these stations, and analyzed for fluoride content and for water-soluble fluoride
in laboratories of the Public Health Service. Results of these analyses are given
in Table 7.

I
Table 7. ANALYSIS OF SOIL SAMPLES FOR
WATER-SOLUBLE AND TOTAL FLUORIDE CONTENT

Fluoride, ppm

Sampling station Sample type Water soluble Total
Garrison East Topsoil 60 160
Garrison East Subsoil 60 160
Garrison West Topsoil 50 140
Garrison West Subsoil 60 180

41


POWELL COUNTY, MONTANA
AIR POLLUTION ABATEMENT ACTIVITY

I. Introduction

By letter of March 8, 1967, the Governor of the State of Montana forwarded
to the Secretary of Health, Education, and Welfare a resolution of the Board of
Commissioners of Powell County, Montana, requesting the Secretary to call a
Conference to deal with the problem of air pollution in the County. In forwardéng
the resolution, the Governor stated his concurrence in the request. Concurrence
was received from the Montana State Health Officer as wel}. The resolution of the
Powel] County Board of Commissioners, and a resolution of the Senate of Montana,
both recognize the air pollution problem in the Garrison area of the County.
Copies of the letters from the Governor and from the State Health Officer to the
Secretary of Health, Education, and Welfare, and copies of the Powell County and
the Senate resolutions appear in Appendix A.

Powell County, located in west central Montana, has an area of 2,337 square
miles and an estimated 1965 population of 7,300. The County seat is Deer Lodge.
The more than 200 farms and ranches in the County yield products valued at more
than $4,000,000 per year. Livestock production accounts for almost 80 percent of
the total value of the County's agricultural products. Powell County is shown
in Figure 1.

Garrison is located near the junction of the Clark Fork and the Little
Blackfoot Rivers, approximately 45 miles west of Helena, Montana. The town of
Garrison is situated in a mountain valley slightly west of the junction of U.S.
Highways 10 and 12. The valley floor is approximately 4,400 feet above sea level,
and the surrounding mountains rise to elevations of 9,400 feet.

Approximately 200 people live within a half-mile of the junction of
U.S. Highways 10 and 12. Garrison contains about 50 permanent homes, as shown
in Figure 2, and about 20 mobile units at Lahman’s Trailer Court about a half
mile south of the junction of the highways. -


ROCKY MOUNTAIN
PHOSPHATES, INC.

40

Willicme and
3 yavenner Ronch

! (Sampling sites are shown by
| small-sized numbers.)

N 50

Figure 14. Sampling sites and fluoride concentrations (ppm) for grass
specimens collected in Garrison area on April 15, 16, and
17, 1967.

This pattern is consistent with the growing season for grass and, in general, with
the seasonal fluctuations in production rate for the Rocky Mountain Phosphates, Inc.,
plant. During time of rapid grass growth the concentration of fluoride is lower
than during periods when growth is static, even though fluoride exposure continues.
Further reason for the observed pattern is the greater production rate for the

Rocky Mountain Phosphates, Inc., plant reported for the winter season than for the
summer. Seasonal fluctuations of fluoride content in grass from the three

locations are depicted in Figure 15.

34


IV. TOPOGRAPHY AND CLIMATOLOGY OF GARRISON AREA

TOPOGRAPHY

Garrison, Montana, is located at the fork of a Y-shaped mountain valley
system containing the Clark Fork River and the Little Blackfoot River. The town
is at the north end of the Deer Lodge Valley, which is approximately 35 miles
long and 8 to 10 miles wide, and which extends straight north and south, In the
vicinity of Garrison the Clark Fork River, which flows from the south, turns to
flow generally west-northwestward so that its valley forms the stem and left arm
of the Y. The Clark Fork River valley narrows and is curving in parts just west
of Garrison, but the valley straightens and widens further westward. At
Drummond, Montana, which is 20 miles west-northwest of Garrison, the valley
becomes 15 miles wide; but just west of there, it becomes very narrow and continues
so through high mountains for many miles.

The Little Blackfoot River begins near the Continental Divide, 25 miles east
of Garrison, and flows generally in an east-to-west direction. Its valley, which
forms the right arm of the Y, is relatively narrow where it cuts through the
Garnet Range, about 10 miles east of Garrison. In effect, Garrison, at 4,400 feet
mean sea level and surrounded by mountains 7,000 to 9,000 feet high, is ina
closed-off irregularly shaped, bowl-like valley system.

TEMPERATURE

Air temperature is important with respect to the air pollution problem in
Garrison, Montana, primarily because of its effect on the growing season. In the
Deer Lodge Valley, frosts and freezes do not have quite the same effects as in the
warmer parts of Montana, largely because growers concentrate on crops not suscep-
tible to damage at temperatures as low as 25° F. Crops grown in the area include
hay and grasses.

Based on 25 years of data, 1921-1950 (some data incomplete), the average
last date in spring for a temperature of 20° F is May 3, and the average first
date in fall for this temperature is September 30; consequently, there are 151
days in an average year between 24° F freezes.


WIND SPEED,mph

5

JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC

Figure 8.

CALMS , percent

MONTH

Average monthly wind speeds in Drummond, Montana - U. S. Weather
Bureau data from 1951 through 1954.

st td tt dt tt tt

JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
MONTH

Figure 9 Percent of calms each month during 1951 through
1954 in Drummond, Montana - U. S. Weather Bureau
data.

25


3

$3

§

2

x ANNUAL MEAN =

z 2.26 10.64 INCHES

ad *30 YEARS OF DATA
5 1.65

8 1.16

Soak 0.85 0.92 +
z 0.72 0.60 0.59

= 0.47 9,38 0-54 0.50
PLT | [||
20

g 0 oF mM A MJ 3g A S O N OD

« MONTH

=

5

=7 ANNUAL MEAN = = —
2 6}— 5 7 34 DAYS 4
ea s— 4 %*30 YEARS OF DATA 7
os 4 30 3

5 3L _—
oar) _ 2 2 2 2 J
oe | | | 5
g2° 9 F MAN 0 9 AS 0 NO
ge

MONTH
«
as
Ze aL 4.3 4.9 %22 YEARS. OF DATA 7
Ze ab a
2 3h 4
4 at 4
z7 GL ro 1S 7
ge a 0,1
=s JF M AM J J rn 1 ND
MONTH

Figure 6, Summary of precipitation records for Deer Lodge, Montana.

versions occur at night under clear or partly cloudy skies with calm or light winds.
When the ground cools by radiation, the layer of air above it also cools progres-
sively.

