EPA-600/2-76-114
May 1976
Environmental Protection Technology Series
TROUGH CREEK LIMESTONE BARRIER
INSTALLATION AND EVALUATION
Industrial Environmental Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into five series. These five broad
categories were established to facilitate further development and application of
environmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The five series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
This report has been assigned to the ENVIRONMENTAL PROTECTION
TECHNOLOGY series. This series describes research performed to develop and
demonstrate instrumentation, equipment, and methodology to repair or prevent
environmental degradation from point and non-point sources of pollution. This
work provides the new or improved technology required for the control and
treatment of pollution sources to meet environmental quality standards.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.
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EPA-600/2-76-114
May 1976
TROUGH CREEK LIMESTONE BARRIER
INSTALLATION AND EVALUATION
by
S. Curtis Yocum
Africa Engineering Associates, Inc.
Huntingdon, Pennsylvania 16652
Project No. 14010 FWW
Project Officer
John F. Martin
Resource Extraction and Handling Division
Industrial Environmental Research Laboratory
Cincinnati, Ohio 45268
U.S. ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF RESEARCH AND DEVELOPMENT
INDUSTRIAL ENVIRONMENTAL RESEARCH LABORATORY
CINCINNATI, OHIO 45268
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DISCLAIMER
This report has been reviewed by the Industrial Environmental
Research Laboratory-Cincinnati, U.S. Environmental Protection Agency,
and approved for publication. Approval does not signify that the
contents necessarily reflect the views and policies of the U.S. Environ-
mental Protection Agency, nor does mention of trade names or commercial
products constitute endorsement or recommendation for use.
ii
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FOREWORD
When energy and material resources are extracted, processed, converted,
and used, the pollutional impact on our environment and even on our
health often requires that new and increasingly more efficient pollution
control methods be used. The Industrial Environmental Research Laboratory -
Cincinnati (IERL-CI) assists in developing and demonstrating new and
improved methodologies that will meet these needs both efficiently and
economically.
The Trough Creek Limestone Barrier Installation and Evaluation
Project was undertaken to explore the feasibility of providing a low
cost treatment method for abatement of pollution caused by acid mine
drainage. This report summarizes the findings of a study on the performance
of limestone barriers placed in a stream channel to effect neutralization
of acidity. The work presented augments other types of mine drainage
treatment studies performed by the Extraction Technology Branch which
involve elaborate handling and pumping mechanisms. Results obtained
here will especially benefit state and local agencies charged with
clean-up of acid streams. The guidance presented in this report helps
to define areas where limestone barriers are feasible and to outline
their construction details. Although the use of limestone barriers is
severly limited by stream quality and flow characteristics, the method
is an effective alternative given the correct conditions.
David G. Stephan, Director
Industrial Environmental Research Laboratory
Cincinnati
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ABSTRACT
Six prototype crushed limestone barrier installations were constructed
in Trough Creek in South Central Pennsylvania to demonstrate the neutral-
izing ability of this type structure in low-iron acidic streams. The
project included a stream gaging and sampling program to evaluate the
effectiveness of limestone barrier performance under actual stream con-
ditions, and to assess the adequacy of design relationships developed
from laboratory research.
Limestone barrier performance was excellent during periods of low stream-
flow, in terms of reducing acidity and raising the pH of the water, but
their effectiveness was marginal at design or average streamflow, and they
were ineffective when high runoffs were experienced. Limestone barrier
performance deteriorates after the structures are initially constructed
and placed in operation, because progressive accumulations of sediment
clog interstices between the stones, which lessens the hydraulic conduc-
tivity of the barriers, and surfaces of the stones become coated with
silt, which causes a reduction in reactivity of the reagent (limestone)
with flowing acidic water. The design of limestone barriers should take
these factors into account, and the units should be sized sufficiently
large to overcome this deficiency.
Silted limestone barriers can be restored to porous filtering beds, ap-
proximately equal in performance to initial efficiency, by washing and
rehandling the crushed limestone materials.
This report was submitted in fulfillment of Project Number 14010 FWW by
the Commonwealth of Pennsylvania, Contract No. CR-105, and was prepared
by Africa Engineering Associates, Inc., of Huntingdon, Pennsylvania 16652
under the partial sponsorship of the Environmental Protection Agency.
The work was completed February 15, 1975.
iv
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CONTENTS
Disclaimer
Foreword
Abstract
List of Figures
List of Tables
Acknowledgments
Sections
I Conclusions
II Recommendations
III Introduction
IV Limestone Barrier Design
V Construction of Limestone Barriers
VI Flood Damages - Reconditioning and Repairs
VII Stream Sampling and Limestone Analysis
VIII Limestone Barrier Performance
IX References
X Appendix
Technical Report Data
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vii
viii
1
3
4
10
28
38
46
65
72
73
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FIGURES
No. Page
1 Project Location 5
2 Limestone Barrier Sites 8
3 Limestone Barrier Construction Details - Site No. 1 22
4 Limestone Barrier Construction Details - Site No. 2 23
5 Limestone Barrier Construction Details - Site No. 3 24
6 Limestone Barrier Construction Details - Site No. 4 25
7 Limestone Barrier Construction Details - Site No. 5 26
8 Limestone Barrier Construction Details - Site No. 6 27
9 Completed Limestone Barriers - Site No. 1 30
10 Completed Limestone Barriers - Site No. 2 31
11 Completed Limestone Barriers - Site No. 3 32
12 Completed Limestone Barriers - Site No. 4 33
13 Completed Limestone Barriers - Site No. 5 34
14 Completed Limestone Barriers - Site No. 6 35
15 Flood Damages - Limestone Barriers - Site No. 2 39
16 Flood Damages - Limestone Barriers - Site No. 3 41
17 Flood Damages - Limestone Barriers - Site No. 4 42
18 Sampling Points and Gaging Station - Site No. 1 47
19 Sampling Points and Gaging Station - Site No. 2 48
20 Sampling Points and Gaging Station - Site No. 3 49
21 Sampling Points and Gaging Station - Site No. 4 50
22 Sampling Points and Gaging Station - Site No. 5 51
23 Sampling Points and Gaging Station - Site No. 6 52
24 Performance of Limestone Barriers - Site No. 1 59
25 Performance of Limestone Barriers - Site No. 2 60
26 Performance of Limestone Barriers - Site No. 3 61
27 Performance of Limestone Barriers - Site No. 4 62
28 Performance of Limestone Barriers - Site No. 5 63
29 Performance of Limestone Barriers - Site No. 6 64
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TABLES
No. Page
1 Site Locations - Trough Creek Limestone Barriers 11
2 Design Flows - Trough Creek Limestone Barriers 15
3 Design Acid Loadings - Trough Creek Limestone Barriers 16
4 Valentine Limestone Analysis 17
5 Quantity of Limestone Provided - Trough Creek
Limestone Barriers 18
6 Chemical Analysis of Crushed Limestone 36
7 Sieve Analysis of Crushed Limestone 36
8 Construction Cost - Trough Creek Limestone Barriers 37
9 Reconditioning and Repair Costs
Limestone Barrier Flood Damages 45
10 Limestone Analysis - Basket No. 2 55
11 Limestone Analysis - Basket No. 6 55
12 Limestone Analysis - Basket No. 8 56
13 Limestone Analysis - Basket No. 9 56
vii
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ACKNOWLEDGEMENTS
Sincere appreciation is expressed to Professor R. Rupert Kountz
(deceased), former professor of Sanitary Engineering and a Director of
the Institute for Research on Land and Water Resources at The Pennsyl-
vania State University, for technical support and guidance offered dur-
ing the planning phase of this project.
The cooperation and continuing support of the personnel of the Pennsyl-
vania Department of Environmental Resources (formerly the Department
of Mines and Mineral Industries) in implementing and administering the
work under this project is gratefully acknowledged.
Gratitude is expressed to Dr. A. J. McDonnell and Research Assistant
F. H. Pearson at the Institute for Research on Land and Water Resources,
The Pennsylvania State University, for cooperation extended during the
course of the project.
The support, guidance and assistance by the Environmental Protection
Agency project officers were greatly appreciated.
viii
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SECTION I
CONCLUSIONS
Research in the late 1960's at The Pennsylvania State University indica-
ted the feasibility of placing barriers of crushed limestone in streams
to effect reduction of acidity, and it was recommended that limestone
barrier neutralization should be demonstrated in selected prototypes.
Trough Creek, which is located in South Central Pennsylvania, was pollu-
ted with acid mine drainage in the upper reaches of the watershed.
This stream was selected for prototype limestone barrier installations
at six sites in the watershed because iron and sulfate concentrations of
the water were low, except at one location where the iron concentrations
were in the neighborhood of 30 mg/1.
Alternate schemes for channelling stream flow, along with different
structural configurations and barrier shapes, were incorporated in the
design at the various installations so that an assesment could be made
under actual stream conditions of the most effective type limestone bar-
rier for reducing the mineral acidity of the water.
During the course of the sampling and analysis portion of the Project,
severe flooding (Tropical Storm Agnes in 1972) was experienced in the
watershed causing damage to completed limestone barriers. Selected bar-
riers were reconditioned, repaired, and restored to approximate original
condition.
The sampling and analysis program was authorized to evaluate the per-
formance of the limestone barriers under actual stream conditions, and
to determine the adequacy of design relationships developed from labora-
tory research. An evaluation of the performance of the Trough Creek
Limestone Barriers, based on results of the sampling program and obser-
vations noted in the field, indicates the following:
1. Neutralization of stream acidity can be accomplished by place-
ment of limestone barriers in a stream channel.
2. Limestone barrier performance for the Trough Creek Project did
not meet theoretical efficiency.
3. Although barrier performance was excellent during periods of
low stream flow, in terms of reducing acidity and raising the
pH of the water, their effectiveness was marginal at average
stream flow, and they were completely ineffective during per-
iods of high runoffs.
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4. Limestone barrier performance was more efficient at installa-
tions where the barriers were long, continuous structures and
stream flow patterns were diverted by horizontal or vertical
baffles than it was for the short, multiple unit installations
set in series in the main channel.
5. Limestone barriers are most efficient when they are intially
installed, or after they have been reconditioned.
6. There is a reduction in limestone reactivity that results in
deterioration of barrier performance after the structures have
been in service for some time following initial construction,
and again after they have been reconditioned.
7. The rate of deterioration of limestone barrier performance is
apparently due to two major factors:
(a) Siltation whereby sediment accumulations of
either silt or iron sludges clog interstices
of stones, and
(b) Coating of the surfaces of the stones with
silt or iron hydroxides.
In view of the deficiencies in performance of the limestone barriers on
the Trough Creek Project, it is questionable whether it is feasible to
attempt to provide in-stream limestone barriers exclusively as the treat-
ment method for area-wide mine drainage pollution abatement, even though
the chemical characteristics of the acid waters appear suitable to
treatment with limestone. Rather, it is believed that construction of
limestone barriers in conjunction with other watershed improvements,
such as backfilling strip mined areas, replanting and possibly some mine
sealing, would be a more practical approach to regional mine drainage
pollution abatement, where the watershed areas and runoff characteristics
are similar to those of Trough Creek.
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SECTION II
RECOMMENDATIONS
The process of in-stream neutralization of acid mine drainage by lime-
stone barriers should be limited to waters having very low iron con-
centrations. For the Trough Creek Project, limestone reactivity was
apparently unaffected by armoring of the surfaces of the stones with
iron hydroxides where the iron concentration of the raw water was ap-
proximately 1 mg/1. At one of the barrier installation sites the iron
concentration was approximately 30 mg/1, and accumulations of iron
sludges in the limestone bed caused almost complete deterioration of
barrier performance within a period of three months. Additional re-
search could possibly establish the maximum permissible iron concentra-
tion for satisfactory limestone barrier treatment of acid mine drainage.
In the design of limestone barriers, acknowledgment must be made of the
fact that where watershed conditions are such that muddy and silt-laden
streamflows will be experienced, sediment accumulations will progres-
sively seal the limestone beds, and the surfaces of the stones will
become coated with silt. These conditions will result in a reduction in
limestone reactivity and barrier performance will deteriorate below
theoretical efficiency. The following recommendations are offered in
this regard:
1. The designer should size the units sufficiently large
to overcome this deficiency.
2. A maintenance program should be established to period-
ically recondition the barriers to restore them to
approximate original condition so that barrier perfor-
mance will not deteriorate below required efficiency.
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SECTION III
INTRODUCTION
GENERAL
Acid mine drainage has long been a pollutant in coal mining areas with
the resultant elimination of most aquatic life in streams, together with
the attendant problems of prevention of natural bio-oxidation of organic
wastes, increased pollutional loadings in receiving waterways, and high
treatment costs when water is withdrawn for human use. In the United
States the public has recognized the ruinous capacity of coal mine drain-
age, and laws have been enacted to force the coal industry to treat mine
drainage before discharge to natural watercourses. However, there are
thousands of abandoned mines in the coal fields that continue to gener-
ate acid mine water that discharges directly, without any degree of
treatment, to small streams and tributaries. In many of these waters
the acidity is less than 100 tng/1, and the iron content is low.
In the late 1960's the Pennsylvania Department of Mines and Mineral
Industries (now the Pennsylvania Department of Environmental Resources)
became very much interested in research conducted at The Pennsylvania
State University in the field of neutralization of acids by percolation
of synthetic iron-free acid waters through beds of crushed limestone.
d'Laboratory results of these studies indicated that 100 mg/1 of
acidity could be significantly reduced by percolation of the water
through limestone barriers of short length.
Trough Creek, which is located in South Central Pennsylvania, was
selected for a prototype limestone barrier installation project, because
the acid waters in the upper reaches of this stream exhibited chemical
characteristics similar to the synthetic waters used in the laboratory
studies and appeared to be suitable for treatment with crushed limestone.
(For location - see Figure 1.)
A mine drainage pollution abatement program for Trough Creek had been
estimated by the Commonwealth of Pennsylvania to cost in excess of 1.2
million dollars, with average annual maintenance costs of approximately
one-hundred thousand dollars. This program would have included deep
mine sealing, backfilling, channel improvement and treatment by lime
neutralization of the remaining pollution load. Because of the low iron
and sulfate concentrations of the waters of Trough Creek, it was believed
that the possibility of reduction of the mineral acidity of the stream
with limestone should be pursued, and the Pennsylvania Department of
Mines and Mineral Industries engaged the Firm of Africa Engineering
Associates, Inc., of Huntingdon, Pennsylvania, to provide consulting
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PENNSYLVANIA
m
o
O
o
PROJECT AREA
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engineering services in connection with the investigation and proposed
project. Based on the aforementioned research work performed at The
Pennsylvania State University, together with watershed investigations
conducted by the Commonwealth of Pennsylvania, and field observations,
the consultants found it feasible to construct limestone barrier in-
stallations at six locations in the headwaters of the basin.
The preliminary engineering estimate of the cost of construction of the
Trough Creek Limestone Barrier Installation Project was $172,000. It
was felt that if the limestone barriers were successful in reducing
stream pollution from acid mine water drainage in Trough Creek, the
process could be the key to low-cost treatment of similar polluted
streams in other parts of the Commonwealth of Pennsylvania and the
Nation.
PURPOSE AND SCOPE
The purpose of this investigation and study is to evaluate the effec-
tiveness and performance of the Trough Creek prototype limestone barrier
installations. The evaluations of the barriers developed herein are
based on the results of stream gaging and sampling, analyses of selec-
ted limestone samples placed in the barriers, and field observations of
the completed structures under actual stream conditions during the study
period. The purpose also is to assess the adequacy or inadequacy of
the design based on the degree to which the barriers demonstrated their
ability of reducing the mineral acidity in the stream in relation to
performances expected from laboratory research studies.
This report includes a background summary and discussion of the engineer-
ing design of the limestone barriers, including site selections, and
comments regarding construction. During the course of the construction
phase of the Project the barriers experienced severe flooding conditions
in June 1972 as a result of Tropical Storm Agnes, and additional work
was authorized by the Commonwealth of Pennsylvania to repair and re-
condition some of the barriers. Included as supplementary information
to this report is a tabulation of construction costs of the original
project, together with unit costs of reconditioning and repairing lime-
stone barrier damages occasioned by the June 1972 flood.
