&EPA
United States
Environmental Protection
Agency
Region 8
1860 Lincoln Street
Denver, Colorado 80295
EPA 908/5-79-002B
June, 1980
Environmental
Impact
Statement
Final
Northglenn Water Management Program
City of Northglenn, Colorado
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EPA - 908/5-79-002B
FINAL ENVIRONMENTAL IMPACT STATEMENT
NORTHGLENN WATER MANAGEMENT PROGRAM
CITY OF NORTHGLENN, COLORADO
EPA
Prepared by
U.S. Environmental Protection Agency
Region VIII
1860 Lincoln Street
Denver, Colorado 80295
Approved b.
Date:
Administrator
June 27, 1980
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ACKNOWLEDGEMENTS
Because of the magnitude of the effort required to produce this
environmental impact statement, it is an impossible task to acknowledge
all of the people and agencies who contributed to the final product.
A heart-felt thanks is extended to the individuals who have contributed
and assisted in the completion of this monumental effort. A special'
thanks is offered to all of the secretaries without whose patience and
long hours the project could not have been competed.
DISCLAIMER
This report has been reviewed by the EPA, Region VIII, Water
Division and approved for publication. Mention of trade names
or commercial products does not constitute endorsement or recommendation
for use.
DOCUMENT AVAILABILITY
This document is available in limited quantities through the
U. S. Environmental Protection Agency, Environmental Evaluation
Branch, 1860 Lincoln St., Denver, Colorado 80295. This document
is also available to the public through the National Technical
Information Service, Springfield, Virginia 22161.
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SUMMARY SHEET
FINAL ENVIRONMENTAL IMPACT STATEMENT
NORTHGLENN WATER MANAGEMENT PROGRAM
CITY OF NORTHGLENN, COLORADO
Prepared by the U.S. Environmental Protection Agency, Rocky Mountain
Prairie Region, Region VIII, Denver, Colorado, with assistance from
Engineering Science, Inc. and Tipton and Kalmbach, Inc., consulting
firms from Denver, Colorado.
A. Type of Action: ( ) Draft EIS
(X) Final EIS
B. Brief Description of the Proposal
The Region VIII Administrator of the U.S. Environmental
Protection Agency (EPA) intends to approve Federal matching funds for
wastewater treatment facilities for the City of Northglenn, Colorado,
through Title II of the Federal Water Pollution Control Act Amendments
of 1972 (PL 92-500), as amended in the Clean Water Act of 1977
(PL 95-217). Eligibility requirements and procedures necessary to
qualify for a grant are set forth in 40 CFR, Part 35, Construction
Grants for Wastewater Treatment Works. The Federal share shall be 75
percent of the total cost found to be eligible, with a portion of the
facility being eligible for 85 percent Federal Assistance as
"innovative or alternative wastewater treatment processes and
techniques" referred to in Section 201(g)(5) of PL 95-217.
The purpose of this environmental impact statement is to present
an evaluation of .the environmental impacts of a plan submitted by
Northglenn proposing to construct a multiple-purpose water resource
project that includes a drinking water supply, wastewater collection
and treatment system, an urban stormwater runoff, collection system and
an agricultural reuse program.
EPA issued an environmental appraisal/negative declaration on
September 29, 1978 which analyzed the Northglenn Plan but left
unanswered critical questions on the impacts to agriculture and public
health. On January 11, 1980, EPA issued the draft EIS which analyzed
these and other issues. EPA has decided to include in the final EIS
additional analysis of water supply alternatives, operational
alternatives, and other potential sites for the proposed facility.
iii
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C. Lead Agency, Project Officer Contact and Address
The U.S. Environmental Protection Agency is the lead agency in a
joint effort with the State of Colorado and the City of Northglenn,
Colorado, to approve plans, necessary permits, and finance or award
grants in order to implement this proposal. Mr. Weston Wilson, U.S.
Environmental Protection Agency, Region VIII is the designated project
officer.