Mountain valleys, such as the one in which Garrison is located, are partic-
ularly subject to intense and long-lasting inversion conditions for several reasons.
The air in these valleys is usually an insignificant barrier to outgoing heat for
several reasons: it is less dense than air at lower altitudes and is generally dry,

21


Table 1. CONCENTRATION OF FLUORIDES IN GRASS SAMPLES
IN GARRISON, MONTANA, AREA®(ppm)

Garrison Garrison Garrison Garrison Garrison
Date of North East South West West
Collection Station Station Station Station Meadow Jens Deer Lodge

6/17/63 2 8

10/16/63 55 320
4/19/65 79 47
7/18/65 7 15
8/11/65 10 u 2
8/31/65 - WV 10
10/15/65 8 77 §3
11/17/65 20 148
12/17/65 92 132
1/12/66 170 220
2/9/66 564 416 767
3/15/66 860 1450 870
4/11-12/66 = 130 750 175
5/9/66 193 340 273
6/2/66 45 434
6/30/66 4 159 30
7/28/66 8 154 75
8/29/66 52 412 235 13
9/26/66 28 246 151
10/26/66 33 355 78 95 161 67 0
11/23/66 63 1000 231 26 316 4 0
12/21/66 m4 1750 484 362 590 83
1/20/67 380 - 695 380 4
2/16/67 327 - 450 230 340 200 70
2/24/67 - 2530
3/21/67 660 1750 97 598 106 198 25
4/25/67 «(127 1283 531 393 380 51 61
§/23/67 74 880 176 68 68 22 V7
6/23/67 28 182 10 28 9 2

asamptes collected and analyzed by Montana State Board of Health.


GAS OUTLET

ENTRAINMENT

SEPARATOR —x{ WR

LIQUOR 5

ie
pLastic___|§ sh

SPHERES
* GRID —~sf200.

; fit
cas fey
INLET thes

LIQUOR fe rere

OUTLET -
Figure §. Fluoride scrubber.

Equipment failures at the Garrison plant caused loss of cooling water in
the scrubber within a few months after it was installed in 1966. The gases
from the kiln at a temperature of about 650°F melted the corroston-resistant
lining and the plastic balls in the scrubber. Because of the low pH of the
circulating water, severe corrosion soon resulted and the. original scrubber was
destroyed within 6 months. In its place the Company ‘has erected two “plant
designed" scrubbers of somewhat similar design. :

One of. these.scrubbers is 6 feet . in diameter and the second is 8 feet
in diameter. The south scrubber still retains the top portion-of the commercial
scrubber ; however the bottom consists of several sections of concrete pipe.
Wooden supports and grids support the plastic balls, and restrain them from
passing out with the exhaust gases. The north scrubber has a steel..shell, but.
its internal parts also are wooden. To operate a scrubber of this. type
properly consideration must be given to both gas and liquid flow rates. Inan.
oversized scrubber, gas and liquid flow rates are too low for adequate turbulence
and efficiency of pollutant gas absorption is reduced. In an undersized. scrubber,
contact time is limited and inadequate absorption results.

‘As the result of the scrubber pump failures the wooden lining. and support.
structure if the existing scrubbers were charred by the hot.gases...Charred.pieces
of scrubber internal parts were found lying about the scrubber area. No alternative
method is provided at the present to insure water flow to the scrubber.

14


May 5, 1965
duly 1965 to
September 1965

July 1965 to
October 1965

February 1966

April 2, 1966

May 11, 1966

Summer 1966

September 1966

Late 1966

March 3, 1967
March 8, 1967

Suit brought by local ranchers to close Plant and to
collect damages.

Study of emissions at Plant made by Montana State
University for Judge W. W. Lessley.

Donald F. Adams, Court Consultant, studied ambient
air and vegetation in Garrison for Judge Jack Green.

First commercial scrubber installed at Rocky
Mountain Phosphates, Inc. James T. Tomany, engineer
for the vendor, testified that if the vendor's
scrubber was operated in accordance with design flow
rates, the fluoride removal from the stack gases
would be 98 percent and that a total of less than

7 pounds/hour would be emitted when the Plant was
producing 70 tons per day.

Final trial on ranchers damage action; $123,000
damages awarded. Decision now being appealed to the
Montana Supreme Court by Rocky Mountain Phosphates,
Inc.

Abatement action requested by ranchers denied by
Judge Lesstey. Decision being appealed to Montana
Supreme Court.

Plant stack collapsed and was replaced by discarded
product cooler, 4 feet diameter, 90 feet high.

Commercial scrubber severely corroded and removed
from service. Replaced by “plant designed" scrubber.

Second scrubber built by Rocky Mountain Phosphates for
use on No. 2 kiln.

Montana Air Pollution Control Law signed by Governor.
Governor Tim Babcock of Montana concurred in the

resolution of Powell County Board of Commissioners
requesting Federal Abatement Action in Powell County.


foot River Valley produces an east wind at Garrison. This air combines with
drainage from the Deer Lodge Valley to produce as east southeasterly wind down the
valley of the Clark Fork River from Garrison.

The Drummond wind rose shows 30 percent calm, whereas the Garrison rose
rose shows none. The apparent high frequency of calms at Drummond is caused by

the type of wind equipment in operation there. It is designed for routine aviation

purposes and is less responsive to both speed and direction than the wind system
in use at Garrison. A wind direction is not recorded unless a speed other than
zero is also observed. Also, the wind is observed only for 1 minute each hour,
when there may be no wind; whereas at Garrison the wind is recorded continuously
and any wind during the hour is considered in the hourly average values used for

constructing the wind rose. A large percent, if not all, of the calms for Drummond

represent low average hourly wind speeds of perhaps 1 or 2 miles per hour; and the
frequency of occurrence of various wind directions is actually greater than shown
‘in the wind roses.

An examination of the wind records at Garrison showed that the wind vane
was in a large eddy with slow wind speeds for intervals during many of the nights
when drainage flow was being established. At such times the wind vane would turn
slowly around, through 360 degrees or more, with the period of turning covering an
hour or two. Eighty such periods occurred during June. During some periods the
rotation was clockwise and during others it was counter-clockwise. At the end of
the period of vane rotation, wind direction was often southeasterly.

Wind direction is important in air pollution problems because it determines
the direction of transport of pollutants from the source. Wind direction frequen-
cies indicate the percent of the time a particular receptor is downwind. Calms,
light variable winds, or an eddy condition such as has been observed at Garrison
can result in relatively high concentrations distributed nearby and around the
source, and relatively great exposures or dosages near it.

31


ie} 5 10 15 20

l i | en er i J

PERCENT

Figure 11. Drummond, Montana, annual wind rose based on data from July 1950
through December 1954 - U. S. Weather Bureau record.

28


Figure 2. Map of Garrison, Montana.

were interrupted 35 times because of air pollution from the plant. During this
time court action was brought against Rocky Mountain Phosphates, Inc., by the
citizens of Garrison for alleged nuisance and health effects caused by the
emissions. Because of the serious complaints and court actions, technical
personnel from the Public Health Service, U.S. Department of Health, Education,
and Welfare; the Montana State Board of Health; and private consultants inspected
the plant and/or the vegetation in the area. All inspectors agreed that signifi-
cant quantities of fluoride and/or sulfur dioxide were released during the 1963
and 1964 growing season. Donald F. Adams, Technical Consultant to the Third
Judicial District Court, found varying degrees of needle burn of up to 100 percent.
on pinus ponderosa, depending on the distance and direction from the Rocky
Mountain Phosphates, Inc., operation.


ion

+

|

GARRISON MCDONALD
! PASS

i J
DEER LODGE a

Figure 1. Map of Powell County, Montana.