LOCATION AND GENERAL BACKGROUND INFORMATION
The headwaters of Trough Creek begin in Bedford, Fulton and Huntingdon
Counties in South Central Pennsylvania. The area has had extensive
deep and surface bituminous mining operations in the Broad Top Coal
Field. The surface mining contributed greatly to the pollution loads
from abandoned deep mines by diversion and interception of surface
water. The water quality problem in the stream is that of acid. Gen-
erally, the iron concentrations are less than 1 mg/1, with corresponding
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low concentrations of sulfate. Manganese and aluminum are not present
except for minute quantities. The stream is devoid of fish life in the
upper reaches due to mine drainage. Trough Creek is a tributary to the
Raystown Branch of the Juniata River, which is a sub-basin of the
Susquehanna River. Trough Creek initially follows a northeasterly and
northwesterly circuitous route. At its mouth, the stream bed is Eleva-
tion 670, U.S.G.S. Datum. The total length of Trough Creek is approxi-
mately 48 kilometers (30 miles), and the watershed is mountainous with
narrow valleys flanked with steep hills with some widening of the basin
in the vicinity of Little Trough Creek. The stream flows through shale
and sandstone formations which contain the previously mentioned bitumi-
nous Broad Top Coal Field. The average stream profile is 5.2 meters
per kilometer (27.2 feet per mile). The annual precipitation ranges
between 89 and 114 centemeters (35 and 45 inches).
The Project received its initial impetus from the conservation sub-
committee of the Huntingdon County Planning Commission. Finances for
construction of the Project were provided from the $500 million bond
issue previously passed by the Pennsylvania Legislature to support
"Operation Scarlift" in the Commonwealth.
CONSTRUCTION PHASE AND SAMPLING PROGRAM
The limestone barriers were constructed at six sites in the upper area
of the Trough Creek Watershed (see Location Map - Figure 2). Construc-
tion of the limestone barriers was started at Site No. 1, the uppermost
site in the watershed, on July 27, 1970 and progressed downstream. All
work under the original contract was completed on November 26, 1971.
Extra work, including placement of additional stone rip-rap along creek
banks, limestone media replacement, and heavy rock fills, was authorized
after completion of the original contract, and this work was completed
in May 1972. In June 1972 severe flooding occurred throughout the
watershed as a result of Tropical Storm Agnes, causing scouring of the
crushed limestone materials, siltation, some erosion at creek banks,
and movement of some of the rock fills on the downstream faces of the
barriers which were used to contain the crushed limestone. At Site
Nos. 1, 2 and 4 flood damages were repaired and the barriers restored to
approximate original condition. This work was started in September 1972
and completed in December 1972 as an extension of the original contract.
The stream gaging and sampling to evaluate the effectiveness of the
barriers began in October 1970 before any limestone had been placed, and
continued through August 1974. During that period, the limestone bar-
riers were constructed and water samples were collected for analysis
on a monthly basis. The stream sampling program consisted of collecting
water samples upstream and downstream from the barriers at the various
installations and recording rate of stream flow. Selected samples of
limestone were placed in the barriers and periodically removed, weighed
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FIGURE 2-LIMESTONE BARRIER SITES
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and replaced to attempt to determine loss of weight of limestone, as a
function of time.
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SECTION IV
LIMESTONE BARRIER DESIGN
GENERAL
The basis of design of the Trough Creek Limestone Barriers was the afore-
mentioned research data that was developed in the late 1960's at The
Pennsylvania State University, which formulated inter-relationships be-
tween acid concentrations, rate of neutralization, stone size, and
stream velocity.
In the design of the limestone barriers, consideration was given to the
possibility of siltation of the crushed limestone materials and scouring
during periods of high stream flow. It was recognized that either of
these conditions could render the installations ineffectual in terms of
their ability to reduce the mineral acidity of the stream; however, it
was also noted at that time that the proposed project to be undertaken
was somewhat experimental in nature, and that the data to be derived
therefrom could provide valuable information in the design of future
installations of similar types, if the process proved practicable.
Generally, the limestone barrier structures are miniature porous dams,
set within the stream channel, and consist of cores of crushed lime-
stone contained by heavy rock fills on the upstream and downstream
faces.
WATERSHED INVESTIGATION AND SELECTION OF LIMESTONE BARRIER SITES
Prior to retaining the consultant for engineering design and prepara-
tion of drawings and contract documents for construction of the Trough
Creek Limestone Barriers, the Deparment of Mines and Mineral Industries
of the Commonwealth of Pennsylvania conducted an investigation of mine
drainage throughout the watershed in April and May 1968. This investi-
gation included stream gaging and water sampling of the stream, tribu-
taries, and at sources of mine seepage.
The watershed investigation conducted by the Commonwealth of Pennsyl-
vania indicated that Trough Creek was considered to be alkaline from
Trough Creek State Park to its confluence with the Raystown Branch of
the Juniata River near Marklesburg, Pennsylvania, and that it was con-
sidered to be acid for approximately 22.5 kilometers (14 miles) in the
upper reaches. The farthermost downstream point of discharge of acid
mine drainage to Trough Creek was found to be the overflow of an aban-
doned drift mine, hereinafter described as Limestone Barrier - Site
No. 5.
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Except for the overflow discharge from the abandoned mine at Site No. 5,
results of chemical analyses of water samples collected throughout the
acid mine discharge areas during the watershed investigation showed
that the pH range of the waters of Trough Creek and the Run leading from
Broad Top City varied between approximately 3.2 and 5.4; acidity varied
between approximately 5 and 22 mg/1; sulfates varied between approxi-
mately 20 and 40 mg/1; and (total) iron concentrations were generally
less than one mg/1. The concentrations of pollution loads from the
overflow discharge at the abandoned mine at Site No. 5 were found to be
approximately 270 mg/1 of acidity and 30 mg/1 total iron. However, the
rate of flow of the abandoned mine discharge was quite low in comparison
to the flow in Trough Creek.
On the basis of the watershed investigation, field inspections, and con-
sultations with the research personnel at The Pennsylvania State Univer-
sity, six (6) sites were selected in the upper area of the Trough Creek
watershed for limestone barrier installations. These Sites are briefly
described in Table 1, and are shown on Figure 2.
Table 1. SITE LOCATIONS - TROUGH CREEK LIMESTONE BARRIERS
SITE NO.LOCATION AND DESCRIPTION
1 Trough Creek - Approximately 183 meters (6001) upstream
from Village of Woodvale at the spillway of an abandoned
reservoir.
2 Trough Creek - Robertsdale - 274 meters (900') more or less,
upstream from bridge at Post Office.
3 Trough Creek - 0.8 kilometers (0.5 mile) more or less,
north of Robertsdale at junction of Trough Creek and tribu-
tary from Broad Top City.
4 Trough Creek - 3 kilometers (2 miles) more or less, north
of Robertsdale at Village of Cooks at junction of Trough
Creek and small tributary. Barrier to be located immediate-
ly downstream from bridge on Route 994.
5 Tributary draining to Luciana Bottoms, approximately 3 kilo-
meters (2 miles) south of Cassville. Barrier to be located
at drainage outlet of old Jacobs Mine.
6 Trough Creek - Upstream from bridge where Trough Creek
crosses L.R. 31094.
In selecting the limestone barrier sites, priority was given to accessi-
bility and close proximity to existing roadways for economical
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construction and maintenance. Also of primary concern in the selection
of barrier locations was topography in the areas adjacent to the proposed
sites. Consideration was given to the possibilty of ponding of a few
feet additional depth of water upstream from the barriers, and it was
believed that minimum property damage would result from the stream ob-
structions at the sites selected.
ENGINEERING DESIGN - LIMESTONE BARRIERS
General guidelines for the design of the Trough Creek Limestone Barriers
were established as an outgrowth of preliminary conferences with Univer-
sity research personnel, Commonwealth of Pennsylvania Officials, and
the consultant, as follows:
1. Design flows through the barriers should be determined on
the basis of approximately one-hundred twenty-five (125%)
percent of the computed average stream flow.
2. Design acid loadings, in terms of pounds per day, at the
various limestone barrier sites should be determined on
the basis of approximately one-hundred twenty-five (125%)
percent times computed loadings at average stream flow.
3. Crushed limestone should be furnished in sufficient quantities
to provide for a theoretical 5-year limestone consumption or
replacement program, based on the specified calcium carbonate
content of limestone.
4. Although the use of graded limestone of the smaller sizes
(2.5 cm or 1 inch in size) was recommended in the research
studies because of the greater surface (contact) area and
resultant higher neutralization rates, it was decided to use
larger stone sizes (6.35 to 10.16 cm or 2 1/2 to 4 inches) in
the barriers to be erected in the stream because the larger
stones would provide greater stability and be less susceptible
to washing and scouring during periods of high stream flow. At
Site No. 5, where the flow was known to be low and relatively
constant, it was decided to use the smaller stone size.
5. The limestone barriers at Site No. 6, and to some extent the
barriers at Site No. 4, should be erected to provide additional
insurance if upstream installations failed or would not provide
expected degree of treatment.
6. Limitations of the Pennsylvania Department of Forests and
Waters (now Department of Environmental Resources) regarding
encroachments and stream obstructions in the waters of the
Commonwealth must be strictly adhered to.
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7. Inasmuch as a follow-up water sampling and stream gaging
program to evaluate the effectiveness of the limestone
barrier installations was contemplated during the planning
phase of the project, it was decided that measuring flumes
of constant cross-section should be installed in the stream
for the purpose of measuring stream flow by the velocity-
area method.
Detailed design of the Trough Creek Limestone Barriers was based on in-
ter-relationships of stone size, rate of flow, barrier length, superfi-
cial velocity, retention time, and initial acidity. The six working
equations that were developed as a result of the research in the late
1960?s at the Pennsylvania State University are as follows:
U = 0.353D + 0.566Q - 0.0292L + 1.060
T = 0.265DJ0-366 V°'477Lp 1>35
K = 0.55Cr0-1V0-74D-0'84
Cf = C. (1-K)T
H = -0.580D + 0.5840 + 0.0376L + 1.521
s = o.4i7rr°-931Q °-921L -0-562
p p p
where, U = average superficial velocity, fps
D = stone size, inches
P
Q = flow rate, cfs/ft
P
L = barrier length, feet
P
T = retention time, seconds
K = fractional acid reduction, sec-1
C^ initial acidity, mg/1
Cf= final acidity, mg/1
H = head water depth, feet
S = water surface slope
Hydraulic profiles, computed from the above relationships, were
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Investigated under varying rates of flow through the barriers. Where
necessary, the slopes of stream beds were altered to provide ample head
between the upstream and downstream limits so that the hydraulic gradient
at design (average x 1.25) flow was uninterrupted through the barriers.
Determination of Design Flows
The Pennsylvania Department of Forests and Waters (now the Pennsylvania
Department of Environmental Resources) maintained a stream gaging sta-
tion for the period 1930 to 1957 on Great Trough Creek at a highway
bridge, 0.8 kilometers (0.5 miles) upstream from the confluence of Great
Trough Creek and the Raystown Branch of the Juniata River, Information
contained in the 1966 edition of the Pennsylvania Department of Forests
and Waters "Bulletin No. 1, Water Resources Bulletin, Pennsylvania
Streamflow Characteristics - Low Flow and Flow Duration" for the Great
Trough Creek Gaging Station was the basis for determining design stream
flows at the various limestone barrier sites.
Following is a tabulation of pertinent data relative to stream flow
characteristics at the Great Trough Creek Gaging Station:
Drainage Area 219.1 km2 (84.6 sq. mi.)
Average Discharge (27 years) 2.7 m^/s (95.1 cfs)
Max. Discharge (Mar. 17, 1936) 238 m3/s (8,400 cfs)
Min. Discharge (3 occasions) 0.02 m3/s (0.6 cfs)
By interpolation from the Duration Table of Daily Flow in the Bulletin,
the average (27 year) discharge was exceeded 29.4 percent of the time.
Design (average x 1.25) flows for the limestone barriers were computed
by assuming uniform runoff conditions throughout the watershed, deter-
mining the contributary drainage area above each site by planimeter on
U.S.G.S. Maps, and by applying an average discharge rate of 1.232 x 10~2
m3/s per square kilometer (2.7 m3/s-f- 219.1 km2) or 1.124 cfs/sq. mile
(95.1 cfs -f 84.6 sq. mi.). Design Flows are tabulated in Table 2.
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Table 2. DESIGN FLOWS - TROUGH CREEK LIMESTONE BARRIERS
(1) C2) (3)
Drainage Average Design Cumulative Design
Area (Sq. Mi.) Flow (cfs) Flow (cfs) Flow (cfs)
1 6.05 6.8 8.5 8.5
2 4.10 4.6 5.8 14.3
3 3.45* 3.9* 4.9* 19.2*
4 3.66 4.1 5.1 24.3
6 7.06** 7.9** 9.9** 34.2**
NOTE: To convert square miles to square kilometers, multiply square
miles x 2.59. To convert cfs to m3/s, multiply cfs x 0.02832.
(1) Incremental contributory drainage area upstream from each
site
(2) Computed - 1.124 cfs/sq. mi.
(3) 1.25 x computed average flow
*Includes Run from Broad Top City on which Limestone Barrier
No. 3-C was erected. The design flow for this Barrier was
3.0 cfs, and is included in the cumulative (19.2 cfs) flow
for Barriers Nos. 3A and 3B.
**Includes watershed area of 0.22 sq. mi. above Site No. 5,
which drains to Trough Creek between Sites Nos. 4 and 6.
Design Flow of 0.4 cfs used for overflow at abandoned mine
at Site No. 5.
Design Acid Loadings - Limestone Barriers
Acid loadings used for design at the various limestone barrier sites
were determined from results of analyses of the preliminary water
sampling and stream gaging investigations of the watershed.
The stream flows that were recorded at the time of the watershed investi-
gation were slightly different than the computed design average flows;
however, the acid concentrations of water samples collected at the pro-
posed limestone barrier sites were used to determine the design acid
loadings. As previously mentioned, the design acid loadings were deter-
mined by increasing computed acid loadings by approximately 25 percent
at all sites, except that the barriers to be erected at Site Nos. 4 and
6 were to be furnished primarily to provide additional insurance if
15
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upstream installations failed to yield expected degree of treatment.
Table 3 shows the design acid loadings at the various limestone barrier
sites.
Table 3. DESIGN ACID LOADINGS - TROUGH CREEK LIMESTONE BARRIERS
(3)
(1) (2) 5-Year Acid
Site Computed Acid Design Acid Design Loading
No. Loading (Ibs/day) Loading (Ibs/day) (Ibs. x 103)
1 733 900 1,650
2 42 50 100
3A & 3B* 130 165 300
3C** 68 85 150
4 50 50 100
5 584 730 1,330
6 — ~ —
Totals 1,607 1,980 3,630
(1,865 Tons)
(1,693 Metric
Tons)
NOTE: To convert pounds (Ibs) to kilograms, multiply
pounds x 0.4536.
*Limestone Barriers in Trough Creek
**Run from Broad Top City
(1) Incremental acid loading between each site
(2) 1.25 x computed load
(3) 5-year acid loading shown to nearest 50 x 103 pounds
Crushed Limestone
Since the Trough Creek Limestone Barrier Installation Project was a
prototype project undertaken as a result of research, it was deemed
necessary that the limestone materials to be furnished for the barriers
should not only be effective as a neutralizing agent, but also it was
believed desirable that the materials should be similar in chemical com-
position to those used in the research studies. The crushed limestone
that was used for the University research work at State College, Pennsyl-
vania, was Valentine Limestone, and was obtained from the Appalachian
Stone Quarry (Division of Martin Marietta). This quarry is located at
Pleasant Gap, Pennsylvania, approximately 14.5 kilometers (9 miles)
16
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northeast of the University; however, the quarry is located approxi-
mately 105 kilometers (65 miles) from the Trough Creek Project area. A
typical analysis of Valentine Limestone was furnished by the supplier
and is shown in Table 4.
Table 4, VALENTINE LIMESTONE ANALYSIS
Substance Percent by Weight
CaC03 96.800
MgC03 1.630
0.800
0.500
P 0.003
S 0.035
During preparation of the Contract Specifications for construction of
the Trough Creek Limestone Barrier Installation Project an effort was
made to locate a suitable source of limestone (high in calcium carbon-
ate) close to the Project area to minimize haulage and keep construction
costs as low as possible. However, it was found that limestones in
active quarries in Central Pennsylvania near the Project area were dolo-
mitic limestones, high in magnesium carbonate (approximately 30 to 40
percent by weight), and according to previous research studies, would
probably not be as effective a neutralizing agent as the limestones
from the Appalachian Stone Quarry. With the foreknowledge that con-
struction costs would be somewhat higher than originally expected be-
cause of long hauls for delivery of materials, the Contract Specifica-
tions stipulated that the calcium carbonate content of the limestone
to be furnished for the barriers shall not be less than 95 percent by
weight.