Requests for free copies of this document should be addressed to:
Mr. Weston W. Wilson, Project Officer
U.S. Environmental Protection Agency
Region VIII
1860 Lincoln Street
Denver, Colorado 80295
or call (303) 837-4831.
D. Abstract of the Proposed Action
Northglenn has entered into a water exchange agreement with the
Farmers Reservoir and Irrigation Company (FRICO) that allows
Northglenn to borrow from FRICO up to 7,785 acre-feet per year of
water stored in Standley Reservoir for municipal use. Northglenn is
committed to return 110 percent of the water borrowed for municipal
use to FRICO for agricultural use following wastewater treatment. In
order to satisfy their pay back requirements of 110 percent,
Northglenn proposes to construct a year-round storage reservoir in
Weld County adjacent to their proposed wastewater treatment facility.
The Plan requires the development of a means of replacing the water
borrowed by the City plus 10 percent. This augmentation plan for the
water pay back includes a proposal to collect and treat urban
stormwater, plans to acquire sufficient surface and shallow
groundwater supplies from the South Platte River and proposals to
develop deep nontributary groundwater. Additional surface water
supplies have been acquired through the purchase of agricultural water
rights.
E. Date filed with EPA and listed in the Federal Register;
June 27, 1980
iv
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DISTRIBUTION
1. Governmental Organizations
Advisory Council on Historic Preservation
Arvada, City of
Broomfield, City of
Bureau of Land Management
Bureau of Outdoor Recreation
Central Colo. Water Conservancy District
Colo. Dept. of Health
Colo. Dept. of Natural Resources
Colo. Division of Disease Control
Colo. Division of Highways
Colo. Division of Local Affairs
Colo. Geological Survey
Colo. State Board of Land Commissioners
Colo. State Engineers Office
Colo. State Historic Preservation Office
Colo. State Land Use Commission
Colo. Water Conservation Board
Colorado Northwest COG
Colorado State Clearinghouse
Dacono Planning Commission
Denver Board of Water Commissioners
Denver Regional COG
Denver Water Board
Federal Highway Administration
Firestone, Town of
Frederick, City of
Larimer-WeId COG
Metro. Denver Sewage Disposal District No. 1
National Park Service
Northglenn Nat. Res. Dept.
Northglenn Parks & Rec. Dept.
Northglenn, City of
Thornton, City of
U.S. Army Corps of Engineers
U.S. Dept. of Agriculture
U.S. Dept. of HEW
U.S. Dept. of HUD
U.S. Dept. of the Interior
U.S. Fish and Wildlife Service
U.S. Forest Service
U.S. Geological Survey
U.S. House of Representatives
U.S. Senate
U.S. Soil Conservation Service
U.S. Water and Power Resources Service
Urban Drainage Control
Utah Dept. of Health
Weld County Health Dept.
Westminster, City of
v
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2. Private Organizations
ARIX, Inc.
Adolph Coors Co.
Associated Press
Black and Veatch, Inc.
Boulder Daily Camera
Christian Science Monitor
Colo. Environmental
Colo. Municipal League
Colo. Open Space Council
Colo. Project/T.I.P.
Colo. Rancher & Farmer
Colo. State University
Colo. Wildlife Federation
Consolidated Ditches
Davis, Graham and Stubs
Denver Appropriate Technology Network
Denver Post
Engineering-Science, Inc.
Envirodyne-Jones
Environmental Action of Colo.
Environmental Defense Fund
Farmer-Miner
Farmers Reservoir and Irrigation Co.
Ft. Collins Coloradoan
Ft. Lupton Press
Great Western Sugar Co.
Graeley Booster and Weld County -News
Greeley Journal
Greeley Tribune
Head, Moye, Carver and Ray
Hi-Country News
Holme, Roberts and Owen
Journal of Environmental Health
KBTV-TV Channel 9
KMGH-TV Channel 7
KOA-TV Channel 4
KWGN-TV Channel 2
League of Women Voters
Longmont Times
Loveland Reporter-Herald
Lupton Meadows Pitch Co.