In 1963 Rocky Mountain Phosphates, Inc., installed a phosphate rock defluor-
ination plant in Garrison and began producing an animal feed supplement in August
of 1963. In the early days of its operation the plant had practically no air pol-
Jution control devices, and sulfur dioxide, acid mist, and gaseous and particulate
fluoride were released directly to the atmosphere. Vegetation damage and glass
etching were soon apparent. Montana State authorities received many complaints
about these emissfons.

Personnel from the Montana Board of Health analyzed grass samples from the
vicinity of the plant prior to operation and found fluoride concentrations of less
than 10 ppm. Very shortly after the plant began operating, the fluoride content
of the grass in the vicinity of the plant increased to over 300 ppm. Between
September 1963 and March 1964, classes at the Garrison Public School reportedly


In order for the scrubber to function properly, the fluoride content of
the scrubbing water must be controlled by adding lime to the scrubber water
either at the pump or at the pond. The desired result is that calcium fluoride
precipitates within the pond and thereby removes fluoride from the recirculating
water. Approximately 2 pounds of lime is required for each pound of fluorine
absorbed. When the plant was inspected in April 1967, no lime was being added
to the scrubber water. In fact, there was no lime available on the plant site.
At the time of this inspection both kilns were operating.

Good water distribution in the scrubbers is essential if high collection
efficiency is to be achieved. In a commercial scrubber, water sprays are
provided to insure good distribution and to prevent channeling. In the scrubber
designed by the plant the water is added in the top of the scrubber through an
8-inch pipe. This pipe ends within 12 inches of the scrubber wall and merely
dumps the water on the upper grid.

Scrubber water flows from the base of the tower to the pond and back
to the pump in open ditches. No method of preventing freeze-up during cold
weather operation is provided.

Both scrubbers are severely corroded. The most recently installed
scrubber was leaking from at least ten holes in the shell within 6 months
of installation.


February 1964

March 9, 1964

June 12 to 15, 1964

duly 27, 1964

August 1964

August 17. 1964
November 6, 1964

November 11, 1964
November 11, 1964
November 20, 1964

December 7, 1964

March 1965

April 5, 1965

April 1965

Hearing before Judge Haswell in Powell County with
plant's consulting engineer and R. Smith of Montana
School of Mines. Plant's consulting engineer stated
2,000 1b/day of fluoride being emitted.

Court action, Mollenberg et al. versus Rocky Mountain
Phosphates, Inc., before Judge Haswell in Powell
County.

Plant closed by court order; then allowed to open
again.

Plant ordered closed by State Board of Health as
health menace. Plant back in operation within a
few days.

80-foot section added to lengthen stack. Total
stack height increased to 210 feet.

Public Health Service. and State Board of Health
began stack testing at plant. Findings were
conclusive that controls were poor to nonexistent.

Plant ordered by State Board of Health to cease
operations until court order of June 10, 1964, had
been complied with. Plant closed for a few days.

Affidavit from Plant stating compliance with all
court orders. Production resumed.

Contempt order issued by State Board of Health.
Plant continued to operate.

Montana State Board of Health hearing with Rocky
Mountain Phosphates representatives.

Trial before Judge Jack Green at Deer Lodge, Montana.
Suit brought by State Board of Health on contempt
charge and charge that Plant was a menace to health.
A suit was also brought by Garrison citizens and
heard at the same time to abate the Plant as a
nuisance. Mrs. Ralph Davis, teacher at Garrison
School, was given authority to close plant during
2-week period. Board of Health authorized to close
plant if good reason could be given.

Plant defluorinating process changed from acid to
alkali process.

Ruling by Judge Green on December 1964 trial -
contempt charges disallowed; health hazard charge
disallowed; nuisance charge upheld. Plant shut down
for short time by order of Judge Green. Permitted
to operate again after few days to allow sampling by
Resources Research, Inc.

Plant capacity doubled by addition of second kiln.


LOOPING PLUME

UNSTABLE
ATMOSPHERE

1000

\
jes. uer-o|

1000 NEUTRAL
ATMOSPHERE

ELEVATION, feet

er]

STABLE
ATMOSPHERE

1000
FANNING PLUME

\
Jus. 4or—|
TEMPERATURE

Figure 7. Temperature lapse and plume behavior in unstable, neutral, and
stable atmospheric conditions.

Rocky Mountain Phosphates, Inc., stack moves up and down the Clark Fork River
Valley or up the valley of the Little Blackfoot River, following the turns in the
valley. It also spreads out over the ridges that project into the valleys. It
follows errosion channels up and down ridge slopes and tops the ridges at low
points. Consequently, exposed locations on slopes facing the source receive
relatively high concentrations,.as do draws on both sides of the slope where air

is channelled. Because of the “valley effect" high ground concentrations can occur
at a greater distance downwind from the source than would occur in flat terrain.

23


POWELL COUNTY, MONTANA
AIR POLLUTION ABATEMENT ACTIVITY

U.S. DEPARTMENT OF HEALTH, EDUCATION, AND WELFARE
Public Health Service
Bureau of Disease Prevention and Environmental Control
National Center for Air Pollution Control

duly 1967


APPENDIX B. ANALYTICAL METHODOLOGY FOR FLUORIDE

Various types of materials collected in the vicinity of Garrison, Montana,
were analyzed for fluoride content. The sample treatment for each type was
necessarily different; however, the measurement technique was the same for all
Samples except the water samples. Water samples were analyzed for fluoride with
an Orion fluoride selective electrode. All other samples were analyzed by the
Willard and Winter” distillation followed by the SPADNS”” colorimetric procedure.

Vegetation Specimens
Vegetation samples were analyzed for total fluoride on a dry basis. Some

samples were analyzed for water-insoluble particulate fluoride deposited on the
surface, and these or other samples were analyzed for water-soluble fluoride in
the deposited material.

Total Fluoride - Vegetation is blended with calcium oxide and a small amount of
water. The mixture is dried at 70° to 80° C, ignited at 600° C for 2 hours, and
fused with sodium hydroxide at 600° C for 10 minutes. This melt is dissolved in
water and neutralized with perchloric acid. The solution is then analyzed for
fluoride by the combined Willard and Winter distillation and SPADNS colorimetric
method.

Water-Soluble and -Insoluble Particulate Fluoride in Vegetation Samples - Total
fluoride content of vegetation samples can include fluorides incorporated into
the vegetation and particulate fluorides deposited upon the vegetation. To
estimate the amount not contained within the vegetation, selected vegetation
samples were washed gently with water. These washings were collected and
separated according to water-soluble and water-insoluble portions.

The insoluble portion was treated and analyzed in the same way as were
the vegetation samples. The soluble portion was distilled directly by the method
of Willard and Winter and measured by the SPADNS method.

Soil Samples
Soil samples were analyzed for both total fluorides and for water-soluble
fluorides.