As previously noted under the general guidelines for design of the
barriers, it was decided that crushed limestone should be furnished in
sufficient quantities to provide for a theoretical 5-year replacement
based on the calcium carbonate content of the limestone; and that the
barriers at Site No. 6, and to some extent the barriers at Site No. 4,
should be erected to provide additional insurance if upstream installa-
tions failed or would not provide the expected degree of treatment.
Also, the size and shape of the barriers was governed by site topography
and limitations of the Commonwealth of Pennsylvania regarding stream
obstructions. Table 5 shows a tabulation of the theoretical 5-year
quantity of limestone required at each site compared to the amount
actually provided. The amounts provided, as shown in the Table, are
quantities computed from the detailed contract drawings.
17
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Table 5. QUANTITY OF LIMESTONE PROVIDED TROUGH CREEK LIMESTONE BARRIERS
(1) (2) (3)
5-year Acid Limestone Required Quantity of
Site Loading 5-year Replacement Limestone Provided
No. (Ibs. x 1Q3) (c.f.) (c.f.) t
1 1,650 19,470 13,300
2 100 1,180 A,600
3 450 5,310 6,100
4 100 1,180 15,300
5 1,330 15,700 16,800
6 - - 29,000
NOTE: To convert pounds (Ibs.) to kilograms, multiply pounds x 0.4536
To convert cubic feet (c.f.) to m^, multiply c.f. x 0.02832
(1) Reference Table 3
(2) Computed quantity based on the following limestone properties:
96% CaC03
Specific Gravity =2.7
53% Solids
(3) Determined from detailed Contract Drawings
Although the quantity of limestone furnished at Site No. 1 was less
than the theoretical 5-year computed quantity, it was believed to be
adequate because it did provide limestone for a calculated 3.4 year sup-
ply, and surplus materials were being furnished at other downstream
sites.
Gaging Flumes - Measurement of jtream Flow
Gaging flumes of constant cross-section were proposed at each site so
that during the sampling program the rate of flow could be measured
by the velocity-area method in the main channel and tributaries. The
gaging flumes were proposed to be grouted stone rip-rap construction,
7.6 meters (25 feet) in length, and the slope of the invert to be 0.40
percent. The cross-sections of the flumes at the various sites were
sized on the basis of the following design criteria.
1. Design (flood) flows to be computed from upstream
contributary drainage areas and proportioned to the
maximum discharge rate of 238 m^/s (8400 cfs) for the
watershed having a drainage area of 219.1 square
18
-------
kilometers (84.6 sq. mi.) and which was recorded March 17,
1936 at the Great Trough Creek Gaging Station.
2. Depth of water in the proposed flume channels to be
approximately 0.3 meters (one foot) at computed average
stream flow.
3. Use n = 0.015 in the Kutter formula for grouted stone
masonry, and n = 0.013 for vitrified clay channel pipes.
All flumes were sized to accomodate design flood flows. Wherever pos-
sible, the flumes were installed upstream from the barriers such that
the profile of the hydraulic gradient of stream flow through the flumes
would be unaffected by any water build-up on the upstream faces of the
barriers at design (average x 1.25) flow. Where topography dictated
that flumes be installed downstream from the barriers, they were posi-
tioned low enough so that the profile of the hydraulic gradient of
stream flow through the barriers would be unaffected by flow through the
flumes at computed average streamflow.
Comments Regarding Design
The undertaking of construction of the prototype Trough Creek Limestone
Barriers for the purpose of neutralizing acid mine drainage by the pro-
cess of in-stream treatment with crushed limestone was the first such
endeavor for an entire watershed pollution abatement project where the
range of stream flow was of the magnitude of Trough Creek. At the out-
set, it was recognized that there were a number of uncertainties associ-
ated with the project that suggested potential problem areas, such as
possible siltation, erosion, and scouring of the crushed limestone.
Furthermore, it was not known if a certain degree of armoring of the
surfaces of the limestone might occur where the materials remained un-
disturbed for long periods of time, even though the iron concentrations
were low.
In attempting to establish the general guidelines for engineering design
of the Trough Creek Limestone Barriers, acknowledgment was made of the
fact that normally stream sampling in connection with design is more
comprehensive in scope than that performed for this project at the pro-
posed barrier sites. A more extensive preliminary water sampling pro-
gram at the proposed barrier sites may have altered somewhat the design
acid loadings and projected theoretical quantities of limestone required
for 5-year replacement. However, in view of the nature of the uncertain-
ties previously noted,together with the lack of factual information
pertaining to limestone reactivity and barrier performance under actual
stream conditions, it was believed that the additional time that would
be involved in conducting a comprehensive water sampling program at each
site to determine more precisely the design acid loadings was not
19
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justified. It was also believed that any deficiencies in design cri-
teria developed from laboratory research, together with possible detri-
mental physical aspects that would render the barriers ineffective, would
become manifest in the stream sampling, analysis and evaluation project
that would be conducted during and after construction of the limestone
barriers.
Barrier Configurations and Details
Topography in the areas adjacent to the proposed limestone barrier sites,
together with limitations set forth by the Commonwealth of Pennsylvania
regarding channel changes and stream obstructions, dictated to some
degree the configurations of the limestone barriers. Also, it was felt
that different stream flow patterns and barrier shapes should be in-
corporated in the design of the Project to see which scheme proved to be
the most effective under actual stream conditions in reducing the mineral
acidity of the water.
In Pennsylvania it is necessary to obtain a permit from the Department
of Environmental Resources to construct any dam or other water obstruc-
tion, or in any manner to change or diminish the course, current or
cross-section of any stream having a drainage area of more than 1.3
square kilometers (one-half eq. mi.). For the Trough Creek Project a
permit was required for each limestone barrier installation, except at
Site No. 5 where the drainage area above the site was 0.57 sq. km. (0.22
sq. mi.)- General requirements for permit approval for the Trough Creek
Limestone Barriers included the following stipulations:
1. Existing stream channels shall be widened and the stream
beds reshaped in the limestone fill areas. The extended
creek banks shall be lined with heavy rocks to top of
bank on each side of the barriers to prevent erosion dur-
ing periods of high water and scouring stream flow.
2. Limestone barriers shall be constructed to heights not
exceeding 0.9 meters (3 ft.) above existing stream bed
elevation. In this connection, where it was necessary or
desirable to provide limestone fills greater than 0.9
meters in depth, existing stream beds were lowered such
that elevation of the top of the barriers was not more
than 0.9 meters above existing stream bed.
The proposed limestone barriers at Site No. 1 were located at the outlet
end of a shallow abandoned reservoir. The design included horizontal
and vertical baffles to provide an extended contact period for the acid
water with the crushed limestone.
At Site Nos. 2 and 3 where the creek banks were well defined, two bar-
20
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riers at each site were proposed in series in the main channel of
Trough Creek, and one barrier in the Run from Broad Top City at Site
No. 3. The barriers at these sites were approximately 7.6 meters (25
ft.) in length and extended from creek bank to creek bank in the stream
channel. Rock barriers, consisting of large stones placed in the main
channel from creek bank to creek bank, were provided upstream from the
limestone barriers for the purpose of collecting floating debris during
periods of low and average streamflow.
At Sites Nos. 4 and 6 where the creek banks were not well defined, the
design included jetty-type structures to be erected alternately from
each creek bank and extending into the main channel. Additional crushed
limestone, approximately 0.3 meters (one foot) in depth, was provided in
the channel. Horizontal concrete baffle walls and vitrified clay pipe
cross drains were proposed to divert low or average streamflows such
that a longer contact time for neutralization would be afforded. Stil-
ling basins were provided upstream from the limestone barriers to settle
out mud and sediment.
At Site No. 5, the overflow outlet of an abandoned mine, the proposed
barrier simply included clearing, excavation, and completely filling
the outlet area with crushed limestone to a computed depth such that
design flow would be below the surface of the limestone materials.
In March 1970 the Commonwealth of Pennsylvania authorized the advertise-
ment for bids for construction of the Trough Creek Limestone Barrier
Installation Project. Details of the limestone barriers at the various
sites are shown on Figures 3 to 8 inclusive.
21
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<.
SECTION THROUGH BASE LINE
peoTEC-r is
11 ,-^6^^"^'
.//T
riMAL corsroues SHOWH INDICATE
LIMITS OF LIMESTONE FILL MID
FIHISHZD aeadifJG. see DETAIL HT
eiQHT foe EXCAVATION LIMITS
fT
PLAN-LIMESTONE
BAP&EBS A/2* IA * IB
to to o eo
fffr
Figure 3. Limestone Barrier Construction Details—Site No. I
LIMESTONE
B
•
-------
„
PZxW - LIMESTONE
2 A * ^ &
SECTION LIMESTONE BABBIEP N? ^ 5
TRAUSVEPSE SECTION
LIMESTONE
Figure 4. Limestone Barrier Construction Details—Site No. 2
-------
-PLAN-
3A ,36 4 3C ~
vrtff"-' -' „ ,f
L/ME5TOME-
STREAM PROFILE.
SECT/ON - LIMESTONE BA2ZIE2
e > o 2
SCAL£ /f/ffcr
Figure 5. Limestone Barriers Construction Details—Site No. 3
-------
-
-JZQCK FfLL-
LA(D LOOSE
W* ;5£7»«--
S££ 3*£ETa
LIMESTONE BflEZtEZ A/S 4C
Jfit Ei. iSfO.O )
<~m- o f at*w
'•LIMESTONE
P. I. NS. t
X'» W
£ - 33.^1
MS 4 A
(oorroM £i.. isii.c.
PLAN - LIMESTONE BAPPIEP5 N^ 4A. 48 * 4C
m'-aaeei£.a UO.AA
T-aAjrei&es *sos *8f(^
\ FiLL*/tTH U*f£5TOM£ *f£&* 727 ^-
F3
- Ltfi1£3~TO*/£ Ftt± •
-JSOCK ffiL
we {.ease
eOCIC fJLL
LA Jo tocse.
fa.
- BOTTOM El. l£ll.O
SECTION - PROPOSED STREAM CHANNEL
• t m
52
rtfffr
Figure 6. Limestone Barrier Construction Details — Site No. 4
-------
If* °
'-
r
- PLAN -
LIMESTONE BARRIERS N^ 5A t SB
PROFILE - LIMESTONE BhRglER N* SA
NOTE-
Figure 7. Limestone Barrier Construction Details—Site No. 5
-------
-KIP - ^«» CfCfK
/ 6JWK LiHIHG
X-
\
- LIMESTONE BARRIERS A/^
NOTE '•
EXIST G80UMO
7- Htnerj «/ t* t
,ts'~ B*eatta tJo &m
SECTION - PROPOSED STREAM CHANNEL
Figure 8. Limestone Barrier Construction Details—Site No. 6
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SECTION V
CONSTRUCTION OF LIMESTONE BARRIERS
GENERAL
In June 1970 the Contract for "Construction of Limestone Barriers -
Trough Creek Watershed," Contract No. SL-121-1, was awarded by the
Commonwealth of Pennsylvania in the amount of $184,450.00. The work
under the Contract consisted of construction of limestone barrier instal-
lations at six locations in the watershed and included site clearing,
stream channel widening and lowering existing stream beds, and the fur-
nishing and placing of stone rip-rap creek bank linings, grouted stone
rip-rap gaging flumes, concrete masonry, heavy rock fills, piping, and
crushed limestone.
The work was started on July 27, 1970 at Site No. 1, the uppermost site
in the watershed, and progressed downstream. The sequence of construc-
tion of the barriers at the various sites is shown in SECTION VII,
STREAM SAMPLING AND LIMESTONE ANALYSIS, where a correlation is made of
the acidity of the waters of Trough Creek relative to installation of
the barriers. Construction costs for the original contract plus cer-
tain extra work allowances are shown in Table 8 in this Section. A
description of limestone barrier damages caused by flooding in 1972 are
presented in Section VI, together with measures that were adopted for
reconditioning and barrier repairs, and costs of correction.
Construetion Requ irements
All work on Contract No. SL-121-1 was performed on private property
where easement agreements had been previously acquired. The contract
included the usual requirements regarding responsibilities in connection
with ingress and egress over the properties for the purpose of construc-
tion, clean-up, and disposal of waste materials. Limestone barrier
installations were constructed, complete, in consecutive order beginning
at Site No. 1 and the work proceeded downstream to Site No. 6. At each
limestone barrier site all work was completed and stream flow directed
through the barriers before the contractor moved his operations to suc-
ceeding downstream installations. The contract specifications stipulated
that the sequence of such work at each site shall be performed in the
following order:
1. Site clearing, including access roadways, and the removal
and disposal of trees, stumps, brush and general clearing
preparatory to excavation.
2. Excavation, including removal and disposal of all materials
28
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necessary for lowering existing stream beds and relocating
stream channels to the lines and subgrades shown on the con-
tract drawings. The Contractor was required to employ such
protective measures as were necessary to prevent pollution of
the stream with fuels, oils, sediment or other harmful materials.
The Contract required that all excavations be completed before
placement of rolled fills, stone rip-rap, rock fills, concrete
masonry and crushed limestone.
3. Placement of rolled earthen fills.
4. Placement of stone rip-rap on creek banks to prevent bank
erosion. The specifications required that at least 30 per-
cent of the stones for rip-rap shall weigh not less than 90.7
kilograms (200 pounds) and at least 20 percent shall weigh mpre
than 9.1 kilograms (20 pounds).
5. Placement of concrete masonry for cut-offs and baffle walls.
6. Placement of rock fills at the proposed upstream and downstream
faces of the barriers, and at other locations used to confine
and prevent washing of the crushed limestone. The specifica-
tions required that at least 60 percent of the stones for rock
fills shall weigh not less than 90.7 kilograms (200 pounds) and
at least 90 percent of the stones shall weigh more than 9.1
kilograms (20 pounds).
7. Placement of crushed limestone in the barriers was the last
step in the sequence of construction at each site. The speci-
fications required that the limestone materials be stored on
hard and clean elevated surfaces, sloped to the outer edges
to insure proper drainage and to prevent possible accumulations
of mud and silt on the stone surfaces during storage. The
contract also required that the crushed limestone be placed in
the stream as nearly as practicable in its final position.
Bulldozing of limestone materials into place, or the traveling
over previously placed materials with heavy equipment was pro-
hibited. Placement of the crushed limestone on prepared stream
bed surfaces was started at the furthermost point upstream and
proceeded downstream. Table 6 shows a chemical analysis of
the limestone materials furnished for the Trough Creek Project,
and Table 7 shows the sieve analysis of the materials.
Illustrations of the finished limestone barriers, as they appeared shortly
after construction was completed, are shown in Figures 9 to 14 inclusive.
29
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FIGURE 9 - COMPLETED LIMESTONE BARRIERS - SITE No. 1
-------
FIGURE 10 - COMPLETED LIMESTONE BARRIERS - SITE No. 2
-------
FIGURE 11 - COMPLETED LIMESTONE BARRIERS - SITE No. 3
-------
u
—
FIGURE 12 - COMPLETED LIMESTONE BARRIERS - SITE No. ~k
-------
-
FIGURE 13 - COMPLETED LIMESTONE BARRIERS - SITE No. 5
-------
UJ
Ul
. **
'
£
FIGURE 14 - COMPLETED LIMESTONE BARRIERS - SITE No. 6
-------
Table 6. CHEMICAL ANALYSIS OP CRUSHED LIMESTONE
Chemical Substance Percent by Weight
Iron 0.10
Calcium Oxide 55.50
Magnesium Oxide 0.70
Loss on Ignition 42.15
Other 1.55
Calculated from CaO plus MgO
Calcium Carbonate 99.06
Magnesium Carbonate 1.46
Table 7. SIEVE ANALYSIS OF CRUSHED LIMESTONE
Screen Size Percent Passing
10.16 cm (4") 100
6.35 cm (2 1/2") 34
Construction Costs
On November 28, 1971 all work under the original contract was completed,
and the total value of this work was $184,338.60. In February 1972
extra work was authorized at Site Nos. 1, 4, 5 and 6. The extra work
included replacement of approximately 15.3 cu. meters of crushed lime-
stone at Site No. 1, placement of some additional- stone rip-rap on creek
banks at Site Nos. 4 and 6 to help prevent bank erosion, and placement
of heavy rocks and a 60.96 cm (24-inch) grout-filled corrugated metal
pipe (placed approximately perpendicular to channel flow and sloped away
from the creek bank) to act as a deflector and to help prevent scouring
of the crushed limestone in the channel of Limestone Barrier No. 1-B at
Site No. 1. The authorized extra work also included scarifying and re-
distributing the crushed limestone in the barrier at Site No. 5, where
accumulated iron sludges had clogged the voids in the limestone materials
and neutralization of the acid was not being effectuated. The total
value of the extra work was $6,784.00; it was started in April 1972 and
completed in May 1972.