MSC Associates
Moses, Wittemyer, et al.
Musick, Williamson, Schwartz,
Leavenworth and Cope
National Trust for Historic Preservation
National Wildlife Federation
Norton, Underwood and Lamb
Park County Republican
Planet Earthworms, Inc.
Rocky Mountain Center on Environment
Rocky Mountain Consultants
Rocky Mountain Fuel Co.
Rocky Mountain Journal
Rocky Mountain Medical Journal
Rocky Mountain News
Rocky Mountain Orthodontics
Sanders, Snyder, Ross & Dish
Schaefer Farms
Scott, Cox and Associates, Inc.
Sentinel Newspapers
Shaeffer and Roland Engineers
Sterling Journal-Advocate
Trout Unlimited
URS Company
United Press International
W.W. Wheeler & Associates, Inc.
Wall Street Journal
Weisner Preservation Assn.
Weld County Farm Association
Western Ditch Co.
Wright Mclaughlin Engineers
Wright Water Engineers
Yagge, Hall and Evans
Zorich-Erker Engineering
vi
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3. Individuals
Mohammed Al-Ani
J. Robert Allshouse
Tom Araba lam
Marjane Ambler
E. Anderson
Sen. William Armstrong
Jerry Armstrong
James Ayers
Polly Baca-Barragan
Mayor Ode11 Barry
Mayor Al Becker
Jerry Bensema
John R. Beraingham
James Biddle
Adolph Bohlender
Pat Bray
Kenneth Broadhurst
Dave Brown
Charles Buchanan
Donald E. Burback
Lyle Bush
John U. Carlson
Richard Castro
Gary Chambers
George M. Chavez
Frank Cimino
R. Chris Conk1in
Ken Conright
Joseph A. Cope
Howard S. Cox
JoAnn Coxey
Frank Culkin
Joe D'Orazio
John Davoren
James P. Dawson Jr.
Jack DeBell
Laura M. DeHerrera
John DiGregorio
Cliff Dodge
John Doerfer
Jack Eckstein
Dolores Eddy
Toin Elmore
Susan Engelke
Mike Englehardt
Lorraine Eskelson
Bob Farley
Tom Faux
John Fetcher
Eunice W. Fine
John Fiori
Milton Fonay
Jolaine Freitas
Cecile French
Melvin D. Frick
Tad Frost
Dennis J. Gallagher
Robin Garneau
W.W. Gaunt
Ed Geldreich
George Gerhardt
John Gerstle
Bernie Gessner Jr.
W.J. Golth
Ken Gomez
David Goodman
Anne McGill Gorsuch
David Gottlieb
J. Craig Green
Regis F. Groff
Carl 11. Gustafson
John Hall
Mayor Holly Hall
John G. Hamlin
Sen. Gary Hart
Phillip J. Hatch
E. E. Hayes
Elizabeth Hayman
An tone He it
Barbara Hernandez
Paula Herzmark
Donna He trick
William F. Hilsmeier
Greg Hobbs
Harold T. Hodges
Raymond A. Hogan
Barbara S. Holme
Richard Hopkins
vii
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Miller Hudson
Brian Hyde
Henry W. Ipsen
Jan L. Johnson
Dick Johnston
Henry Johnston
Herman Johnston
Roger W. Jordan
James M. Kadlecek
Barry Keene
John Kemp
Walraven Ketellaper
Mary Ellen Kettelkamp
Jack Kintslinger
Henry Knaub
Wayne N. Knox
Frank LaSasso
Lew Ladwig
Jean M. Larson
Daniel Law
Randall Lawrence
John Lee
George Liafet
Ellie Loftus
Richard P. Lundahl
Sherman C. Lyon
Rita MacKenzie
Don MacManus
Jean Marks
Joe Martin
George Matsushima
Doyle McCarthy
Steven A. MeClay
Jack McCroskey
F. Robert McGregor
Linda MeNelly
less McNulty
Beulah Meeker
Frank Milavek
Elton Miller
Gary Miller
Lee Morr ison
John Mulhall
John Musick
Betty I. Neale
Alfred E. Nebring
Marvin Ness
Sylvia Nichols
Tom Norton
Mear1 Nunn
Mildred Nutting
Jules Ornstein
Betty Orten
Don Ostler
Gary Palmer
David Pampu
Frederico F. Pena
Glenn E. Porvack
Melvin A. Potter
Paul W. Powers
Patti Psaris
Gerri Quinlan
Iva J. Renner
Rob Reugman
Stan Rusin
Janice Rusk
John Rutstein
Charles Sabados
Casper Sack