*H.H. Willard and 0.B. Winter. Volumetric method for determination of fluoride.
Ind. Eng. Chem., Anal. Ed. 5:7-10. 1933.

**£. Bellack and P.J. Schoube. Rapid photometric determination of fluoride in
water. Anal. Chem. 30: 2032. 1958.

4g


TO GARRISON (1/4 MI )

RAW ROCK
RAW ROCK STORAGE
re ACID NORTHERN
STORAGE | PACIFIC
RR.
ROUTE 12
MIXING ]
HOUSE PHOSPHORIC | coacy
TRAILER COURT ACID
KILN
Re
(74 My) OK GAS
~— SCRUBBER
ACID ROCK
STORAGE
SHOP
KILNS
NOTE: Drawing not to scale.
BAGGING &
STORAGE
OFFICE | LAB
ae

y

TO DEER LODGE & BUTTE TO HELENA

ROUTE 10
Figure 3. Rocky Mountain Phosphates Inc. plant layout.


Il. ROCKY MOUNTAIN PHOSPHATES, INC..- PROCESS AND EMISSIONS ,

GENERAL

Rocky Mountain Phosphates, Inc., is engaged in defluorinating phosphate
rock to make a product suitable for an animal feed supplement. Phospate rock
used in this process ordinarily contains from 3.5 to 5 percent fluorine. In the
processing of phosphate rock for use as an animal feed, the fluorine content of
the defluorinated product must be reduced to at least 0.18 percent.

Two processes, the acid process, and the alkali process, have been used
by Rocky Mountain Phosphates, Inc., in removing fluorine from phosphate rock at
its Garrison plant.

Originally the acid process was used. This process involved adding
phosphoric acid and sulfuric acid to ground rock in a mixing operation. Sulfur
oxides, acid mists, and gaseous fluorides are released in this process. The
resulting mix, similar to normal superphosphate fertilizer, is passed through
a high-temperature, gas-fired kiln, where most of the remaining fluorides are
released. This type of process was used by the plant from the beginning of its
operation until early in 1965 when the process was changed to the alkali process.
The protess now used is essentially a modification of the soda-ash process
patented by the Smith-Douglas Company of Norfolk, Virginia, under U. S. Patents
2,839,377, dated June 17, 1958; and 2,995,437, dated August 8, 1961.

Only the mixing operation is changed in converting from the acid to the
alkali process. Ground phosphate rock, phosphoric acid, and soda ash are mixed
to form a relatively dry mixture called “acid rock." Little or no emissions
are released in the mixing operation. The resulting “acid rock" is further
processed in the fired kiln to release the fluorides in a manner similar to that
of the acid process.

PROCESS DESCRIPTION

Figure 3 shows the plant layout, and Figure 4 is a flow diagram of the
defluorination process. The mixing operation is performed in a small pug mill.
The phosphate rock, soda ash, and phosphoric acid are transferred from storage
to small weigh tanks directly above the mixer. These feed materials are charged
to the mixer in the proper proportion. Mixing is continued at a steady rate


State of Montana
Office of The Governor
Helena

March 8, 1967

Mr. John Gardner
Secretary of Health, Education, and Welfare
Washington, D.C.

Dear Secretary Gardner:

I am forwarding herewith a resolution of the Board
of County Commissioners of Powell County, Montana, together with
my concurrence to initiate an abatement proceeding by the National
Center for Air Pollution Control under Section 105 of the Clean Air
ict.

This matter has been discussed with representatives
of the abatement. control division of the center, and I was at one
point advised that they might conceivably be far enough along with
several interstate abatement proceedings then pending to give
attention to our problem sometime this month.

Sincerely yours,

Tim Babcock
GOVERNOR

cc: Mr. S. Smith Griswold
Dept. of Health, Education, and Welfare
Washington, D.C.

Mr. Newman Raymond, Chairman
Powell County Commissioners
Deer Lodge, Montana

Ab


30

GARRISON, MONTANA

%
CALM yey 1318225 5 10 15 20
Op] ° Litt tif
0-3 8-12 79-24 PERCENT
SPEED, mph

DRUMMOND, MONTANA.

Figure 13. June 1967 wind roses for Garrison and Drummond, Montana.


Total Fluoride - The sample was dried at 75° ¢ and passed through a 100-mesh sieve
to remove small stones and vegetation. The dry sample was blended with calcium
oxide, ignited at 600° C for 2 hours, and fused with sodium hydroxide at 600° C for
10 minutes. The melt was dissolved in water and neutralized with perchloric acid.
This solution was analyzed by the SPADNS method after perchloric acid distillation.

Water-Soluble Fluoride - The dried sample of soil was blended with water and
filtered. The filtrate was analyzed by the SPADNS method after distillation from
perchloric acid.

Water Samples
The fluoride content of water was measured instrumentally by means of an
Orion fluoride selective electrode.

50


JANUARY t APRIL
N

PERCENT

Value in center is percent calm.

JULY OCTOBER

Figure 12. Wind roses for January, April, July, and October from 1950 through
1954 for Drummond, Montana - U. S. Weather Bureau data.

29


During the time of these early complaints and court trials, the company
installed spray towers in an attempt to remove the fluorides from the exhaust
gases. In August of 1964 personnel from the Public Health Service and the
Montana State Board of Health conducted a stack test at the plant. The findings
of this stack test indicated conclusively that the collection equipment provided
by Rocky Mountain Phosphates, Inc., was ineffective in removing fluorides from the
stack gases.

Reports of these studies also testify to the poor maintenance and operating
procedures applied by the Company to limit pollution.

Further court action filed by local ranchers in 1965 alleged cattle damage
by fluorides emitted by the plant. The court ruled in favor of the plaintiffs in
this case and awarded $123,000 in damages.

Complaints against the plant continued, and in a letter dated March 8, 1967
Governor Tim Babcock of Montana concurred in a request by the Powell County Board
of Commissioners for the Secretary of Health, Education, and Welfare to initiate
a Federal air pollution abatement action under the provisions of Section 105 of
the Clean Air Act (42 U.S.C. 1857 et seq.).

The following is a brief chronological record of the plant operation:
(Approximate Dates)

January 14, 1960 Plant opened in Butte, Montana. Complaints were
received by Montana Board of Health almost immedi-
ately. One school was interrupted several times,
and a nuisance action was filed but no action was
taken.

August 1, 1963 Plant began operation in Garrison. Complaints of
severe air pollution were made to Montana Board of
Health soon after plant began operating.

September 1963 to Garrison school interrupted 35 times by gas and
March 19, 1964 smoke.
October 1963 Donald F. Walters, Engineer, Public Health Service

inspected the plant with Benjamin F. Wake of the
Montana State Board of Health.

October 1963 Court action brought by citizens of Garrison against
Rocky Mountain Phosphates, Inc.


PRECIPITATION

Official precipitation records are not available for Garrison, Montana,
but 30 years of data are available for Deer Lodge, about 10 miles to the south
Other locations in the general area for which precipitation data are available are
Drummond, 19 miles west-northwest and Elliston, 18 miles east. The mean annual
precipitation for Deer Lodge is 11 inches; Drummond, 11 inches; and Elliston, 16
inches. The mean annual precipitation for Garrison, Montana, is estimated to be
about 12 inches.