Construction costs for the original project, together with costs for the
extra work authorized in February 1972, are shown in Table 8, and in-
clude a breakdown of quantities of work and materials at the various
sites.
36
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Table 8. CONSTRUCTION COST - TROUGH CREEK LIMESTONE BARRIERS
Contract Iten - Description Unit
Site Clearing (Lump Sum)
Excavation and Disposal C.T.
Rolled Embankment C.T.
Rip Rap Creek Bank Linings S.T.
Grouted Stone Rip-Rap S.T.
Concrete Masonry C.T.
Rock Klls C.T.
12-Inch V.C. Channel Pipe L.F.
18-Inch V.C. Channel Pipe L.F.
2l*-Inch V.C. Pipe L.F.
30-Inch V.C. Pipe L.F.
2U-Inch C.H. Pipe L.F.
Crushed Lines tone C.T.
Quantities - Trough Creek Limestone Barrier Site No.
1
116
80
170
82
10.5
175
-
-
25
-
120
531
2
1,082
171
137
1*
269
-
-
-
-
-
188
3
832
100
36
1ft
7
220
-
-
25
-
-
33U
U
2.U10
U7
ma
169
33
332
-
25
-
138
-
539
5
U56
-
-
1*3
It
15
25
-
-
-
-
688*
6
U.U10
882
U19
203
65
50
-
-
-
276
-
1,076
Total Unit
Quantity Price Amount
$15,000.00 $ 15,000.00
9,306 2.UO 22.33U.UO
1,109 1.60 1,996.20
9l»U 12.00 11,328.00
798 18.00 U*,36U.OO
153.5 80.00 12,280.00
1,577 12.00 18,92ii.OO
25 20.00 500.00
25 2U.OO 600.00
50 30.00 1,500.00
Ullt 18.00 7,152.00
120 30.00 3,600.00
3,356 2U.OO 8o,51*U.oo
* Prior to conpletion of the work the Contractor was authorized to scarify and redistribute
th« lisestoae materials at Slt« No. 5, as iron sludge began to accumulate, for a lump son
price of $700.00, bringing the total cost of vork under the original contract to $191,122.631
Total Value of Work
$190,1*22.60
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SECTION VI
FLOOD DAMAGES - RECONDITIONING AND REPAIRS
GENERAL
In March 1972 heavy rainfall, accompanied by warm weather that melted
deep snow in the Trough Creek Watershed, caused flooding at the lime-
stone barrier sites. Local residents reported these flooding condi-
tions to be the worst in many years in some areas. The spring flooding
and high stream runoffs in March 1972 caused silting of the crushed
limestone at Site Nos. 3, 4 and 6, and creek bank erosion was noted at
Site Nos. 1, 3 and 6. Some scouring of the crushed limeston and dis-
placement of rock fills occurred at Site Nos. 1, 2 and 3.
In late June 1972 severe flooding occurred throughout the watershed as
a result of Tropical Storm Agnes. The extent of damages to the lime-
stone barriers following the June flood was greater than that experi-
enced in March, and included considerable silting of the crushed lime-
stone beds, displacement of heavy rock fills at certain locations, creek
bank erosion, and some scouring of the crushed limestone.
Presented below is a description of the effects of flooding at the
various limestone barrier sites,
Site No. 1. High waters overflowed the horizontal concrete baffle
in Barrier No. 1-B. Silting was noted at the lower end of the
barrier, and some crushed limestone materials were scoured and de-
posited in the grouted stone rip-rap flume. Creek bank erosion
occurred downstream from the flume.
Site No. 2. At Barrier No. 2-B the March 1972 flood caused debris
build-up on the upstream side of barrier, some silting, but very
little scouring of the limestone materials. At Barrier 2-A a few
large stones were displaced on the downstream face of the barrier,
and minor silting and some scouring of the limestone materials were
noted following the March flood.
Damage resulting from the June flood at Site No. 2 included some
movement of heavy rock fills, and the scouring and washing down-
stream of approximtely three-quarters of the limestone materials
in Barrier No. 2-A, and approximately one-half of the limestone
materials in Barrier No, 2-B. Also, considerable deposits of mud
and gravel were noted immediately upstream from Barrier No. 2-B
and the Rock Barrier. (See Figure 15)
38
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_
~
FIGURE 15 - FLOOD DAMAGES - LIMESTONE BARRIERS - SITE No. 2
-------
Site No. 3. The most extensive flood damage was experienced at
this site, where the slope of the stream bed is steeper than at
any of the other limestone barrier sites.
The March flood damages included displacement of a few large stones
in the rock fills on the downstream faces of Barrier Nos. 3-A and
3-B, which are located in the main channel of Trough Creek. As
a result, some scouring and washing downstream of the crushed lime-
stone material occurred. Also, there was evidence of minor silta-
tion of the limestone materials, and creek bank erosion was noted
downstream from Barrier No. 3-A.
The magnitude of the June flood damages at Site No. 3 was greater
than that experienced in March. At Limestone Barrier No. 3-A,
nearly all the limestone materials were scoured and washed down-
stream, and approximately one-half of the heavy rock fills were
displaced. Approximately three-quarters of Limestone Barrier No.
3-B was washed away, including the limestone materials and rock
fills. The limestone materials in the approximate upper two-thirds
of Limestone Barrier No. 3-C were scoured and washed downstream.
(See Figure 16)
Site No. 4. The most serious effect of flooding at this site was
siltation. The effects of both the March and June floods were
similar, except that siltation following the June flood was more
pronounced. Large quantities of mud and silt were deposited in the
stilling basin upstream from the barriers, and also in the main
channel downstream from the barriers. Silt deposits on the bar-
riers and in the limestone filled channel area choked voids and
prevented filtering action through the crushed limestone mater-
ials. (See Figure 17)
Site No. 5. There was no apparent damage to the barrier at this
site from surface runoffs.
Site No. 6. Flood waters at this site caused silting of the bar-
riers, stilling basin and stream channel similar to the conditions
noted at Site No. 4, with the resultant clogging of voids in the
crushed limestone materials. Approximately one-half of the lime-
stone materials in Barrier No. 6-B were washed downstream during
the June flood. There was no apparent scouring of the limestone
materials during the March flood.
40
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FIGURE 16 - FLOOD DAMAGES - LIMESTONE BARRIERS - SITE No, 3
-------
FIGURE 17 - FLOOD DAMAGES - LIMESTONE BARRIERS - SITE No. 4
-------
Reconditioning and Repairs - Limestone Barriers
When flood waters receded in the Trough Creek Watershed following the
June 1972 flood, an assessment of damages was made at each site to de-
termine costs involved in restoring the limestone barriers to approxi-
mately original condition. The total estimated cost of construction
for restoring the barriers at Site Nos. 1, 2, 3, 4 and 6 was $68,080.
In August 1972 the Commonwealth of Pennsylvania approved extra work
expenditures under Contract No. SL-121-1 for restoring the limestone
barriers at Site Nos. 1, 2 and 4. No additional work was authorized
at Site Nos. 3 and 6. The restoration work at Site Nos. 1, 2 and 4
included excavation and disposal of mud and silt deposits, furnishing'
and placing rock fills on the downstream faces of barriers at Site No. 2
and in the channel at Site No. 4, furnishing and placing additional rip-
rap creek bank linings at all three sites, rehandling and washing the
crushed limestone materials remaining in the barriers to remove silt
and restore the barriers to porous filtering beds, furnishing and placing
new crushed limestone to replace materials washed away during the floods,
and seeding ground surfaces adjacent to the barriers to help prevent
soil erosion and washing. All work in connection with reconditioning
and repairs of the limestone barriers was performed during periods of
low stream flow.
The restoration work was started in late September 1972 and completed
in early December 1972. A breakdown of quantities of work and materials
at the various sites, together with unit costs for such work are shown
in Table 9.
The procedures adopted for rehandling and washing the crushed limestone
at each site were as follows:
1. Channels or drainage ways were excavated through the barriers
parallel to streamflow between the downstream and upstream
limits.
2. The silted limestone materials were excavated and stockpiled
on each side of the drainage channels. Equipment used for
this work was a combination dozer with a small backhoe and
front-end loader.
3. The stockpiled silted limestone materials were rehandled,
cleaned and washed with water under pressure, and replaced in
final position in the barriers. A portable pumping unit that
took suction from the stream was used for washing. This unit
was a centrifugal pump with 3-inch suction and 3-inch discharge
pipe connections, driven by a 12-horsepower gasoline engine,
and delivered approximately 100 gallons per minute at a
43
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corresponding total dynamic head of 100 feet. The end of
the 3-inch discharge hose was equipped with a 1 1/2 inch steel
pipe nozzle.
4. New crushed limestone was furnished and placed in the barriers
to finished lines and grades to replace materials washed away
during the floods.
Washing, and the placement of the crushed limestone materials in final
position, was started at the upstream extremities of the barriers at
each site and the operations progressed downstream so that sediment from
washings would not clog or coat the surfaces of previously cleaned
materials.
The reconditioning and repair work that was undertaken at Site Nos. 1,
2 and 4 after the June 1972 flood was successful in restoring these
limestone barriers to porous filter bed structures, approximately equal
in condition to that which existed when they were initially installed.
The washing and rehandling operations thoroughly cleaned the crushed
limestone rock surfaces that had become coated with clay-like materials
and slimes, thus restoring the neutralizing ability of the carbonate
rocks.
44
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Table 9. RECONDITIONING AND REPAIR COSTS - LIMESTONE BARRIER FLOOD DAMAGES
Description
Excavation
Rip-Rap Creek
Bank Lining
Rock Fills
New Crushed
Limestone
Rehandle and Wash
Existing Crushed
Limestone
Seed Ground
Surfaces
Unit
Cu. Yd.
Sq. Yds.
Cu. Yds.
Cu. Yds.
Cu. Yds.
Acre
Quantities - Site No.
1
20
25
8
103
100
0.23
2
455
290
95
120
50
4
515
130
115
250
250
0.25
Total Quantity
990
445
218
473
400
0.48
Unit Price
$ 2.40
12.00
12.00
24.00
8.40*
2,000.00
Amount
$ 2,376.00
5,340.00
2,616.00
11,352.00
3,360.00
960.00
Total
$ 26,004.00
The unit price of $8.40 per cubic yard for rehandling and washing
silted crushed limestone that remained in the barriers after the floods
was a negotiated price not included in the original contract, and
represented 35 percent of the contract bid price for furnishing and
installing new materials.
NOTE: To convert cubic yards (cu. yds.) to cubic meters, multiply
cu. yds. x 0.7646
To convert square yards (sq. yds.) to square meters, multiply
sq. yds. x 0.8361
To convert acre to hectare, multiply acre x 0.4047
45
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SECTION VII
STREAM SAMPLING AND LIMESTONE ANALYSIS
GENERAL
Stream gaging and water sampling in connection with the evaluation of
the performance of the Trough Creek Limestone Barriers was conducted on
a monthly basis. This work was started prior to placement of any crushed
limestone materials in the stream, and continued through the construc-
tion phase and for an additional period of time of approximately 17
months after completion of construction and flood damage repairs. Se-
lected samples of limestone were placed in stainless steel containers
in the harriers during construction, and were periodically removed,
weighed and replaced. Electron tnicroprobe and X-ray diffraction inves-
tigations were made on limestone samples to determine the chemical com-
position of deposits formed on the stones, and a determination was made
of various algae and protozoan species mixed with the inorganic coating
materials on the stones.
Eight (8) stream gaging stations were provided for measuring stream-
flow through the individual barriers, and fifteen (15) water sampling
points were established. Figures 18 through 23 show the stream gaging
stations and water sampling points at the various limestone barrier
sites.
Stream Gaging
Streamflow was measured in gaging flumes of constant cross-section by
the velocity-area method. Velocity was measured by a Gurley "Pigmy"
current meter, except that a timed surface float was used under certain
conditions when streamflow and depth of water was so low that meter
readings appeared erratic.
During the construction phase of the Project, water samples were col-
lected monthly at each of the six (6) limestone barrier sites. At the
sites where gaging flumes were in place, streamflow was measured as noted
above. However, at proposed downstream sites where gaging flumes had
not been constructed, water samples were collected and streamflow was
noted either "Estimated" or "Not Recorded." "Estimated" streamflow de-
terminations were made either by surface float or current meter, where
all streamflow appeared to be confined to stream sections where the vel-
ocity could be measured and the cross-sectional area reasonably deter-
mined. Where the pattern of streamflow was such that a reasonable esti-
mate of flow could not be determined, it was noted "Not Recorded."
46
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_-
-~-
GENERAL LOCATION PLAN
LIMESTONE SAgglER.5 -SITE N-i
I SAMPLING POtNT
Figure 18. Sampling Points and Gaging Station —Site No. I
-------
y-
GENERAL LOCATION PLAN „.
LIMESTONE BARRIERS - SITE A/g 2
•to go
Figure 19. Sampling Points and Gaging Station —Site No. 2
-------
LIME.STOUB SABGIEP M* 3C
LIMESTONE. BOKKIEK N* 3 A
SAMPLING PO/AIT
A/s 3A-D
SAMPLING POINT
/V* 38-0
GENEZAL LOCATION PLAN
LIMESTONE BARRIERS -SITE A/fi 3
PO/MT \ \ \
SCALE
Figure 20. Sampling Points and Gaging Station —Site No. 3
-------
SAMPLING. POINT
GAGING
FLUME
SAMPLING
POINT N*4-U
X
^L/M£5TONE B»KGl€K MS 4 C
GENEPAL LOCATION PLAN
LIMESTONE BARRIERS -SITE A
Figure 21. Sampling Points and Gaging Station—Site No. 4
-------
V M
13 4 a>
M « C
-PZ.XW-
LIMESTONE BARRIERS N^ 5A 453
10 It 0
Figure 22. Sampling Points and Gaging Station — Site No. 5
-------
~-
SAMPLING PO/N T
A/2 6-D
'—SAMPLING POINT
AJt 6-U
GENERAL LOCATION PLAN
LIMESTONE BARRIE8S -SITE N° G
Figure 23. Sampling Points and Gaging Station—Site No. 6
-------
Water Sampling
At each site, water samples were collected upstream and downstream from
the individual barriers. The collected water samples were packaged and
sent to testing laboratories designated by the Commonwealth of Pennsyl-
vania. The water sample analysis consisted of determinations of pH,
acidity, alkalinity, sulfates and iron. The testing laboratories were
under contract with the Commonwealth for performing such services, and
throughout the course of this sampling program, four separate laborator-
ies conducted the chemical analyses.
During the construction phase of the Project, only one monthly sample
was collected in the main stream and tributary at uncompleted limestone
barrier sites. As previously mentioned, restoration work was undertaken
at Limestone Barrier Site Nos. 1, 2 and 4 to repair 1972 flood damages.
Although the barriers at Site Nos. 3 and 6 were not included in the
authorized restoration work, water samples were collected and analyzed
at these sites for the full sampling program period. When it became
obvious that barrier performance at Site No. 5 was no longer effective
because iron sludges had coated rock surfaces and clogged voids in the
crushed limestone materials, water sampling at this site was discontin-
ued.
A complete tabulation of the results of analysis of water samples col-
lected during the study period is presented in the Appendix. Figures
.24 through 29 show a plotting of pH values at the various sites, up-
stream and downstream from the barriers. These figures also show the
rate of stream flow at the time of sample collection, and the sequence
of construction of the limestone barriers.
As previously noted, iron concentrations were generally less than 1
milligram per liter at all sampling points, except at Site No. 5. The
results of the sampling program are discussed in SECTION VII.
Limestone Analysis
The limestone analysis phase of the sampling program to evaluate the
effectiveness of the Trough Creek Limestone Barriers consisted of placing
selected samples of limestone in the barriers in 22.86 cm x 22.86 cm x
22.86 cm (9" x 9" x 9") stainless steel baskets. The baskets were of
welded construction and were fabricated from 2,54 cm x 2.54 cm x 0.32 cm
(1" x 1" x 1/8") angle frames and 0.305 cm (0.120") wire screens. Wires
for screens were spaced 2.54 cm (1") center to center both ways. Twelve
baskets (two at each limestone barrier site) were installed in the bar-
riers in 1971 and 1972 following completion of the work under the origi-
nal construction project. Initially it was intended that the baskets be
removed from the barriers at each site at three month intervals and be
53
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analyzed for:
(a) Loss of weight as a factor of time and flow
(b) Tendency for deposits to form on the limestone
(c) Chemical composition of any deposits
In this connection, vandalism was a problem at Site Nos. 1 and 2, and
some of the baskets at other sites were washed away or damaged during
the March and June 1972 floods. Of the original twelve baskets that
were installed in the barriers only four baskets were recovered which,
upon loss of weight analysis, appeared to provide reasonably accurate
data. These baskets were subsequently placed in the barriers at Site
Nos. 1, 2 and 4 following completion of flood restoration work in late
1972.