David Salisbury
Thomas G. Sanders
Donald A. Sandoval
Paul Sandoval
Joe Sasaki
Tom Sasaki
William Schaefer
Dan Schaefer
Bev Scherling
Fred Schmidt
Richard Schneider
Bill Schuler
Ron Schyler
Paul See ley
Judith B. Sell
Delbert Shable
Bob Shannon
Howard Shannon
James M. Shepard
Vlll
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Ron & Ellen Shepherd
Gary Shimp
Carl E. Showalter
Ron Siebert
Levi F. Siebert
Cheryl Signs
Feme Skidmore
Bill Smith
Morgan Smith
A.J. Spano
Kathy Spelts
Brent Sponk
Darlene Stephens
Greg Storkebaum
Jim Sullivan
Edward Tagliente
Fred Tapia
John Tarabino
Mary Taylor
Arie Taylor
Mayor Alvin Thomas
Steve Thompson
Marvin Thurber
Arthur Townsend
Nancy Traver
Terrence Trembly
King M. Trimble
Joseph Trostat
Scott Tucker
Charles D. Turner
Al Udin
Roy Van Dyke
Alberta Watada
Bob Weaver
Wayne Weber
Walter Weingarten
William Wells
Robert S. Wham
Chris White
Kenneth Whittaker
Donald B. Wilson
Rep. Timothy Wirth
Laura Withers
L. Duane Woodward
K.R. Wright
Rosie Yeager
Walter A. Younglund
Sam Hanna Zakhem
ix
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Northglenn Water Management Program
City of Northglenn, Colorado
TABLE OF CONTENTS
Chapter 1
Summary and EPA Decision 3
Chapter 2
Purpose and Need 17
Chapter 3
Analysis of Alternatives 21
Introduction 21
The Proposed Project 21
Water Management Options 21
Option 1 22
Option 2 24
Option 3 25
Option 4 25
Alternatives to the Proposed Project 30
Water Supply Alternatives 30
West Slope Water 30
New Appropriations 30
Acquiring Existing Water Rights .... 31
Participation in Existing
Water Projects 31
Environmental Effects of Developing
West Slope Water 31
East Slope Water . f 32
New Appropriations 32
Acquiring Existing Water Rights .... 32
Participation in Existing Projects ... 32
Environmental Effects of Developing
East Slope Surface Water 34
Wastewater Treatment Alternatives 35
Water Resource/Wastewater Treatment Alternative
Cost Analysis 35
Development of Costs 36
Projected User Costs 37
Thornton Water Supply Costs 37
No Federal Action Alternative 41
Chapter 4
Environmental Issues 45
Proposed Treatment Process 45
Treatment Concepts 45
Design Evaluation 46
Facility Performance .47
Public Health 47
Public Health Risks and Irrigation with
Northglenn Effluent 49
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Heavy Metals and Industrial Pretreatment
Requirements 50
Agricultural Issues . 53
Water Supply to Agriculture 53
Nontributary Groundwater 54
Tributary Groundwater 54
Standley Lake Yield 56
Bull Canal Water Distribution 57
Plan for Augmentation and Change of Water Rights . 57
Yield of. Augmenting Rights 58
Administration 58
Ditch Protection 58
Thornton Enclave 59
Grange Hall Creek 59
Legal Issues 59
Summary of Legal Issues 61
Agricultural Productivity 62
Water Availability to FRICO 62
Agricultural Productivity Under the
Northglenn Plan 66
Water Quality 68
Water Supply 68
Irrigation Water Quality . 69
Water Quality Effects on Livestock 73
Groundwater Pollution from Lagoon/Reservoir
Seepage ' . 73
Water Resources 75
Lining of Bull Canal 75
Groundwater Under Lands Taken Out of Production . 76
Taxes and Land Value 76
Changes in Tax Revenue 76
Effect on Land Values Adjacent to Treatment Site . 77
Public Safety 77
Reservoir Safety and Stability 77