Figure 6 shows monthly means, mean number of days with precipitation of 0.10
inch or more, and monthly means of inches of snow and sleet on the ground for Deer
Lodge. The pattern of distribution of precipitation throughout the year is similar
to those for Drummond, Elliston, and the Garrison area. In Deer Lodge, 7.56 inches,
or 71 percent, of the precipitation falls during the growing season (April-September )
Normal years, therefore, have enough rainfall for many types of dryland farming
and ranching. The winter is relatively dry, with February, the month with the
least precipitation having only one-sixth that of June, the wettest month. Snow-
fall in the surrounding mountains provides enough water for irrigation during most
of the summer in many years.

ATMOSPHERIC STABILITY

If in the atmosphere the temperature decrease with elevation is greater than
5.4° F per 1,000 feet, conditions are described as “unstable” and air pollution is
readily dispersed. Such a condition generally occurs on sunny days when the ground
becomes heated and warms the air above. Wind speeds are low and wind directions,
variable on such days.

If the temperature decrease is close to 5.4° F per 1,000 feet, the atmospheric
stability is “neutral.” When atmospheric conditions are neutral, dispersion poten-
tial is relatively good. The meteorological conditions associated with neutra
stability are cloudy skies and strong enough winds to cause thorough mixing. Wind
directions are more or less steady.

If the temperature decrease with elevation is less than 5.4° F per 1,000
feet, conditions are “stable.” As the rate decreases, the dispersion rate for air
pollutants also decreases. If the temperature of the atmosphere increases with
elevation, dispersion of air pollutants is poor

The condition in which temperature increases with elevation is called a
"temperature inversion." The base of a layer of temperature inversion may be
located either at the surface or aloft. Over land, surface-based temperature in-

20


Table 2.

FLUORIDE CONCENTRATIONS IN GRASS SPECIMENS

COLLECTED APRIL 15-17, 1967, BY PUBLIC HEALTH SERVICE

Station Location Fluoride, ppm
1 1/2 mi north of RMP 8,400
2 }-1/2 mi north of RMP 200
4 2 mi NW of RMP 1,600
6 4 mi WNW of RMP 250
7 4-1/2 mi NW of RMP 800
9 5 mi west of RMP 50
10 6 mi WNW of RMP 700
vv 8 mi NE of RMP 60
12 8 mi NW of RMP 80
13 8 mi NW of RMP 70
14 7 mi NW of RMP 80
15 9 mi NW of RMP $5
18 5 mi ESE of RMP 70
19 7 mi SE of RMP 260
20 9 mi SE of RMP 70
21 4 mt SE of RMP 290
22 3 mi south of RMP 80
23 5 mi SSE of RMP 180
24 15 mi SSE of RMP 165
25 13 mi SSE of RMP 300
26 8 mi SE of RMP 300
27 1-1/2 mi east of RMP 1,500
29 3 mi ESE of RMP 240
34 2-1/2 mi ESE of RMP 430
35 7 mi ENE of RMP 240
36 11 mi ENE of RMP 40
37 12 mi NE of RMP 25
38 11 mi WNW of RMP 60
39 2 mi SSE of RMP 970
40 3 mi SSW of RMP 95
4) 7 mi SW of RMP 50
43 1-1/4 mi south of RMP 710
49 1500 ft SE of RMP 11,000
50 1 mi NW of RMP 2,400
51 1/2 mi ESE of RMP 12,600

Rocky Mountain Phosphates, Inc.

38


Table 3. FLUORIDE CONTENT OF WASHED GRASS
SPECIMENS AND OF WATER WASHINGS

Parts Per Million Fluoride

Station Unwashed Grass Washed Grass Washings®
49 11,000 9,400 940
51 13,000 10,000 820

@As ppm of grass sample.

Table 4,

FLUORIDE CONTENT OF EVERGREEN FOLIAGE
COLLECTED IN APRIL 19672

Type of evergreen

Location

Fluoride, ppm

Fir lm
Juniper 5 mi
Ponderosa Pine 8 mi
Ponderosa Pine 8 mi
Ponderosa Pine 25 mi
Ponderosa Pine 25 mi
Ponderosa Pine 12 mi

east of Garrison

WNW of Garrison (Clark Fork Valley)
WNW of Garrison (Clark Fork Valley)
WNW of Garrison (Clark Fork Valley)

east of Garrison (West Side of
MacDonald Pass)

NNW of Garrison (Helmville)
WNH of Garrison (Jens)

760
80
50
60
40

10
30

@Specimens collected and analyzed by Public Health Service personnel.

Table 5. FLUORIDE CONTENT OF WATER SAMPLES COLLECTED ON
JANUARY 8, 1965, MONTANA STATE BOARD OF HEALTH

Location Fluoride, ppm

AA - Lahman's House 0.2
12-foot dug well

BB - Warm Springs Creek 1.4
William Knope Ranch

CC - Welsh's Truck Stop 0.2

Samples of surface waters in the Garrison area were collected on Apri] 15
and 16, 1967, and analyzed for fluoride content in Public Health Service
laboratories. Locations from which these samples were obtained and results of
Table 6. Locations are shown in Figure 16.

the analyses are shown in

39


from its sheltered location. The average speed for the month of June 1967 was
only 3.8 miles per hour.

For comparison, the average June wind speed for Washington, D. C.,is 9
miles per hour; Los Angeles, California, 8 miles per hour; and St. Louis, Missouri,
8 miles per hour.

In Garrison during June, the highest hourly average speed of 7 mph occurred
at 3 p.m., whereas the wind speeds during the hours 10 p.m. to 6 a.m. average 2
miles per hour or less (Figure 10). Examination of the wind record showed that
true periods of calm when no air movement was detected are rare in Garrison. Wind
speeds of at least 1 or 2 mph occur most of the time. During the hours of darkness,
when calms are most likely to occur, cold drainage off the slopes causes some move-
ment of air.

8.0,

PrTTTTT TTT PT rr rrr rrr ro ri

Average speed for
period 3.8 mph

WIND SPEED,mph

MID 02 O08 06, 08 10 12 14 16 18 20 22 MID
HOURS OF DAY

Figure 10. Average hourly wind speed for June 1967 in Garrison, Montana.

Wind speed is very significant in air pollution considerations. With
respect to a continuous point source, such as emissions from a stack, ground level
concentrations are inversely proportional to wind speed, i.e., low wind speeds
produce high concentrations. Also, in the Garrison valley area, where air pol-
lution can be confined by surrounding hill and mountain sides, low wind speeds are
associated with atmospheric processes that permit air pollution to accumulate in
the vicinity of a continuous source and remain in the general vicinity of it for

many hours.