The schedule for removal and replacement of limestone filled baskets at
three month intervals could not be strictly adhered to, because it was
not possible or practical under certain conditions due to the nature of
streamflow in Trough Creek. The baskets had to be placed near the
bottom of the barriers to insure that they would be submerged during
periods of low stream flow. Installation of the baskets during average
or high streamflow would have required the use of heavy construction
equipment, which could have damaged the baskets and abraded the stones
during installation and/or removal, thus increasing the probability of
error in the loss of weight analysis.
Usually when baskets were removed from the barriers for sampling, silt
deposits, ranging from light to severe, were present in the voids of
the limestone pieces. The limestone samples in each basket were washed
with clean water, scrubbed lightly with a soft fiber brush, dried,
weighed and then returned to the barriers. Tables 10 through 13 show
loss of weight of the limestone samples in the four baskets that were
preserved and protected during the study period.-
A review of the limestone analysis indicates that the rate of loss-of-
weight (percent per year) fluctuated over a wide range. This variation
is attributed to the fact that sediment deposits clogged interstices
between the stones, thus inhibiting free stream flow through the baskets
and lessening the opportunity for reaction of the limestone with flowing
acidic water. This matter is discussed in detail in SECTION VIII. Al-
though the average rate of limestone consumption appeared to be in the
neighborhood of 3 to 5 percent per year, it would be ill-advised to
attempt to predict the life of the limestone barriers on the basis of
the results of this loss-of-weight analysis.
54
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Table 10. LIMESTONE ANALYSIS - BASKET NO. 2
Date Inatalled (I)
Date Removed (R)
2/10/71
2/3/7?
2/8/72
l/2li/73
2/8/73
8/10/73
8/21/73
12A3/73
1/3/7U
S/10/7U
5/23/7U
8/2/7U
Table 11.
(I)
(R)
(I)
(R)
(I)
(R)
CD
(R)
(I)
(R)
(I)
(R)
Weight Loaa of Weight Time
(Ke) (Kg) (Sara)
12.1714
0.1,714 3S8
12.0
12.0
0.013 351
11.987
11.987
0.212 183
11.775
11.775
0.123 111
11.652
11.652
0.193 126
11.1*59
11.U59
0.100 70
11.359
Rate of Loaa Conulatlra Loaa
of Weight of Weight
Wjwr yew) (Ka)
3.87U O.lrfli
0.112 0.1.87
3.528 0.699
3.U36 0.822
U.797 1.015
li.552 1.US
Total EUpeed
Time
(Oaya)
358
709
892
1,003.
1,129
1,199
LIMESTONE ANALYSIS - BASKET NO. 6
Date Inatalled (I)
2/8/72
5A8/72
6/20/73
12/13/73
1/3/7U
S/10/7U
5/23/714
8/2/7U
(I)
(R)
(I)
(R)
(I)
(R)
(I)
(R)
Weight Loaa of Weight Time
flC^ IK,) tDM)
12.5
0.122 100
12.378
12-37fl 0.279
12.099
"•°" 0.098 126
12.001
0.165 70
11.836
Rate of Loss Cumulative Loaa
of Weight of Weight
« per year) (KB)
3.562 0.122
U.67U O.ljOl
2.3U6 O.U99
7.170 0.66ti
Total Elapsed
Tine
(Days)
100
276
U02
1*72
55
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Table 12. LIMESTONE ANALYSIS - BASKET NO. 8
Date Installed (I)
Date Honored (H)
2/8/72
5A8/72
1/2U/73
12/13/73
1/3M
5AO/7U
5/23/7U
8/2/fl
Table 13.
(I)
(R)
(I)
(R)
(I)
(R)
(I)
(R)
Hate of toss
Weight loss of Weight Tine of Weight
(Kc) UK) (Days) « per year)
12.9
0.02$ 100 0.708
12.875
12.875
0.325 323 2.852
12.555
12.555
0.173 126 3.992
12.382
12.382
0.273 70 11.1*98
12.109
emulative Loss
of Weight
(X*)
0.025
0.350
0.523
0.796
Total Elapeed
Time
(Days)
100
b23
5I«9
619
LIMESTONE ANALYSIS - BASKET NO. 9
Date Installed (I)
2/6/72
l/2li/73
2/8/73
8/10/73
8/21/73
12A3/73
1/3/7U
5AO/7U
S/23/7U
8/2/7U
(I)
(R)
(I)
(R)
(I)
(R)
<«
(R)
-------
Limestone Coatings
After the barriers were in service for some time, the coatings on sur-
faces of the crushed limestone materials were examined for chemical
composition and biological growth. The Pennsylvania Fish Commission
collected stone samples in July 1971 at Site Nos. 1, 2 and 3. They
found that the material coating the limestone at each site contained
a significant amount of inorganic materials. Attached to and mixed
with this material were various forms of algae and protozoan species.
At the time of the Fish Commission sampling the barriers at Site No. 1
had been in service for approximately 9 months, at Site No. 2 for approx-
imately 6 months, and at Site No. 3 for approximately 3 months. The
results of the biological survey were as follows:
Site No. 1 - Diatoms and protozoans abundant in the film coating
the limestone.
Site No. 2 - Diatoms replaced by filamentous algae which were
abundant. Protozoans were reduced in number and
diversity.
Site No. 3 - Film consisted primarily of inorganic materials,
with very few protozoans or algae forms present.
Deposits on limestone samples collected from the barriers were also
examined and anlyzed by X-ray diffraction, and later by electron micro-
probe to determine elements present in the coating materials. In July
1972 the coatings from limestone samples collected from each limestone
barrier site (six total) were scraped off and subjected to X-ray diffrac-
tion analysis. All samples showed poor crystallinity, making phase iden-
tification difficult.. The materials that were;identified were calcite
(from the limestone), quartz and gypsum. Visually it could be seen
that iron oxides were present in the rock coatings, but since the X-ray
patterns did not show the presence of any iron compounds, they were as-*
sumed to be amorphous (amorphous or non-crystalline materials will not
give an X-ray diffraction pattern, hence cannot be identified by this
technique).
In November 1972 an electron microprobe investigation was made of the
deposits on limestone samples collected from the barriers at Site. Nos.
2, 3 and 5. Two wavelength scans were made of the deposits on these
samples, and the analysis showed the following elements present:
Site No. 2 - Silicon, Potassium, Aluminum, Iron
Site No. 3 - Aluminum, Silicon, Titanium, Potassium, Calcium,
Iron
Site No, 5 - Calcium, Aluminum, Iron, Silicon, Potassium, Sulfur
One wavelength scan was made of a limestone sample collected from the
57
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barrier at Site No. 1. The coating deposits on the surface of this
stone were removed prior to analysis, and the investigation of this
sample did not show any elements being absorbed.
58
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STREAMFLOW cfi
19 IS 17 16 15 14 13 12
BARRIERS AT THIS SITE
RECONOITIONEO 10/10/72
FLOOD-JUNE, 1972
pH UPSTREAM
pH DOWNSTREAM
FLOW
LIMESTONE BARRIERS SITE I
KV26/7D
Figure 24. Performance of Limestone Barriers—Site No.
59
-------
30
STREAMFLOW (cfi)
20 15
BARRIERS AT THIS SITE
RECONDITIONED 12/5/TZ
FLOOD-JUNE, 1972
—•—•— pH UPSTREAM
pH DOWNSTREAM
— FLOW
LIMESTONE »ARRIERS AT SITE Z
CONSTRUCTED I/2Z/7I
LIMESTONE JARRIERS AT SITE I
CONSTRUCTED IO/26/7O
•-
Figure 25. Performance of Limestone Barriers —Site No. 2
60
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STREAMFLOW (cfs)
25 ZO
__ _ — PH UPSTREAM
pH DOWNSTREAM
FLOW
IMESTONE BARRIERS AT SITE 3
CONSTRUCTED 4/Z9/7I
FLOW NOT WCORDED
I
LIMESTONE BARRIERS AT SITE !
CONSTRUCTED 1/22/71
LIMESTONE CARRIERS AT SITE. I
CONSTRUCTED 10/26/70
Figure 26. Performance of Limestone Barriers —Site No. 3
61
-------
90
80
70
STREAMFLOW (da)
60 50 40
30
20
10
LIMESTONE BARRIERS AT SITE 4
CONSTRUCTED 8/2O/7I
JAN.
— — — pH UPSTREAM
——— pH DOWNSTREAM
FLOW
LIMESTONE BARRIERS AT SITE 3
CONSTRUCTED 4/29/71
LIMESTONE BARRIERS AT
CONSTRUCTED 1/jJ/Tl
LIMESTONE BftRBIEBS AT SITE I
CONSTRUCTED IC/26/70
JAN
z o
o~
Figure 27. Performance of Limestone Barriers—Site No. 4
62
-------
STREAMFLOW (cfs)
2
pH UPSTREAM
' pH DOWNSTREAM
FLOW
FLOOD- JUNE, 1972
JAN.
Q
-•
N
!„
1
.1
:-
JAN.
LIMESTONE BARRIERS AT SITE 5
CONSTRUCTED 5/2O/7I
\
^> -
t -
i
JAN.
Figure 28. Performance of Limestone Barriers—Site No. 5
63
-------
90
60
70
STREAMFLOW (cfs)
60 50
40
30
20
10
LIMESTONE BARRIERS AT SITE 6
CONSTRUCTED 11/26/71
LIMESTONE BARRIERS AT SITE 4
CONSTRUCTED 8/20/71
JAN.
Q
•
VI
•I
LIMESTONE BARRIERS AT SITE 3
CONSTRUCTED 4/29/71
pH UPSTREAM
pH DOWNSTREAM
FLOW
LIMESTONE BARRIERS AT SITE 2
CONSTRUCTED 1/22/71
LIMESTONE BARRIERS AT SITE I
CONSTRUCTED O/26/7O
JAN.
I.H
Figure 29. Performance of Limestone Barriers—Site No. 6
64
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SECTION VIII
LIMESTONE BARRIER PERFORMANCE
GENERAL
The performance of six Trough Creek prototype limestone barrier instal-
lations was observed during and after the construction phase of the pro-
ject for the period extending from October 1970, when the first barrier
was erected, to August 1974. Information gathered throughout the samp-
ling program period, together with observations noted in the field, made
it possible to evaluate the effectiveness of in situ limestone barriers
over a wide range of stream conditions. The field observations and t"he
data collected during the sampling program also provided useful infor-
mation in evaluating the extent to which design relationships used for
this project, that were developed from laboratory research, could be
supported.
It is apparent from even a cursory examination of the results of the
stream sampling program that the limestone barriers, as constructed,
were not successful in providing workable facilities satisfactory for
area-wide abatement of pollution from acid mine drainage in the upper
reaches of the Trough Creek Watershed. Although barrier performance
was excellent during periods of low stream flow, in terms of reducing
acidity and raising the pH of the water, their effectiveness was mar-
ginal at design flows, and they were completely ineffective when high
runoffs were experienced. Also, it is apparent from a review of the
results of the stream sampling program that limestone barriers are
most efficient when they are initially installed, or after they have been
otherwise restored by reconditioning and repair work similar to that un-
dertaken following the 1972 flood. For the Trough Creek Project, lime-
stone barrier performance deteriorated after the the structures had been
in service for some time following initial construction, and again after
the barriers had been reconditioned following flood damage restoration
work.
Deterioration of Limestone Barrier Performance
The rate of deterioration of limestone barrier performance is apparently
dependent upon two major factors; namely, siltation and coating of the
surfaces of the stones. The most serious cause of barrier deterioration
for the Trough Creek Project appeared to be sealing of the crushed lime-
stone materials, whereby sediment accumulations of either silt or iron
sludges clogged interstices between the stones. The result of such clog-
ging not only reduces the effective porosity and hydraulic conductivity
of the crushed limestone beds, but also lessens availability of the
reagent (limestone) to flowing acidic water.
65
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When limestone barriers are initially constructed, or after they have
been reconditioned, almost all of the limestone materials are available
for neutralization. However, after sediment deposits begin to accumu-
late and clog voids in the limestone materials, the streamflow pattern
through a barrier begins to channel, causing short-circuiting of the
flow and the resultant reduction in retention time. The hydraulic
capacity of limestone barriers likewise diminishes as silt deposits
accumulate, because the permeability of clogged or partially clogged
beds becomes substantially reduced.
The other factor that causes deterioration of the performance of
limestone barriers is coating of the surfaces of the stones with silt
or iron hydroxides. During periods of turbid or muddy streamflow, silt
collects on the surfaces of the stones. The effect of coating of the
stones is a buffering action that effects a reduction in the neutrali-
zing ability of the limestone. Although the silt coatings are easily
removed physically by washing, they do not have a tendency to wash or
flake off in the stream. Rather, they tend to build up over a period
of time, depending on stream conditions, and progressively lessen lime-
stone reactivity. It was also found that during the warmer months of
the year algae growths were mixed with the inorganic coating materials.
For the Trough Creek Project, the combined effect of coating of the sur-
faces of the stones and sealing of the beds was that deterioration of the
performance of the limestone barriers was experienced within a few months
after initial construction, and again after reconditioning. It should be
noted, however, that except where the surfaces of the stones become ar-
mored with iron hydroxides, the upper layer of limestone appears to
remain effective, because the barriers continued to neutralize acidity
when stream flow was very low.
General Observations - Silting of Limestone Barriers
Where limestone barriers are to be installed to neutralize acidity in
streams subject to severe flooding and a wide variation of flow, acknow-
ledgment must be made of the fact that sediment deposits will tend to clog
voids in the crushed limestone materials and stone surfaces will become
coated with silt. In this connection, the following observations were
noted for the Trough Creek Project:
1. Silting, and the resultant clogging of voids of limestone
materials, is more pronounced during the first year after
installation, because: (a) existing stream beds and streamflow
patterns were altered, and (b) vegetation and natural ground
cover adjacent to the structures was disturbed and/or des-
troyed during the construction operations, thus increasing
the possibility of soil erosion from surrounding areas.
66
-------
2. Where limestone barriers are constructed in areas where the
slope of the stream bed is steep, such as at Site No. 3, con-
sideration should be given to lining both the creek banks and
channel with rocks for the entire reach of stream to prevent
erosion, and also the placement of large stones in the channel
area approaches to disrupt and disperse streamflow patterns.
3. Stream channel approaches to the limestone barrier sites should
include provisions for dissipating the kinetic energy of stream
flow. The work under the Trough Creek Project included con-
struction of grouted stone rip-rap flumes at each site for the
purpose of measuring the rate of stream flow during the samp-
ling program. At Site Nos. 3, 4 and 6 the flumes were installed
upstream from the barriers and provided a straight, fairly
smooth channeled water course of constant cross-section with
invert elevations higher than what was expected to be normal
water level. During periods of high runoffs the streamflow
through the flumes approaches scouring velocity, and apparently
stirs and churns previously settled mud and silt in the stilling
basin areas, carrying these materials onto the barriers.
Concurrent Studies - Trough Creek Limestone Barriers
In November 1972, the Institute For Research On Land And Water Resources
at The Pennsylvania State University initiated additional research rela-
tive to the reactivity of limestone with acid mine waters. (3)This
research work was undertaken after the limestone barriers at Site No. 1,
2 and A had been substantially restored to approximate original condition
following damages experienced as a result of the June 1972 flood. The
water sampling and analysis portion of the University study was conducted
concurrently with the sampling program under this evaluation project;
however, the chemical analysis and the laboratory testing procedures at
the University were considerably more comprehensive in scope.
The University Study concluded basically that limestone barriers can be
used effectively to neutralize acid waters if they are designed properly
and if the iron concentrations are sufficiently low. The study indicated
that the proper design was found to depend very heavily on the reduction
of reactivity of the limestone due to deposits of silt and precipitates
which may have formed. For the barriers in Trough Creek this reactivity
was found to have apparently decreased five-fold from limestone reacti-
vity monitored under clean conditions in the University laboratory.