Earthquake Analysis 77
Embankment Stability Analysis 78
Seepage 78
Embankment Construction 78
Radiological Emergency 79
Air Quality 80
Growth-Related Impacts 80
Potential Odor Problems 81
Energy
Energy Sources 85
Energy Demands 86
Aesthetics 88
Visual Features 88
Other Issues 88
Noxious Weeds 88
Project Impacts Upon Urbanization 89
Chapter 5 99
Steps to Minimize Adverse Effects 99
Public Health Measures 100
Public Health - Public Contact with Wastewater .... 101
Public Health - Dacono Irrigation System 101
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Public Health - Tailwater Control at Frederick
and Firestone 102
Public Health - Food Crop Production and
Gardens 102
Agricultural Reuse Manual 103
Commitment to Use Effluent for Agriculture 104
Additional Measures to Prevent Groundwater Seepage . . 105
Additional Monitoring Requirements 106
Designation of Management Agency for the
Northglenn Project 107
Management Agencies 108
Management Agency-Weld County or Northglenn? . . . 109
Conditions of the Intergovernmental Agreement. . . 110
Previously Required Mitigating Measures 113
Air Quality 114
Protection of Treatment Capacity 120
Urban Runoff Controls 120
Erosion Control 121
Energy Conservation 122
Water Conservation 122
Radiological Emergency Response Plan 125
Archaeological/Historical Resources 126
Chapter 6 129
EPA Funding Criteria and Analysis 129
EPA Funding Criteria 129
EPA Multiple-Purpose Construction Grants Requirements . 130
Application of EPA Funding to the Northglenn
Project 133
Chapter 7 137
Public Participation and Coordination 137
Public Review of Draft EIS 146
Chapter 8 149
List of Preparers 149
Chapter 9 153
References 153
APPENDIX
Appendix A - Comments and Responses A-l
Appendix B - Description of the Existing Environment B-l
Appendix C - Literature Review of Public Health Risks C-l
Appendix D - Agreements and Applications D-l
Appendix E - Review of Proposed System Performance E-l
Appendix F - Alternative Treatment Site Analysis F-l
Appendix G - Analysis of Changes in Agricultural Productivity . . G-l
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Appendix H - Review of Sludge Management Plan H-l
Appendix I - Evaluation of Efficient Use and Control Plans. . . . 1-1
Appendix J - Cost Analysis and Grant Funding J-l
Appendix K - Draft Intergovernmental Agreement. . K-l
Appendix L - Draft NPDES Permit L-1
Appendix M - South Platte - Deep Well Alternative M-l
Appendix N - Analysis by Northglenn's Engineer of Appendix E. . . N-l
LIST OF FIGURES
CHAPTER 3
Figure No. Title Page No.
3-5 Treatment Sites Evaluated 26
3-6 Alternative Site Study Area 28
CHAPTER 4
4-1 Thornton Enclaves to be Served by Northglenn 52
4-2 Areas of Influence Northglenn Alluvial Wellfield
Proposed Shallow Well Sites 55
4-3 Gross Agricultural Productivity 67
4-4 Worst Case Odor Analysis 82
4-5 Visual Impacts Looking East ' . 90
4-6 Visual Impacts Looking North. . 91
4-7 Present View Looking North from Weisner Subdivision . 92
4-8 Future View Looking North from Weisner Subdivision. . 93
4-9 View Looking Northeast from Interstate 25 and Weld
County Line 94
4-10 Future View Looking Northeast from Interstate 25 and
Weld County Line 95
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CHAPTER 3
LIST OF TABLES
Table No. Title Page No.