26


Introduction ....... be eeeeneee ererrererr retry seen e eee e eee eeeeeeee sooner T
II. Rocky Mountain Phosphates, Inc. - Process and Emissions ...........+04- 7

General 7

Process Description ...... 77

Air Pollution Emissions .. Vu

Design, Operation, and Maintenance Deficiencies ........ssceceeseccenee 12
III, Fluoride Emission Control Technology ........2sseceececeseeeceeccereees iv
IV. Topography and Climatology of Garrison Area ......cceeseececcecseeeeees 19

Topography .. :

Temperature .

Precipitation .

Atmospheric Stability 20

Wind Speed ..

Wind Direction ........... seeeeeee 27
V. Distribution of Fluoride in Garrison Area ........ Sent eceereeeeees sooo 33

Fluorides in Grass ..... Sateen teen eeeee 33

Fluorides in Evergreen Foliage 37

Fluorides in Water .......eee06 37

Fluorides in Sof) ......ecceceseseeeeeeeee seeseecnccsescescceesccssces AT
APPENDICES ........ errr errr Perrer er reer errs eeeeeee nes sees 43

REFERENCES ........

Appendix A Correspondence and Resolutions
Appendix B Analytical Methodology for Fluoride ..

43



SENATE
JOINT RESOLUTION NO. 1

INTRODUCED BY FLYNN, McKEON

A RESOLUTION OF THE SENATE OF MONTANA URGING THE GOVERNOR TO REQUEST
THE SECRETARY OF HEALTH, EDUCATION, AND WELFARE TO CALL A CONFERENCE
ON AIR POLLUTION IN THE VICINITY OF GARRISON, MONTANA.

1 WHEREAS, the people, the animals, and the plant life in the

2 vicinity of Garrison have suffered, are suffering, and will con-

3 tinue to suffer from the demonstrated effects of air pollution

4 which endangers their health and welfare; and

5 WHEREAS, the federal Clean Air Act makes provision for the

6 Secretary of Health, Education, and Welfare to call a conference

7 if such air pollution exists whenever requested by the Governor of
8 any State.

9 NOW, THEREFORE, BE IT RESOLVED BY THE SENATE OF THE STATE OF

10 MONTANA:

nv That the Governor is urged to request the Secretary of Health,
12 Education, and Welfare to call a conference, as provided in the
13 Clean Air Act.

14 BE IT FURTHER RESOLVED, that the Secretary be requested to

15 direct such conference to consider, among such other matters as

16 the Secretary may deem appropriate, the occurrence of air pollution
17 in the vicinity of Garrison, the adequacy of measures taken

18 toward abatement of the pollution, and the nature of the

19 delays, if any, being encountered in abating the pollution.

47


State of Montana
State Board of Health
Helena, Montana

AIR MAIL

March 21, 1967

Mr. John Gardner, Secretary
Health, Education, and Welfare
Washington, D.C.

Dear Secretary Gardner:

I concur with the resolution of the Board of County
Commissioners of Powell County, Montana, forwarded to you by
Governor Tim Babcock on March 8, 1967, in his request to you for
initiating abatement proceedings at Garrison, Montana, under the
federal Clean Air Act.

This department will cooperate with you to the fullest
extent possible. It is my hope that action can be initiated with
a minimum of delay.

Sincerely yours,

John S. Anderson, M.D.
Executive Officer

JSA/acw

cc: Mr. Griswold, National Center for Air Pollution Control
Governor Tim Babcock, Capitol Building, Helena, Montana
Mr. Newman Raymond, Chairman, Powell County Commissioners
Deer Lodge, Montana

45


fluoride removal. The cooled product is screened to separate large pieces,
crushed as required to meet specifications, and discharged into a hopper for
storage. The product may be bagged for sale or may be sold in bulk. The
product is about 16 mesh in size and contains less than 0.18 percent fluorine.
The product trade name is "Feed Phos."

The exhaust gases leave the charge end of the kiln and pass through
a water scrubber and a blower, and into a common stack. Separate water
scrubbers and blowers are provided for each of the two kilns. The exhaust
gas rate for each kiln is between 14,000 and 17,000 scfm. The gases, leaving
the kiln at about 650°F, contain‘water vapor, gaseous fluorides, particulate,
and combustion products.

The water for the two scrubbers is supplied from a pond located about
200 yards south of the scrubbers. The water flows from the pond to the base of
the scrubbers and returns to the pond in open ditches. Adjacent to the

scrubbers, a sump pump forces water in an 8-inch line to an overhead water tank.

This tank is kept full at all times, and the overflow from the tank is divided
‘into the two scrubbers. Water rate to the scrubbers is reported to be from
1,000 to 1,500 gallons per minute. The pond is about 80 feet wide, 150 feet
long, and 4 feet deep.

AIR POLLUTANT EMISSIONS

Air pollutant emissions from the Rocky Mountain Phosphates, Inc., rock
defluorination plant are of two types, particulates and gaseous. Particulate
emissions from the crushing, bagging, and handling of both the feed and product
result in a fine gray dust, which covers buildings, cars, yards, and other
exposed surfaces in the vicinity. These emissions for the most part, consist
of relatively large particles, which normally settle near the plant property.
Particulate released from handling the feed material contains 3.5 to 5 percent
fluorine; particulate from product handling contains no more than the 0.18
percent fluorine permissible in the finished product.

Gaseous pollutants escape from the plant processing equipment and the
stack. The reactions involved in the defluorination of phosphate rock and the

chemical analysis of the rock itself are quite complex. Typical of the reactions

thought to occur in defluorination is the following:
(CaF) Cay (P04)3 +7 HPO, +5 H,0 —> 5 CaHy (PO4)2"H,0 + HF,


scrubbing solution continually increases. Unless lime is added to remove the
fluoride from the scrubbing water, the efficiency of the scrubber is reduced.
Rocky Mountain Phosphates, Inc., frequently has operated the plant without
addition of lime. During a plant inspection on April 12, 1967 no lime was
available for addition to the scrubber, but both kilns were being operated.

3. Poor fabrication of piping, which results in direct discharge of
pollutants to the atmosphere. A specific example is the copious leakage of
fluoride gases at the charge end of the kiln. Some attempt was being made in
the Spring of 1967 to correct this situation, but the plant has continued to
operate many months with this condition existing. Another example is the poor
construction of the gas inlet of the south scrubber. An opening about 4 by
12 inches in this line, adjacent to the scrubber, was noted during the inspection
of the plant on April 12, 1967.

4, Poor water distribution in the scrubbers. During the plant
inspections of August 1964, one-third of the spray nozzles were completely
plugged. The reduced scrubbing capacity results in decreased fluoride collection
efficiency. In the inspection of April 1967 no method of water distribution
was provided in the scrubbers.

5. Corrosion of piping which results in leakage of gas and scrubbing
water, indicates generally poor maintenance. Toxic gas is discharged through
these holes at ground level, where there is little chance for atmospheric
dispersion. In addition, holes in gas piping reduce the draft on the equipment
and affect the collection of toxic gases from the kiln.