As a consequence of this University study, a set of design graphs was
generated which incorporate the reduction in limestone reactivity so
that the designer can take this factor into account and build the system
sufficiently large to overcome this deficiency. The University concluded
67
-------
that even with the increased volume requirement, limestone barriers
appear to provide a reasonably economical solution for neutralization
of acid waters under conditions of low iron concentrations,
Evaluation - Limestone Barriers
The undertaking of construction of the Trough Creek Limestone Barrier
Installation Project was the first such endeavor for in-stream treat-
ment of acid mine drainage for an entire watershed where the range of
streamflow was of the magnitude of Trough Creek. The design relation-
ships used for this prototype project were developed from laboratory
research in the late 1960's at The Pennsylvania State University,
Presented below are evaluations of the design relationships based on
the experiences of the performance of the Trough Creek Limestone Bar-
riers. These evaluations are based on results of the sampling program
and field observations noted during the study period October 1970 to
August 1974.
1. The performance of the limestone barriers, in terms of redu-
cing acidity and raising the pH of the water, did not reach
theoretical efficiency, except for a short period of time at
Site No. 5. A possible explanation for the reason they did
not reach theoretical efficiency is that the design relation-
ships for reduction of acidity were formulated from labora-
tory experiements using synthetic acid waters of both 50 and
100 mg/1 initial acidity; whereas, initial stream acidities
(upstream from the barriers) for the Trough Creek Project
were only in the neighborhood of 10 to 20 mg/1, except at
Site No. 5 where initial acidity was approximately 150 to
200 mg/1. If initial acidity in the stream had been some-
what higher, the percent reduction of acidity may have been
greater.
2. Limestone barrier performance was more efficient for the long,
continuous barriers at Site Nos. 1, 4 and 5 than it was for
the short, multiple barriers at Site Nos. 2 and 3. The lab-
oratory research thesis postulated that' acidity reduction is
proportional to the total length of the barrier, without regard
to whether it is an integrated long structure or comprised of
segregated short units. At Site Nos. 2 and 3 two short bar-
riers, approximately 7.6 meters (25 feet) in length, were
positioned in series in the.main channel of the stream. At
Site Nos. 1 and 4 the barriers were interconnected with shallow
limestone fills and the barrier at Site No. 5 consisted of a
single structure. The limestone fill areas for the barriers
at Site Nos. 1, 4 and 5 were all in excess of 45.7 meters (150
feet) in length.
68
-------
3. The performance of the limestone barrier at Site No. 5 was
excellent after completion of initial construction. The
characteristics of the raw acid mine drainage at this Site
were approximately 150 to 200 mg/1 acidity and 30 mg/1 (total)
iron. Within a period of approximately three months the per-
formance of this barrier, for all practical purposes, com-
pletely deteriorated because of accumulations of iron sludges
in the limestone bed and armoring of the surfaces of the stones
with iron hydroxides.
4. Initial performance of the limestone barriers was good at all
other sites (Nos. 1, 2, 3, 4 and 6), where iron concentrations
of the water were approximately 1 mg/1 or less, but perform-
ance also deteriorated to a considerable degree after a few
months following completion of construction. This deterior-
ation is attributed to sediment accumulations sealing the lime-
stone beds and also coating of the surfaces of the stones with
silt. This condition was discussed in detail previously in.
this SECTION.
5. The performance of silted limestone barriers can be restored
to approximate initial efficiency by performing recondition-
ing work similar to the procedures adopted for flood damage
repairs at Site Nos. 1, 2 and 4.
6. It was difficult to attempt to assess the accuracy of hydraulic
design relationships regarding head losses, stone size and flow
through the barriers, because sediment deposits accumulated in
a short period of time following completion of construction,
causing "dead spots" in the barriers and channelling flow
through indeterminate areas. However, the head loss relation-
ships seemed to be confirmed by observations noted over a limi-
ted range of streamflow during the short period of time the
barriers were in clean condition.
7. Although the research thesis recommended the use of small stone
sizes for the crushed limestone materials, consideration must
be given to the magnitude of high runoffs and flood flows that
might occur that will cause scouring of the materials. For the
Trough Creek Project a considerable degree of scouring was
experienced, even though the larger stone sizes (6.35 cm to 10.16
cm, or 2 1/2" to 4") were used in the barriers.
69
-------
Comments Regarding Future Limestone Barrier Design
On the basis of the conditions experienced with the Trough Creek lime-
stone barriers, it is apparent that the design of such units must take
into account the effect of deteriorating barrier performance caused by
siltation and coating of the surfaces of the stones. The five-fold re-
duction in limestone reactivity noted in the recent Pennsylvania State
University research study would appear to provide an ample factor of
safety for design. Likewise, it seems apparent that in the design of
limestone barriers, the size of the units should be determined from
design flows greater than those used for this project. (Design flows
for Trough Creek Limestone Barriers were 1.25 times computed average
flow.) A considerable portion of the Trough Creek Project watershed
consists of wooded lands, some farms, and other areas where acid mine
drainage would not be generated from surface runoffs. Originally, it
was believed that ample dilution of stream acidity would be afforded
during periods of high surface runoff from these areas. The results
of the sampling program indicate that a more realistic value for design
flow would appear to be approximately 300 percent of computed average
streamflow, depending on watershed conditions.
Barrier configuration will naturally depend to a certain degree on top-
ography of the areas adjacent to proposed structures. However, barrier
performance will probably be more efficient if the units are long, con-
tinuous structures, flat and relatively shallow (approximately 1 meter
or 3 feet in depth or less), and constructed in areas where adequate
hydraulic gradient is available under all conditions of streamflow.
It is evident that a maintenance program should be established to period-
ically recondition limestone barriers so that performance will not de-
teriorate beyond required efficiencies. The scheduling and extent of
such maintenance work would be dependent on local conditions and water-
shed runoff characteristics.
A reasonable estimate of the life of properly operated limestone barriers
could not be determined from the limestone loss of weight analysis, be-
cause of the siltation problems noted in SECTION VII. However, with the
excess volume of limestone needed to compensate for reduction in lime-
stone reactivity, together with the larger structures required to accomo-
date high design flows, the amount of crushed limestone materials that
would be furnished for properly sized units would undoubtedly provide
ample reagent for many years.
In view of the deficiencies in performance of the limestone barriers on
the Trough Creek Project, it is questionable whether it is feasible to
attempt to provide in-stream limestone barriers exclusively as the
treatment method for area-wide mine drainage pollution abatement, even
70
-------
though the chemical characteristics of the acid waters appear suitable
to treatment with limestone. Rather, it is believed that construction
of limestone barriers in conjunction with other watershed improvements,
such as backfilling strip mined areas, replanting and possibly some
mine sealing, would be a more practical approach to regional mine
drainage pollution abatement where the watershed areas and runoff
characteristics are similar to those of Trough Creek.
71
-------
SECTION IX
REFERENCES
1. Yen, Alan Fong - I, Design of Limestone Barriers in Acid Mine
Water Streams, A Thesis in Civil Engineering, The Pennsylvania
State University, University Park, September, 1969.
2. Africa Engineering Associates, Inc., details reproduced from
Plans for Contract No. SL-121-1, Construction of Limestone
Barriers - Trough Creek Watershed - Huntingdon and Bedford
Counties, Pa., prepared for Department of Mines and Mineral
Industries, Commonwealth of Pennsylvania, by Africa Engineering
Associates, Inc., Consulting Engineers, Huntingdon, Pa., 1970.
3. Pearson, F. H. and McDonnell, A. J., "Neutralization of Acidic
Wastes by Crushed Limestone, "Research Publication No. 79, and
"Evaluation of Prototype Crushed Limestone Barriers for the
Neutralization of Acidic Streams," Research Publication Number
80, Institute for Research on Land and Water Resources, The
Pennsylvania State University, University Park, Pennsylvania,
June, 1974.
72
-------
SECTION X
APPENDIX
Page
A. Key to Symbols Used in Reporting Results
of Water Analysis and Sample Collections 74
B. Water Analysis - Site No. 1 75
C. Water Analysis - Site No. 2 78
D. Water Analysis - Site No. 3 80
E. Water Analysis - Site No. 4 84
F. Water Analysis - Site No. 5 88
G. Water Analysis - Site No. 6 90
73
-------
COMMONWEALTH OF PENNSYLVANIA
DEPARTMENT OF ENVIRONMENTAL RESOURCES
BUREAU OF PLANNING AND COAL RESEARCH
TROUGH CREEK LIMESTONE BARRIER INSTALLATION AND EVALUATION
PROJECT NO. 14010 - FWW
CR-105
KEY TO SYMBOLS USED IN REPORTING RESULTS OF WATER ANALYSIS AND SAMPLE
COLLECTIONS
* Estimated stream flow. Accurate measurements of Stream Flow were not made until
grouted rip-rap measuring flumes were constructed.
N.R. Stream Flow not Recorded. Flow pattern of stream was such that a reasonable
estimate of the rate of flow could not be made at time of sample collection.
Values not reported by Testing Laboratory.
IQUENCE OF
Site No.
\
2
3
4
5
6
CONSTRUCTION - LIMESTONE BARRIERS
Date Started
July 27, 1970
October 27, 1970
January 25, 1971
May 20, 1971
May 3, 1971
August 20, 1971
Date Completed
October 26, 1970
January 22, 1971
April 29, 1971
August 20, 1971
May 20, 1971
November 26, 1971
(Extra Work)
Change Order No. 1
1,4,5,6 April, 1972 May 15,1972
(Extra Work)
Change Order No. 2
1,2,4 September 26,1972 December 5,1972
NOTE: To convert cubic feet per second (cfs) to m3/s; multiply cfs x 0.02832
74
-------
TROUGH GREEK LIMESTONE BARRIER INSTALLATION AMP EYALUATIOK
SHEET I WATER ANALYSIS
Sampling
Date
10/2/70
10/28/70
11/27 /YO
12/30/YO
1/26/71
2/26/71
3/30/71
U/28/71
5/28/71
7/2/71
3/5/71
8/31/71
10A/71
iiA/n
12/1/71
l/h/72
2A/72
2/28/72
Flow
(cfs)
0.25*
0.8U
8. It
10.2
7.0
12.0
5.0
0.8U
U.2
0.13
0.78
0.00
0.26
2.6
•5.26
3.9
2.2
U.9
- SITE NO. 1
PH
1-TJ
3.8
3.8
U.U
U.3
U.3
U.6
U.6
U.3
U.I
U.6
3.7
Samples
3.7
3.9
U.O
U.2
3.9
U.I
1-D
6.0
5-2
U.6
U.8
U.8
U.8
5.5
U.7
7.2
5.6
Acidity Alkaltolty
"(rogA) (mgAl
1-TJ
32
32
6
8
8
0
10
12
0.6
—
22
not collected - no
6.1
U.8
a. 8
5.2
U.U
U.I
22
6
U
u
8
U
l-D 1-U
0
U
0 0
10
u o
0 0
12 —
8
__
U
0
flow
—
0
0
—
6
2
1-D
8
0
0
0
U
—
0
6
uu
0
8
0
0
6
~
SOU (me/3
(mgA!
1-U ]
105
70
—
2lt
PROJECT NO
. 1U010 - FWW
CR-105
L) Iron (wRA)
1-U
L-D Total
0.55
6.25
0.25
28 1.7
1-D
Ferrous
32 100 3.3
32
28
36
UO
20 0.35
28 0.1
28 0.55
28 0.1
UU 80 0.1
75 75 6.0
95 75 0.3
UO 30 0.1
2U 18 0.1
UU UO 0.1
38
UO 0.1
Itlt UO 0.1
0
0
0
0
0
0
0
0
0
0
0
0
Total
O.Y
1.65
5.25
0.35
0.7
0.1
0.35
0.1
1.1
U.2
0.1
0.1
0.1
0.1
0.1
0.1
Ferrous
0
0
0
0
0
0
0
0
0
0
0
0
-------
TROUGH CHEEK LIMESTONE BARRIER INSTALLATION AND EVALUATION
(Con't)
Sampling
Date
3/31/72
U/25/72
5A8/72
7/5/72
7/2h/72
8/22/72
9/26/72
10/26/72
11/30/72
1/8/73
2/15/73
3/30/73
U/23/73
5AO/73
6/7/73
7A6/73
8A7/73
10A6/73
10/2U/73
SHEET II
Flow
(cfs)
N.R.
7.0
6.6
7. *
O.U
0.05*
c.oo
0.00
8.7
7.0
12.0
7.0
12.0
U.8
2U.7
0.3
trickle
trickle
O.U
WATER ANALYSIS - SITE
pH
1-U
U.6
U.7
U.2
U.7
U.9
5.1
Samples
n
U.3
5.o
U.5
5.5
U.6
U.5
U.6
U.8
6.7
6.1
3.9
NO. 1
Acidity
(BRA)
1-D
U.7
U.8
U.8
U.9
7.2
7.0
not
n
7.1
5.5
5.9
5.1
U.7
U.7
U.8
7.0
7.2
7.0
6.6
1-U
9
8
8
12
1U
16
collected -
ti
n
3
7
. 3
9
8
10
8
0
0
18
1-D
25
7
n
10
8
15
no flow
,,
9
7
6
5
6
10
5
0
0
0
10
PROJECT NO. 1U010 - FWW
Alkalinity
1-U
2
2
~
—
—
2
0
9
0
0
0
0
0
0
0
0
0
1-D
3
2
—
—
—
U5
18
12
0
0
0
0
0
20
52
Uo
10
SOU (mgA)
1-U
20
2U
21
29
2U
31
27.5
22.5
2U
20
22
26
22
29
2U
26
Uo
1-D
25
26
25
30
26
37
29
25
17
20
2U
26
2U
2U
26
36
60
CR-105
Iron (m
1-U
Total Ferrous
0.21 0.12
0.32 0.08
0.33 0.06
O.U7 0.06
0.33 0.06
0.52
0.20 0.02
0.21 O.C8
0.2 <0.2
0.1
<0.1
0.2 <0.2
<0.1
-------
TROUGH CREEK LIMESTONE BARRIER INSTALLATION AND EVALUATION
(Can't) SHEET HI WATER
Sampling How
Date (cfs)
11/23/73
12A9/73
2AU/7U
3A/7U
UA1/7U
U/30/7U
5/28/7U
6/27/7U
8/5/74
3.7
8.6
6.9
12.0
7.1
7.1
8.1
6.7
Trickle
ANA1TSIS - SITE NO, 1
Tfl
1-0
3.8
U.2
u.u
U.o
U.2
U.3
lt.5
U.l
5.6
1-D
U.I
U.3
u.u
U.3
U.2
U.3
U.6
U.1
6.5
Acidity
(npA)
1-U
8
U
6
U
6
6
2
10
8
1-D
10
2
6
8
6
6
2
10
6
Alkalinity
CragA)
1-U
0
0
0
0
0
0
0
0
12
1-D
0
0
0
0
0
0
0
0
82
PROJECT NO. 1U010 - JWW
SOj, (mgA)
1-U
35
23
20
26
U5
23
27
26
26
1-D
33
22
21
27
35
26
26
2U
30
CH-105
Iron (n
1-0
Total Ferrous
0.1U6
0.1U6
0.1U6
0
0
o —
0
o —
o —
eA)
1-D
Total
0.1U6
0.1U6
0
0
0
0
0
0
0
Ferrous
. —
_ __
- —
_ __
-------
TftOUQH CREEK LDESTCTTE 3ARRIEt TH3TAU.ATIM AHD EVAMHTIOK
oo
SHEET I
Date
10/2/TO
10/28/70
11/27/70
12/30/70
1/26/71
2/26/71
3/30/71
U/28/71
S/28A1
7/2/71
s/sm
8/31/71
10A/71
11/1/71
12/1/n
l/U/72
2A/72
2/28/72
3/31/72
U/25/72
SAB/72
7/5/72
7/2U/72
8/22/72
WATER ANALYSIS
Plow
(cfs)
0.65*
2.0
9.6
U.6
8.U
20.0
1U.8
2.1
S.o
0.6
1.35
0.01
0.61
8.5
S.o
6
6.5
6.8
8.1
20.3
1U.O
19.3
0.7
0.06
2-U
U.6
U.7
U.9
U.6
U.7
S.O
U.8
U.7
U.U
U.2
s.s
U.o
U.7
U.3
5.3
5.0
U.2
U.U
i.8
6.1
U.8
5.U
5.2
U.8
PH
2B-D
U.6
S.O
S.O
U.6
U.7
5.U
6.3
U.8
U.7
5.2
5.1
U.I
U.8
k.6
3.9
U.9
S.U
5.8
6.1
- SITE KO. 2
Acidity (n*.A)
2A-D
5.7
S.o
5.0
5.1
U.9
6.0
5.6
6.U
5.2
U.7
5.2
U.8
U.3
U.8
U.9
3.7
U.9
5.3
7.2
6.9
2-D
16
3
10
10
0
U
8
2
U
8
0
12
0
6
0
—
U
2
7
6
5
5
22
20
2B-D
0
U
8
— ..