3-1 Northglenn's Water Budget 23
3-2 Environmental Evaluation Matrix of Alternative
Treatment and Storage Sites 29
3-3 Costs of Alternative Northglenn Water Supply/
Wastewater Treatment Systems 38
3-4 Average Annual User Charge Northglenn Proposed
Water Management Plan 39
3-5 Cost Summary - Thornton Water Supply 41
CHAPTER 4
4-1 Potential Industrial Discharges in Northglenn
Service Area 51
4-2 Northglenn's Water Budget 60
4-3 Estimated FRICO Farm Headgate Water Deliveries. . . 63
4-4 Surface Water Augmentation 64
4-5 Gross Productivity of FRICO and South Platte
Irrigated Lands Affected by the Northglenn Project. 65
4-6 Total Nitrogen Concentration in Bull Canal 70
4-7 Total Nitrogen Delivery to Sugar Beets and Barley . 70
4-8 Guide to the Use of Saline Waters for Livestock
and Poultry 71
4-9 Recommendations for Levels of Toxic Substances in
Drinking Water for Livestock 72
4-10 Odor Analysis 83
4-11 1960-1964 Hourly Relative Frequency Wind 84
4-12 Comparison of Annual Energy Requirements for
Proposed Northglenn Treatment System and Selected
Alternatives 87
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CHAPTER 6
Table No. Title Page No.
6-1 Grant Estimate 135
CHAPTER 7
7-1 Northglenn Discussion Panel 145
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CHAPTER 1
SUMMARY AND EPA DECISION
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William B. Yeats
The Choice (1933)
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CHAPTER 1
SUMMARY AND EPA DECISION
INTRODUCTION
Title II of the 1977 Clean Water Act established a program to
provide Federal assistance in the development and implementation of
wastewater treatment management plans and the construction of
publically owned treatment works. Federal financing of wastewater
treatment works is implemented in three steps: Step I, facilities
plans, Step II, preparation of construction drawings and
specifications, and Step III, construction of treatment works.
Northglenn funded Step I and Step II plans without Federal
assistance. In September 1977, Northglenn presented copies of their
draft facility plan to EPA. The Plan was revised in November 1977 and
again in March 1979. The State of Colorado Water Quality Control
Division, in March 1978, submitted to EPA certification for
Northglenn's funding. In accordance with regulation, EPA cannot award
a grant until it has approved a facility plan for the proposed project
and performed an analysis of the environmental impacts of the project
under the National Environmental Policy Act. EPA issued an
environmental appraisal/negative declaration on September 29, 1978
which analyzed the current plan but left unanswered critical questions
on the impact to agriculture and public health. Subsequently,
Northglenn modified its plan to include purchase of agriculture rights
from the South Platte River following denial by the State Engineer of
permits for nontributary deep wells. On January 11, 1980, EPA issued
the draft EIS analyzing the environmental impacts of the Northglenn
Plan.
DESCRIPTION OF THE PLAN
The City of Northglenn, Colorado is proposing to construct a
multiple-purpose water resource project that consists of a drinking
water supply, wastewater collection and treatment system, an urban
stormwater runoff collection system and an agricultural reuse
program. This integrated approach to water resource management is
predicated on the following factors:
1) Northglenn's need to provide an adequate source of water for
its users through the year 2000.
2) Northglenn currently is provided a water supply from the
City of Thornton, Colorado. This water supply has, in the
past, experienced concentrations of nitrite that exceed
recommended criteria of the National Drinking Water Interim
Primary Standards.