6. Lack of spare or standby equipment to insure continuous operation of
air pollution control equipment. The south scrubber, purchased from a commercial
company, originally consisted of several beds of plastic spheres supported on a
grid similar to that depicted in Figure 5. Spray nozzles distributed the
scrubbing liquid uniformly over the packed section. Several beds of spheres
were provided. The gas to be cleaned entered the scrubber near the bottom and
traveled upward through the sphere bed while the scrubbing liquid cascaded down
from the spray heads at the top. Under the influence of this counter-current
gas and liquid flow, the spheres are forced into violent, random motion, and
impinge against each other.

The unit functions in this manner to provide contact surfaces for
absorbing gases and also serves as a gas cooler. Several types of scrubbers
of this general design are available commercially. .


Following the Powell County, Montana, Air Pollution Abatement Conference a
comprehensive report including this report; the Conference presentations of the
Department of Health, Education, and Welfare; and the recommendations resulting
from the Conference, will be prepared and made available for general distribution.


The concentrations of fluoride found in grass specimens from the Deer Lodge
and Jens stations (map locations 16 and 42) are generally lower than those from :
the other stations. The Jens and Deer Lodge stations are located farther from
the Rocky Mountain Phosphates, Inc., plant than are the other stations.

Some 50 grass specimens were collected in the Garrison area April 15 to 17,
1967, by personnel of the Public Health Service and the Montana State Board of
Health. Thirty-five of the Powell County specimens, selected to give good
geographic distribution, were analyzed for fluoride content in Public Health
Service laboratories. Analytic methods and sample handling procedures used in the
Public Health Service laboratories for the vegetation specimens, and other samples
examined for fluoride, are referenced or described in Appendix B.

Locations and fluoride concentrations for the April specimens are listed
in Table 2. Results of the analyses and the topographic features of the area
were used to estimate the locations of isopleths of fluoride concentration in
grass for mid-April 1967 in the Garrison area. The locations from which grass
specimens were collected and the estimated isopleths of fluoride concentrations
are shown in Figure 14.

Grass specimens from two of the locations listed in Table 2 were washed
gently with water, and the washed grass and washings were then analyzed for
fluoride. The technique, while not precise, yields information on the relative
amounts of fluoride materials readily removed from the surfaces of the specimens.
Results of these examinations are shown in Table 3. Some 5 to 10 percent of the
fluoride was removed by gentle washing of these specimens.

FLUORIDES IN EVERGREEN FOLIAGE,

Specimens of evergreen foliage were collected in the Garrison area
April 15-17, 1967 and analyzed for fluoride content in laboratories of the
Public Health Service. Two-inch long portions from the tips of the needles were
analyzed. “The type of tree, its location, and the concentration of fluoride in its
foliage are listed in Table 4.

FLUORIDES IN WATER

Water samples were collected in three locations in the Garrison area in
January 1965 and analyzed for fluoride content by the Montana State Board of
Health. Locations from which these samples were obtained and results of the
analyses are shown in Table 5. Locations,identified by letter, are shown in
Figure 16.

37


WIND SPEED

The Montana State Board of Health operated a wind recording system on the
roof of the County Courthouse in Deer Lodge from November 1965 through June 1966.
Calm or very light winds, with wind speeds ranging from 0 to 7 miles per hour,
were observed 70 percent or more of the time in all months except December (65
percent) and June (58 percent). In February, the month with most light winds,
speeds of 0 to 7 miles per hour were observed 91 percent of the time, !0

A Public Health Service wind recording system installed on the north edge
of Lahman's trailer court began to record data in mid-May of 1967. The light-
weight design of the wind vane and anemometer cups makes it possible to record wind
conditions when speeds are as low as 1 mile per hour. The wind sensors are located
on top of a telephone pole, approximately 20 feet above the ground.

Without a longer period of observational records from Garrison, monthly
wind conditions throughout the year and annual average conditions must be estimated
from observations made at the Drummond airport, 20 miles west-northwest down the
Clark Fork River Valley. At the present time wind observations are made at Drummond
only during the hours of 0500 to 1700, but summarized data are available for 24
hours daily for the years 1951-1954. Although the topography at Garrison and the
Drummond airport are different, a comparison of the limited amount of Garrison data
with Drummond observations shows that wind conditions are similar. The average
wind speed at Drummond for the month of June 1967 during the hours of the day the
station operates was 4.4 miles per hour. The average wind speed for the same hours
at Garrison was 4.6 miles per hour, an insignificant difference.

As is shown by the graph of average monthly wind speeds for Drummond, Figure
8, there is a seasonal variation of wind speed in the Garrison area. At Drummond
October, November, and December have the lowest wind speeds. The average monthly
speed for these months is about 6 miles per hour. Highest monthly averages occur
from January through July, when wind speeds average about 8 miles per hour.

The greatest number of periods of calm occur in Drummond during the late
fall and early winter. A calm is reported in about 12 percent of all observations
during the months of November and December, Fewest calms occur during the warmer
months of the year, April through September, when calms occur only 5 to 6 percent
of the time (Figure 9). Annually, wind speeds in the range of 0 to 7 miles per hour
occurred 52 percent of the time.

The limited amount of wind speed data available for Garrison, Montana,
indicates that average wind speeds are relatively very low, as would be expected

24


POWELL COUNTY, MONTANA
AIR POLLUTION ABATEMENT ACTIVITY

PRE-CONFERENCE, INVESTIGATIONS

Prepared for Conference Use Only

U.S. DEPARTMENT OF HEALTH, EDUCATION, AND WELFARE
Public Health Service
Bureau of Disease Prevention and Environmental Control
National Center for Air Pollution Control

July 1967


REFERENCES

Adams, D.F., An air quality survey, Garrison, Montana, July 5 - November 13,
1965. January 1966.

Goodwin, D.R., Report on air pollution emissions from Rocky Mountain Phosphates,
Inc., Garrison, Montana, August 18-22, 1964. Taft Sanitary Engineering Center,
Cincinnati, Ohio. October 1964.

Lenfesty, F.A., T.D. Farr, and T.C. Brosheer. Industrial and Engineering
Chemistry, 44: 1448-50. 1952.

Semrau, K.T., Emission of fluorides from industrial processes - a review
JAPCA. 7:92-108. August 1957.

Scuter, R.C. and M.A. Hannah. Industrial Development Center Report on Rocky
Mountain Phosphates Plant operation in connection with the cases of David
Dulton et al. and Edward and Isabelle Mollenberg vs. Rocky Mountain Phosphates.
July 12, 1965.

Douglas, H.R., W.A. Snider, and G.H. Tomlinson, An evaluation of mass and heat
transfer in the turbulent contact absorber. Presented at 50th annual meeting
of American Institute of Chemical Engineers. Buffalo, New York. May 8, 1963.

Specht, R.C, and R.R. Calaceto. Gaseous fluoride emissions from stationary
sources. Chemical Engineering Progress. 63:78-84. May 1967.

Huffstutler, K.K. and W.E. Starnes, Source and quantities of fluorides

evolved from manufacture of fertilizer and related products. Presented at Air
Pollution Control Association Annual Meeting. June 20-24, 1966. San Francisco,
California.