0
0
~
10
u
2
—
6
—
8
10
6
6
9
27
2A-D
2
16
8
U
0
—
—
—
—
8
—
—
U
—
6
12
U
6
9
19
Alkalinity (iaeA)
"2^5 2B-D 2A-D
0
U
0
0
0 0
0 0
—
0
6
0
0 0
— 10
0
—
0
2 It
..
18
1 1
U o
_
—
—
1 16
0
0
—
0
0
6
h
22
U
"
10
2
—
18
2
0
—
—
—
3U
PROJECT KO.
SO . .
U (*x/l) *•
2-0
68
26
20
22
2S
36
2U
1.2
ii
60
75
30
30
28
U8
UO
30
21
23
?7
29. 5
i.7
2U-D
26
2U
?U
32
70
38
70
75
U2
2a
18
UO
UO
23
26
2U
27
29
..
2A-D
28
32
32
JU
32
50
5U
85
Uo
22
38
38
UO
28
28
28
17
?7
31
—
rote.
o.US
2.1
0.2
O.U
1.15
1.0
0.1
0.3
0.1
0.1
0.6
1.1
0.1
2.2
1.0
0.1
0.1
0.1
0.19
0.36
0.30
0.26
2.88
0.23
lllOlO -
FWW
CR-105
Iron («K/1)
•U 2B-D
P»m)us
O.U
0
0
0
0
0
0
0
0.1
0
0
0
0
0.12
0.13
0.12
0.06
0.03
—
To til
0.35
0.2
0.1
0.2
i.U
1.1
5.5
0.1
0.1
0.1
0.1
0.3
0.3
0.19
0.26
O.U1
0.2U
0.32
0.83
Ferrous
0
0
0
0
0
0
0
0
0
0
0
0
O.OB
0.12
0.10
0.06
O.C3
—
2A-D
Tot«i
O.U
0.2
0.1
o.US
0.1
o.S
0.6
2.0
0.1
0.1
0.1
0.1
0.1
0.1
0.09
0.20
0.32
0.23
0.23
0.75
Ferrous
0
0
0
0
0
0
0
0
0
0
0
0
0
0.02
0.03
0.08
0.03
0.03
w
-------
(Con't) SHEET n WATER AMIJSIS - SHE HO. 2
-J
VO
S*ipUng
9/26/72
10/26/72
11/30/72
1/8/73
2/15/13
3/30/73
1/23/73
5/10/73
6/7/73
7/16/73
8/17/73
10/16/73
10/2U/73
11/23/73
12/19/73
2AU/7U
3A/7U
UA1/TU
U/30/7U
5/28/7U
6/27/7U
B/5/74
now
(cTa)
Swnlee
1U.3
8.6
1U.8
11.5
37.5
30.5
37.1
o.u
trickle
trickle
0.5
6.8
1U.8
16.9
.31-0
1U.2
15.8
10.5
13.3
OS
J*
9_TT 9t^fi 91 «T)
not collectod - no
not collected - DO
U.8 U.9 U.9
U.7 6.5 5.8
5.9 5.0 5.6
5.0 5.2 5.3
U.9 5.0 U.9
5.0 5.1 5.2
5.0 5.1 5.1
U.3 6.8 6.U
6.8 6.2 6.6
U.6 6.9 6.5
U.U 5.8 5.8
U.1 U.1 U.2
h.5 U.6 U.S
U.8 U.8 U.B
U.S U.6 U.7
U.S U.8 U.6
U.6 U.9 U.9
5.0 S.o 5.1
U.6 U.S U.S
4.8 6.2 6.2
Aeldltr (»E/«
4_rt 4D n <*« n
flow
flow
6
6
7
8
U
8
8
8
0
6
10
8
U
2
U
u
u
2
8
10
5
U
6
U
U
8
6
0
0
0
10
8
u
U
2
U
U
2
6
6
U
2
3
U
8
U
6
0
0
0
10
10
2
2
U
u
2
2
8
8
All
*, t]
1
2
0
0
0
o
0
0
30
0
2
0
0
2
0
0
2
6
2
4
[O4n4t^
2
lU
0
0
0
0
0
0
IB
32
U
0
2
U
2
2
U
6
0
42
A* T\
— 2A~D
2
9
0
0
0
0
0
0
1U
36
10
0
0
6
2
U
u
u
0
44
sc
2-0
23
22
17
15
12
31
26
38
S3
to
35
32
26
19
2k
30
2U
23
2U
36
2B-3
23.5
21
17
10
19
2U
29
3U
58
US
UO
27
20
19
22
US
21
26
20
38
I
2A-D
23
21
17
20
17
lU
36
3U
U6
SO
35
30
20
19
23
30
18
2U
20
39
CS-105
Iron f«E/l)
2-0 26-D
0.18 0.02 0.21 0.02
0.10 0.03 0.12 0.08
0.1 <0.1 0.1
-------
TROUGH CREEK LIMESTONE BARRIER INSTALLATION AND EVALUATION
SHEET I
Sampling
Date
IO/2/7O
0/28/70
II/27/7O
I2/3O/7O
1/26/71
0 2/26/71
3/3O/7I
4/28/71
5/28/71
7/2/71
8/5/71
8/31/71
W/l/71
Flow
(Bfs)
I.O-
0.6 +
1.6 •
2.9 »
IS*
12.5 •
1.2*
13.7»
18.3*
3.O*
21.3*
10.7 •
1 .0*
11.7*
N.R.
N.R.
18.0*
3.9*
21.9*
3.75
O.65
4.4
6.7
4.9
11.6
0.75
0.31
1.06
§Ji
3.63
O.O9
O
O.O9
2.81
0.46
3.27
3-U
4.7
5.1
4.6
4.3
4.8
4.4
4.4
4.3
4.2
5.7
4.3
4.9
WATER ANALYSIS - SITE NO. 3
pH Acidity (mg/l) Alkalinity (mg/l)
3-T 3B-D 3A-D 3-U 3-T 3B-D 3A-0 3-U 3-T 3B-D 3A-0
0 9O
4.6 IO
4.6 IO
4 4
43 6
16 O
4.8 10 O
4.7 0( ) O
4 O
4.8 4 O
4.4 6 O
4 0
4.9 0 0
4.7 O O
5.O 2 0
6-3 0 2
4
4.8 K>
4.7 14
6 0
4.8 6 O
5.O O O
4
4.6 — 6
4.4 4.4 44 — —
10
4.6 2
4.6 5.O 0 O O O
2
4.4 6
5.5 6.0 00 0 O
2
__ --
4.9 5.6 14 8
— 6
46 4
5.O 5.4 0 16 O
PROJECT NO. 14010 -FWW
CR-105
Iron (ma./l)
S04 (mg/t) 3-U 3-T 3B-D 3A-D
3-U 3-T 38-D 3A-D Total Ferrous Total Ferrous Total Ferrous Total Ferrous
72 0.35
44 055
48 o.l
8
12 O.I
O.25
0.2
0.4
36 0.4
12 1.2
22 0.8
36 0.55
20 0.8
32 1.9
28 O.25
22 O.25
24 O.I
28 O.I
24 O.I
28 0.3 0
24 O.6 0
40 O.4
28 0.2 O
38 O.I 0
48 40 O.2 O O.3
80 O.I 0
28 O.I O
6O 80 O.4 O 0.4
38 1.3 O
24 O5 0
44 38 1.7 O O.I
7O O.t 0
— — — _ _
6O 6O O.3 O O.8
38 O.I O
24 O.I 0
38 38 O.I O O.I
0
0
O
O
O
-------
TROUGH CREEK LIMESTONE BARRIER INSTALLATION AND EVALUATION
oo
SBEE3LJE
Sampling
Data
II/I/7I
12/l/Tt
1/4/72
2/1/72
2/28/72
3/31/72
4/25/72
5/B/72
7/5/72
7/24/72
8/22/72
9/26/72
Flow
(eft)
t.2
.6
11.8
6.4
2.5
8.9
'1:1
15.7
2*1
HO
15.5
5.9
21.4
9.6
»'.:!
26.3
7.0
33.3
155
5.6
21.1
225
7,0
29.5
1.0
0.8
1.8
0:3
ft
O.II
O.OO
O.II
3-U
4.8
5.1
5.1
4.2
4.7
4.5
3.7
4.4
SI
5.1
5.1
4.3
WATER ANALYSIS - SITE NO 3
3-T
4.6
4.7
4.9
4.3
4.4
5.2
4.4
5.O
53
5.2
5.O
pH Acidity (mg/l) Alkalinity (ma/I)
3B-D 3A-0 3-U 3-T 3B-O 3A-D 3-U 3-T 3B-O 3A-D
- 2
5.1 5.O 4 - — 42
O O
5.4 5.4 O — O 4
6
4
5.1 53 0 — O 6
4.3 4.4 6 12
" 2 2 .
4.7 4.9 - 46
II 0
6 2
4.6 4.6 IO IO 21
13 O
6 0
3.9 3.7 II 13 O O
IO
4.7 4.8 97 -. _
9
5.2 5.1 O 8
IO
6.8 6.1 69 ™ —
K> 2
13 2
7.6 55 5 15 75
IS O
5.5 5.5 II 12 28
PROJECT NO. 14010 -FWW
CR-105
Iron (rng/l)
SO« lma/1) 3-U 3-T 3B-D
3-U 3-T 3B-0 3A-D Total Ferrous Total Ferrous Total Ferrous
34 0.1 O
22 1 .9 O
24 3O O.2 0
4O O.I O
48 O.2 O
48 4O O.I O
01 ° o, o
28 42 O.I O
30 38 °'2 ° 0. 0
44 4O O.I 0
38 0.1 O
50 O.I 0
28 28 O.I 0
29 0.21 0.20
16 O.I9 O.O8
31 3O O.I4 O.K>
25 O.26 0.08
20 O.32 O.O3
25 29 O.34 O.I2
29 O.58 O.O3
2O O.32 O.IO
25 24 O.5O O.O2
33 0.34 O.O6
18 O.I4 O.O6
29 28 O.23 O.O6
39 O.I8 O.O2
13 O.07 O.O3
16 29.5 O.IO O.O8
0.27 —
O.IO —
O.23 —
I4O O.I6 O.O3
116 76 O.2O O.O6
3A-D
Total Ferrous
O.I O
O.I O
O.I O
O.I 0
O.I O
O.I9 0.18
O.32 O.O8
O.45 O.O8
O.2I 0.06
O.O5 O.O3
O.2I
O.O9 O.O2
-------
TROUGH CREEK LIMESTONE BARRIER INSTALLATION AND EVALUATION
ISJ
SHEET HI WATER ANALYSIS - SITE NO. 3
Sampling
Date
IO/26/72
II/3O/72
1/8/73
2/15/73
3/3O/73
4/23/73
5/IO/73
6/7/73
7/16/73
8/17/73
IO/I6/73
IO/24/73
11/23/73
Flow
(eft)
0.41
0.14
0.55
16.0
2.7
18.7
9.9
,5.8
16.3
4 1
20i4
14.3
5.2
,9.5
62.5
12.0
74.5
31.9
4.O
35.9
40.5
5.0
45.5
0.3
84
0:2
Trickle
0.2
O.5
Trickle
0.5
0.6
O.2
0.8
8.8
iai
PROJECT NO. 14010 -FWW
CR-IO5
Iron Gng/l)
DH Acidity (mq/l) Alkalinity (mg/l) S04 (mg/l) 3-U 3-T 38-0 3A-D
3-U 3-T 3B-D 3A-0 3-U 3-T 3B-D 3A-D 3-U 3-T
6.3 13 18
5.3 5 5
6.3 6.6 IO 8
5.1 IO 2
4.8 8 2
4.8 5.O 56
4.7 4 2
5.4 3 5
4.7 4.8 8 6
5.7 8 O
5.O 4 O
5.O 4.8 6 7
48 7 0
5.2 4 0
4.9 4.9 6 6
5.1 4 0
4.9 5 O
5.1 5.3 4 7
5.1 8 0
5.0 8 0
5.2 5.2 66
4.8 8 O
5.O 8 0
4.8 4.8 8 IO
4.5 10 0
4'8 5.5 4.7 8 4 ,0 °
4.8 IO O
6.2 4 O
5.4 6.3 4 6
4.8 4 0
5.6 4 O
6.2 6.8 40
5.0 8 2
45 6 2
4.7 5.2 84
44 4 O
4.2 6 O
4.9 4.2 6 6
38-D 3A-0 3-U 3-T 3B-D 3A-D Total . Ferrous Total Ferrous Total Ferrous Total Ferrous
45 0.20 O.O2
IO.5 O.O4 O.02
5 18 3L5 31 0.14 O.O2 O.IO O.O2
19.5 0.20 O.O6
IO.5 O.O9 0.02
26 22.5 195 O.I9 O.O3 O.23 O.O2
23 O.2I O.O6
12 " O.IO O.O6
2 2 2O.5 21 O.I8 O.O6 0.19 O.O8
22 0.3 CO.2
IO CO.I CO.I
O O 14 24 CO.I CO.I O.2 CO.2
15 0.2
5 O.I
0 O 15 2O 0.2 — O.I
26 0.9
IO 0.3
O O 19 22 0.9 -- O.7
19 CO.I CO.I
14 CO.I 40.1
0 O 14 17 CO.I CO.I CO.I CO.I
22 CO.I CO.I
14
-------
SHEET BE WATER ANALYSIS - SITE NO. 3
TROUGH CREEK LIMESTONE BARRIER INSTALLATION AND EVALUATION
PROJECT NO. 14010-FWW
CR-105
Sampling Flow fH Acidity (mg/l) AlkoUnity (ma/1) SCV (mg/l) 3-U
Dot* (ct«) 3-U 3-T 38-D 3A-D 3-U 3-T 3B-O 3A-D 3-U 3-T 3B-D 3A-D 3-U 3-T 3B-D 3A-D Tbtoi~Fei
3-T
Iron (mg/l)
3B-0
"3AO
Ferrous Total Ferrous Totol Ferrous Total Ferrous
oo
12/19/73 16.5 4.4
3.0 4.5
19.5 4.5 4.5
2/14/74 I as 4.7
5.4 4.7
24.9 4.7 4.8
3/1/74 32 4.7
4O
4.5
4.8 4.7
4/11/74 I6J 4.6
6.1 4.6
22.2 4.6 4.6
4/30/74
4.7
26.2
4.7
4.9 4.9
5/28/74 13.2 4.7
6.1 4.5
19.3 4.9 4.9
6/27/74 16.5 4.8
65 4.5
23.O 4.8 4.8
8/5/74 05 4.8
O.I 4.8
0-6 5.3 5.4
4 4
4 2
4 2
4 2
4 2
2 2
4 6
6 6
O O
2 4
4 2
2 4
4 4
2 4
4 6
6 2O
26
14
23
25
21
25
22
53
14
35
14
23 23
I I
19 22
2O 45
13 14
12 28
14 26
43 43
0.146
0.146
O.146 —
0.146 —
O.I46
0.146
0.146
O.I46
O.I
-------
TROUGH CREEK LIMESTONE BARRIER INSTALLATION AND EVALUATION
PROJECT NO. 14OIO-FWW
SHEET I
Sampling
W/2/7O
D/28/7O
1I/27/7O
12/30/70
2/26/71
V30/7I
4/28/71
5/28/71
7/2/71
8/5/71
8/31/71
KJ/I/7I
1 1/1/7 1
12/1/71
1/4/72
2/1/72
flow
1.2*
0.3"
5.0»
MR.
N.R.
N.R.
MR.
N.R
N.R.
N.R.