Hosler, C.R. Low-level inversion frequency in the contiquous United States.
Monthly Weather Review 89:319-39. September 1961.

A study of air pollution in the Deer Lodge Valley, August 1965.- June 1966.

Montana State Department of Health, Division of Disease Control. Helena,
Montana. 29 pp.

51


V. DISTRIBUTION OF FLUORIDE IN GARRISON AREA

FLUORIDES IN GRASS

Vegetation absorbs hydrogen fluoride when the gas is present in the ambient
atmosphere. The accumulation of fluoride in vegetation can be determined by
chemical analysis.

Specimens of grass from several locations in the Garrison area were
collected during 1963, 1965, 1966, and 1967 and analyzed for fluoride content by
the Montana State Board of Health. Locations from which these specimens were
taken are identified as follows on the area map, Figure 14:

Station Map location
Garrison North 2
Garrison East 27
Garrison South 39
Garrison West 7
Garrison West Meadow 50
dens 16
Deer Lodge 42

The concentrations of fluoride in the specimens taken from these locations and
the dates upon which the specimens were collected are listed in Table 1. The
earliest specimens from the Garrison North and Garrison East stations were taken
on June 17, 1963, before operation of the Rocky Mountain Phosphates, Inc., plant
began. The results are consistent with fluoride content of such specimens from
locations where there is no substantial source of atmospheric fluoride.

Data for an interval of about 2 years following the beginning of operation
of the Rocky Mountain Phosphates, Inc., plant in Garrison are available for the
Garrison North, Garrison East, and Garrison West stations (map locations 2, 27,
and 7). The month-by-month concentrations of fluoride in grass specimens from
these locations exhibit a consistent pattern. Concentrations increase rapidly
during the late autumn to very high values during the late winter, decrease during
the spring, and remaim relatively lower than winter values during the summer.

33


APPENDIX A.

APPENDICES

CORRESPONDENCE AND RESOLUTIONS

Letter from Governor T. Babcock to Secretary J. Gardner
Letter from Dr. J. S. Anderson to Secretary J. Gardner
Resolution of Powell County Board of Commissioners

Resolution of Senate of Montana

43


WIND DIRECTION

Topography greatly influences wind direction in the Garrison area. It also
is a factor at Deer Lodge, where wind records were obtained by the Montana State
Board of Health in May 1966, and at Drummond, the nearest station making official
wind observations. The limited data for Deer Lodge confirmed the north-south
channelling of air by the north-south orientation of the Clark Fork River Valley
in the vicinity of this city. Few westerly and hardly any easterly winds were
observed. The sheltering effect of the mountains is shown by the fact that 21
percent of the winds were classified as light and variable.

Wind direction data for the Drummond, Montana, airport are available for
all hours of the day for the period.July 1950 through December 1954; these data
have been summarized by the U.S. Weather Bureau. At the present time, however,
meteorological observations, including hourly wind direction readings of an instru-
ment by a Federal Aviation Administration observer, are made daily only for the
hours 0500 through 1700.

The annual wind rose for Drummond (Figure 11) gives the percent frequency
of occurrence of wind directions and speeds for each direction and the percentage
of calm. The relative high frequency of winds from the west through northwest.
shows the effect of the prevailing westerlies of this latitude. Cold air also
drains off the nearby hill sides from a westerly direction. The higher frequency
of southwest and northeast winds are indicative of the effect of the Flint Creek
Valley and a pass through the Garnet Range in a general northeasterly direction
from Drummond. Because of the manner in which large-scale meteorological features
affect this region, a large percentage of easterly winds would not be expected.
Further, airflow from east to west is inhibited by the high mountains west of
Drummond and the narrow, winding nature of the Clark Fork River Valley to the west.

Figure 12 shows wind roses for the 4 months of the year representative of
the four seasons. There do not appear to be important seasonal differences in
direction, as is often the case at weather stations in other geographical regions.

Because wind data for June 1967 are available for Garrison, the wind roses
shown in Figure 13 were prepared for both Drummond and Garrison. Only the hours
between 0500 and 1700, inclusive, were used. These correspond to the part of the
day when the Drummond Station is operating. Both of these wind roses show wind
frequencies of 20 percent from a northwesterly direction, a pattern similar to that
seen in the annual wind rose for Drummond. The Garrison wind rose shows a much
greater frequency of winds from the east (13%) than Drummond (1%). Air draining
from the mountain slopes west of the Continental Divide and down the Little Black-

27


PHOSPHATE
ROCK
STORAGE

STORAGE OF ACID ROCK

PUG MIXER

-——

CRUSHER
GASEOUS SURGE TANK PARTICULATE
FLUORTDES q
FEEDER
7 C4 GRINDER
SCRUBBER |oug—| ROTARY KILN SCREEN
CYCLONE
BLOWER COOLING NATURAL | COARSE
WATER GAS STORAGE
L
FUE BIN PRODUCT
TO BAGGING
POND AND BULK
LOADING

Figure 4,

Flow diagram of Rocky Mountain Phosphates; Inc., phosphate rock
defluorination plant in Garrison, Montana.


Silicon tetrafluoride may also be formed at elevated temperature by a
number of reactions. It is probable that both hydrogen fluoride and silicon
tetrafluoride are formed.

The gaseous phase reaction of water vapor with silicon tetrafluoride
under high-temperature conditions has been studied by Lenfesty et al3,
who found that the equilibrium favored the formation of hydrogen fluoride at
high temperature. The following reaction is involved:

SiF, (g) + 2 H,0 (g) =— Sid, (s) + 4 HF (9)

Semrau* reports that no significant amounts of silicon tetrafluoride
should exist as such in moist, high-temperature furnace gases, the conditions
which exist at the Rocky Mountain Phosphates, Inc., plant.

Plant inspections have revealed that fluoride emissions come from three
locations and appear to be about equally divided among these locations. The
normal point of discharge is the top of the stack, where the fluoride content
of the effluent depends upon the efficiency of the scrubbing equipment. A
second emission comes from the many leaks in and around the bottom of the stack
and in the piping. These emissions are practically at ground level. Fluoride
content here also depends upon the efficiency of the scrubbing system. A third
emission source, perhaps the most significant, is leakage at the end of the
kiln where the gases are collected for transport to the scrubbing system. This
emission, which can be detected visually during nighttime observations, contains
completely unscrubbed gases having high concentrations of fluoride. This
emission is also practically at ground level.

DESIGN, OPERATION, AND MAINTENANCE DEFICIENCIES

Deficiencies in design and in operation and maintenance practices at
the Rocky Mountain Phosphates, Inc., plant have contributed greatly to the
emission of fluerides. This condition began when the plant originally started
operating without air pollution control equipment and has generally continued to
the present time. Evidence of these poor practices have been described in
previous reports. /*2+5 Some examples of poor practices used in the past are the
following:

1. By-passing of gas in water spray towers due to improper liquid
seals in the tower. This results in inefficient scrubbing.

2. Operating the plant without addition of lime to the scrubbing
medium. In a recirculating water scrubbing system the fluoride content of the