8$
3.85
O.O8
O.O3
0.11
3.68
036
4.O4
I8£
1.8
20.4
163
1.5
18.3
19.4
2.0
21.4
•a
15.8
WATER
PH
4.6
6.7
5.0
4.7
4.6
5.5
4.9
5.0
4.6
6.5
4.6
6.8
6.2
7.0
6.8
6.8
5.6
6.7
6.3
6.3
5.3
6.4
5.3
6.7
4.4
5.9
ANALYSIS - SITE NO. 4
Acidity (mg/l)
IO
O
4
2
6
O
16
4
O
2
O
6.5
8.7
0
6.4
5.7
53
6.1
4
5.0 0
Alkalinity (mg/t)
O
12
4
O
0
O
--
O
0
14
28
0
20
12
14
36
18
O
4O
12
IO
80
2O
6
18
18
4
16
40
IO
0
SO* (mg/l)
4.11 A-T 4-H
\J "T 1 ** U
56
36
—
—
22
24
36
28
22
24
28
24
44
30 30
22
22
3O
38
48
38
30
38
22
38
24
30
3O
28
4O
48
42
54
CR-105
Iron (mg/l)
4-U 4-T
Totol Ferrous T otol Ferrous
O.67
0.6
O.I
O.35
0.3
O.3 O
O.I O
O.4 0
0-1 O
0.3 0
O.I O
0.7 0
1.3 O
0.5 0
0.3 0
O.5 0
O.I O
O.I O
O.4 0
0.5 0
O.I 0
0.2 O
O.I 0
I.O O
O.I O
O.3 O
4-D
TOtQi Ferrous
4.4 O
O.I O
O.I 0
O.3 O
O.I 0
O.I 0
O.I O
-------
TROUGH CREEK LIMESTONE BARRIER INSTALLATION AND EVALUATION
PROJECT WO. I40IO-FWW
SHEET H
Sampling
Date
2/28/72
3/31/72
4/25/72
5/B/72
7/5/72
00
Ul
7/24/72
8/22/72
9/26/72
W/26/72
U/3O/72
1/8/73
2/B/73
Flow
(efsl
39.1
£?
55 JO
22.6
3.2
25.8
39.4
£3
o2?
3j6
05
O.5
I.O
OJ6
O.07
O.23
O.57
O.45
1.02
372
42.9
20JO
2.5
225
281
5.7
33.8
WATER ANALYSIS - SITE NO. 4
4-U
4.9
4.7
4.O
4.7
5.6
7.3
7.3
5.9
6.8
43
5.5
4.8
pH Acidity (mg/l) Alkalinity (m)/\)
4-T 4-D 4-U 4-T 4-D 4-U 4-T 4-D
24
62 — 58
5.6 — 32
O.9 I.O
7.1 4 12
5.1 7 1
6.2 " 8 ° 7
45 9 O
1
50 -- 3
5.7 — 6
7
7.1 7
6.5 7
53 5 K) ""
65 4
5 8
6.O 9 25
7.4 5 18
32 II
6JO 16 27
7.1 8 33
63 * O 20
68 O 10
6 2
7.4 O 17
7.1 5 8
4 5
65 0 12
53 0 9
9 O
66 O 1
5.6 3 O
CR-105
S04 (mg/l) 4-U
4-U 4-T 4-D Total Ferrous
3O O.I O
24
24
27 0.19 O.I
20
30
21 ^ 0.33 O.O3
23
17 O.3O O.O6
21
2O
28 O.I4 O.O3
18
26
IL5 O.4I OXD3
235
19.3
O.I2
31 O.I6 O.O6
IL5
23
26 O.IO O.O2
12.5
22
165 O.I8 O.O3
8
14
19.3 O.09 O.O6
12.5
18
17 O.I 3
0.20 0-O6
O.27
0.23 O.IO
0.20 O.O3
O.I2 O.O3
O.I9 O.IO
O.2 <0.2
-------
TROUGH CREEK LIMESTONE BARRIER INSTALLATION AND EVALUATION
00
SHEET ffl
Sampling
Date
3/3O/73
4/23/73
5/IO/73
6/7/73
7/16/73
8/17/73
10/16/73
O/24/73
M/23/73
12/19/73
2/14/74
3/1/74
Flow
fcfs)
23.O
88.8
10.2
99.O
42.2
2.5
44.7
80.7
3.3
84.0
1.6
0.2
1.8
0:2
8;3
Ol7
8:?
0.7
9JO
I.I
10.1
4l'.0
315
44 .0
6.0
5O.O
! WATER
4-U
5.0
5.6
5.6
5.O
6.4
6.9
&3
5.1
4.4
4.7
5.2
5.1
PH
4-f
6.8
6.3
6.7
6.8
6.5
6.8
6.9
6.1
5.6
5.6
5.8
5.6
ANALYSIS -
Acidily
SITE NO.
(mo/I)
4-D 4-U 4-T 4-D
6
O
6.6
3 o
6.O
4
0
6.0
8 o
6.0
0
0
6.2
O
O
6.6
° 0
6.8
4
6
5.9
6
2
5.2
2
4
5.2
4
5.3
2
5.5
1
2
4
6
O
O
O
4
6
2
4
4
4
Alkalinity
4-U
0
0
0
0
4
18
12
4
0
2
6
6
lmg/1)
4-T 4-D
6
2
10
6
10
24
26
20
4
8
14
14
O
0
O
0
2
16
26
6
2
2
6
8
PROJECT NO. 14010 -FWW
CR-105
Iron (mg/l)
SO* (mg/l) 4-U 4-T . 4-D
4-U 4-T 4-D Total Ferrous Total Ferrous Total Ferrous
2O O.I —
3 O.4
10 O.2
26 6.4
10 15
12 6.5
19
-------
TROUGH CREEK LIMESTONE BARRIER INSTALLATION AND EVALUATION
00
SHEET IZ WATER
Sampling
Dote
4/11/74
4/3O/74
5/28/74
6/27/74
8/5/74
Row DH
fcfs) 4-U 4-T
203 StS
3.2 5.8
24.O
26.2 5.7
3.8 6.0
SOX)
20.5 5.7
2.5 5.5
23.O
25.0 5.4
3.O 5.2
28.0
O.8 6.1
O.I 63
O.9
PROJECT NO. I40IO-FWW
ANALYSIS - SITE NO. 4 CR-105
Iron (ma/I)
Acidity (ma /I) Alkalinity (ma/I) SO* (ma/1) 4-U 4-T 4-D
4-D 4-U 4-T 4-D 4-U 4-T 4-D 4-U 4-T 4-D Total Ferrous Total Ferrous Total Ferrous
2 6 3O O —
4 20 30 O —
55 2 6 4O O
4 6 17 0 —
4 24 6 O —
5.6 6 10 16 O
2 IO 18 O
2 22 8 0
5.1 4 6 19 O —
4 6 17 0
8 2O 8 0.4
5O 4 IO 12 O
4 20 16 O
4 22 9 O.I
5.9 8 16 24 O —
-------
TROUGH CREEK LIMESTONE BARRIER INSTALLATION AND EVALUATION
00
00
SHEET I WATER ANALYSIS - SITE NO. 5
Sampling
Date
10/2/70
12/30/70
lt/28/Tl
5/28/71
7/2/71
8/5/71
8/31/71
10/1/71
11A/71
12A/71
l/It/72
2A/72
2/28/72
3/31/72
It/25/72
5A8/72
7/5/72
7/2U/72
8/22/72
Flow
(cfs)
0.2*
N.R.
N.R.
0.2
0.2
0.15
0.12
0.28
0.2
0.3
O.li
O.li
Site
0.5
0.96
1.0
1.15
o.5
0.6
PROJECT NO. 11,010 - FWW
Acidity Alkalinity
PH (mR/l) T^TTT SOU (mRA)
5-U 5-D 5-U
3.1 600
2.9 180
3.0 200
5.7
5.5
6.2
U.3
3.U
3.U
3.6
3.1
2.5
not accessible - Snow
3.0
3.6
3.6
lt.2
3.5
U.2
5-D 5-U
0
0
0
—
0
—
61t
96
108
80
5k
130
151
97
71*
97
93
95
5-D 5-U 5-D
750
Uoo
350
6 310
0 320
2k 310
270
320
320
220
It25
300
0 210
0 310
2k6
21,6
208
0
eft- 105
Iron (rag A)
5-U 5-D
Total Ferrous Total
lit
37.5
20 8
O.li5
O.li
1.8
2.9
2.8
15.5
3.8
2
2.9
2.88
U.80
2.30
3.81,
3.96
676
Ferrous
0
0
0
0
0.3
1.3
0.2
0.1
0.6
0.98
0.20
0.27
0.12
0.12
..
-------
TROUGH CREEK LIMESTONE BARRIES INSTALLATION AlID EVALUATION
(Con't) SHEET II
Sampling
Date
9/26/72
10/26/72
11/30/72
1/8/73
2/15/73
Flow
(cfs)
0.2
0.16
0.53
0.30
Samples
WATER ANALTEIS
pH
5-U 5-D
3.8
3.9
3.3
3.0
Not Collected -
- SITE NO. 5
Acidity AlkaHMty
(mg/1) (mg/1) h (n
5-U 5-D 5-U 5-D 5-U
79
70 30-
190
1UO
Site Not Accessible
PROJECT NO. 1U010 - fWW
CR-105
Iron (m|
iR/1) 5-U
5-D Total Ferrous
290
220
220
180
zA)
5-D
Total
13.0
22.0
10.6
3.6
Ferrous
0.2k
0.18
0.22
0.2J,
00
-------
TROUGH CREEK LIMESTONE BARRIER INSTALLATION AND EVALUATION
vO
o
SHEET I
Sampling
Date
10/2/70
10/28/70
11/27/70
12/30/70
1/26/71
2/26/71
5/28/71
7/2/71
8/5/71
6/31/71
10A/71
11/1/71
12A/71
l/U/72
2/1/72
2/28/72
3/31/72
U/25/72
5A8A2
WATER ANALYSIS - SITE NO
Flow
(cfs)
2.5*
N.R.
N.R.
N.R.
N.R.
N.R.
N.R.
N.R.
N.R.
1.05
6.65
N.R.
50.3
33.3
17.3
71.0
18.3
65.0
3U.O
6-U 6-D
U.7
U.9
U.7
U.3
U.6
U.8
5.7
6.U
6.3
6.1
5.5
5.8
5.9 6.0
6.0 6.0
5.0 5.2
5.3 5.U
U.9 5.o
U.6 U.6
5.7 6.U
. 6
Acidity
6-U 6-D
1U
U
2
6
0
2
—
—
—
6
0
—
—
..
2
__
7 1U
7 8
U 2
PROJECT NO. IU.010 - PVW
(roe A)
6-U 6-D
6
0
0
0
0
U
6
6
—
0
10
18 10
U 6
8
1U 20
1 2
1 1
__ __
s^u (mgA)
6-U 6-D
58
~
--
28
2U
28
32
Uo
U2
95
Uo
22
UO 2U
22 2U
UO 28
38 UU
23 31
23 25
21 16
CR-105
Iron (mgA)
6-U
Total
0.1
0.1
0.5
1.9
1.1
0.65
o.U
0.8
o.U
0.7
0.1
1.0
0.3
0.1
0.1
0.1
0.2U
0.29
0.69
Ferrous
0
0
0
0
0
0
0
0
0
0
0
0.1
0.03
0,65
6-D
Total Ferrous
0.5 0
0.1 0
0.3 0
0.1 0
0.19 0.18
0.21 0.02
O.Ul 0.12
-------
TROUGH CREEK LIMESTONE BARRIER INSTALLATION AMP EVALUATION
(Con't)
Sampling
Date
7/5/72
7/2lo/72
8/22/72
9/26/72
10/26/72
11/30/72
1/8/73
2/15/73
3/30/73
1./23/73
f/10/73
6/?/?J
7A6/73
8A7/73
30A6/73
10/2it/73
11/23/73
12A9/73
SHEET n
Flow
(cfs)
108
5.3
2.0
o.5
2.1
62.5
1|5.0
51.6
35.5
206
62.0
95
2.8
0.5
2.3
1.5
n.5
65.0
WATER ANALYSIS
pH
6-U
5.7
6.6
6.0
5.7
6.0
5.o
5.5
5.2
5.7
5.5
5.9
5-5
5.9
6.1,
5.3
5.1t
5.1
U.8
6-D
6.2
6.8
7.5
6.8
6.2
U.7
5.7
5.2
6.h
5.5
5.9
5.fc
6.1
6.8
5.9
5.1
5.1
h.9
- SITE NO. 6
Acidity
(ME/I)
'6-U
6
6
13
23
If
5
10
7
It
2,
6
Uf
It
2
1»
8
8
It
6-D
7
7
7
8
1
U
It
U
2
6
k
it
0
0
2
6
U
2
Alkalinity
6-U
—
—
7
7
6
5
2
0
0
0
0
0
0
0
0
14
2
2
6-D
—
—
11
17
13
1
ii
0
0
0
0
0
0
0
0
It
2
2
S% (*/
6-U
30
25.5
—
U8
25.5
16
19
17
12
17
111
2k
29
2U
72
U5
27
23
PHOJECT MO,
. ll<010 - P/JW
CR-105
Iron (mp;/3)
T/I) 6-U 6-D
6-D
2?
27
—
514
25.5
16.5
20
lit
12
17
17
22
38 •
38
67
ItO
29
18
Total
0.63
O.Z?
0.23
O.ltl
c.U
0.29
0.29
0.3
0.2
0.5
0.2
0.1
<0.1
0.-2
0.1
0.
0
0.11*6
Ferrous Total
0.03 0.50
0.03 0.33
0.29
0.12 0.36
O.C2 1.06
0.02 0.29
0.10 0.33
<0.2 0.3
0.2
1.2
0.2 <0.2
<0.1 <0.1
- - <0.1
0.3
--
-------
TROUGH CREEK LIMESTONE BARRIER INSTALLATION AND EVALUATION
(Con't) SHEET III
Sampling Plow
Date (of a)
2/lli/7lt
3A/7lt
UA1/7U
V30/7U
5/28/7lt
6/27/7U
8/5/74
U5.5
65
33
38
tt6
ItO
1.3
HATER ANALYSIS •
pH
6-TJ
5.2
5.U
5.5
5.5
5.U
5.3
5.0
6-D
5.2
5.1t
5.6
5.6
5.6
5.3
5.8
- SITE NO. 6
AcidjLty
6-U
2
2
It
It
It
It
4
6-D
U
2
1*
It
2
8
6
Alkalinity
(n
It
It
It
6
It
It
4
ig/lj
6-D
U
6
6
It
6
It
10
SO
S-U
16
17
35
22
23
23
43
HtOJECT NO. U010 - FWW
>KA)
6-D
lit
17
30
26
25
27
43
CR-105
Iron (mf»A)
6-U
Total Ferrous
0.1^6
0
0
0
0
0
0
6-D
Total
0
0
0
0
0
0
0.2
Ferrous
_ —
VO
ro
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-600/2-76-114
3. RECIPIENT'S ACCESSION-NO.
4. TITLE AND SUBTITLE
TROUGH CREEK LIMESTONE BARRIER
INSTALLATION AND EVALUATION
5. REPORT DATE
May 1976 (Issuing Date)
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
S. Curtis Yocum
8. PERFORMING ORGANIZATION REPORT NO
CR-105
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Africa Engineering Associates, Inc.
109 Fourth Street
Huntingdon, Pa. 16652
10. PROGRAM ELEMENT NO.
1BB040. 05-03-0LA-01
11. CONTRACT/GRANT NO.
14010 FWW
12. SPONSORING AGENCY NAME AND ADDRESS
Industrial Environmental Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
13. TYPE OF REPORT AND PERIOD COVERED
Final Report. 6/70-2/75
14. SPONSORING AGENCY CODE
EPA-ORD •
15. SUPPLEMENTARY NOTES
16. ABSTRACT
Six prototype crushed limestone barrier installations were constructed in Trough
Creek in South Central Pennsylvania to demonstrate the neutralizing ability of
this type structure in low-iron acidic streams.
Limestone barrier performance was excellent during periods of low streamflow, in
terms of reducing acidity and raising the pH of the water, but their effectiveness
was marginal at design or average streamflow, and they were ineffective when high
runoffs were experienced. Limestone barrier performance deteriorates after the
structures are initially constructed and placed in operation, because progressive
accumulations of sediment clog interstices between the stones, which lessens the
hydraulic conductivity of the barriers, and surfaces of the stones become coated
with silt, which causes a reduction in reactivity of the reagent (limestone) with
flowing acidic water. The design of limestone barriers should take these factors
into account, and the units should be sized sufficiently large to overcome this
deficiency.
Silted limestone barriers can be restored to porous filtering beds, approximately
equal in performance to initial efficiency, by washing and rehandling the crushed
limestone materials.
7.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS C. COS AT I Field/Group
*Limestone
*Neutralizing
Water pollution
Mines (excavations)
fcAcid mine drainage
Water pollution treatment
Pennsylvania
Trough Creek
Limestone barriers
08/H
13/B
13/M
8. DISTRIBUTION STATEMENT
RELEASE TO PUBLIC
19. SECURITY CLASS (This Report)
UNCLASSIFIED
21. NO. OF PAGES
101
20. SECURITY CLASS (Thispage)
UNCLASSIFIED
22. PRICE
EPA Form 2220-1 (9-73)
93
U.S. GOVERNMENT PRINTING OFFICE: 1976-657-695/5*23 Region No. 5-11
------- |