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3) The Farmers Reservoir and Irrigation Company (FRICO) can
provide an adequate supply of acceptable quality water to
Northglenn and has demonstrated a willingness to participate
in the proposed plan.
Northglenn has entered into a water exchange agreement with FRICO
that allows Northglenn to borrow from FRICO up to 7,785 acre-feet per
year of water stored in Standley Reservoir for municipal use.
Northglenn is committed to return 110 percent of the water borrowed
for municipal use to FRICO for agricultural use. To satisfy their pay
back requirement of 110 percent, Northglenn proposed to construct a
year-round storage reservoir in Weld County adjacent to its proposed
wastewater treatment facility. The Plan also requires the development
of a means of replacing the water borrowed by the City plus 10
percent. This plan for the water pay back includes a proposal to
collect and treat urban stormwater, plans to acquire sufficient
surface and shallow groundwater supplies from the South Platte, and
proposals to develop deep nontributary groundwater. Surface water
supplies have been acquired through the purchase of agricultural water
rights. As defined under the agreement between FRICO and Northglenn,
FRICO is free from any obligation to provide water to Northglenn until
all necessary collection, storage, treatment, and transmission
facilities are constructed and Northglenn has secured a decree from
the Water Court that they have sufficient water to satisfy its
obligations.
Presently Northglenn's wastewater is conveyed by the Thornton
system and treated at the Denver Metropolitan Sewer District No. 1
(Denver Metro). This service is provided by Thornton through
individual contracts that will expire by 1988 with each property owner
in Northglenn. Consequently, Northglenn has negotiated an agreement
with Thornton whereby Northglenn's wastewater treatment will be
provided by Northglenn. Northglenn's revised facility plan (1) makes
the following recommendations for wastewater transport, treatment, and
disposal:
Collection System - In accordance with the agreement reached
with Thornton, Northglenn will make improvements to the
existing collection system to redirect the wastewater flows
to the new Northglenn facility. These improvements include
sealing off several lines and connecting them to a new
interceptor which will convey the wastewater from the City
of Northglenn to the proposed treatment site.
Conveyance System - An interceptor is needed to convey
wastes from Northglenn and small Thornton enclaves within
the service area. The proposed Northglenn Force Main
(46,900 feet) would carry sewage and augmentation water
eight miles north of the City to the proposed plant site.
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Wastewater Treatment - The Facility Plan recommends an
aerated, three cell lagoon system for treatment prior to
storage and discharge.
Storage and Disposal - The Facility Plan recommends a
4362 acre-foot reservoir (Bull Canal Reservoir) to be
constructed in Weld County to provide for winter storage of
the effluent. The treatment and storage sites are located
adjacent to the Bull Canal, approximately 1 1/2 miles
northeast of the intersection of Interstate Highway 25 and
Colorado State Highway 7 in Weld County, Colorado. During
the irrigation season, FRICO has the right to call for
release of water stored in the reservoir. Consequently, the
discharge rate will fluctuate based on the calls made for
water from the reservoir. Chlorination of the effluent will
occur just prior to discharge from the storage reservoir to
the Bull Canal irrigation ditch.
Sludge Disposal - The Facility Plan recommends that sludge
be removed and injected in the surrounding agricultural land.
Description of Options
As the Northglenn proposal includes an exchange of raw water for
treated sewage water, EPA has determined that it is necessary to
evaluate other water supply options as well as wastewater treatment
alternatives. Within the framework of the Plan four options dealing
with water supply have been identified by Northglenn and EPA. Each of
the first three options assumes that wastewater and urban runoff are
conveyed and treated at the Weld County treatment site.
Option 1
Option 2 -
Option 3 -
Option 4 -
Northglenn obtains South Platte surface water
rights and does not obtain any additional
nontributary groundwater beyond their
existing decrees.
Northglenn is awarded 650 acre-feet per year
of nontributary groundwater, thereby reducing
the amount of FRICO borrowed water.
Northglenn is awarded 2300 acre-feet per year
of nontributary groundwater further reducing
the amount of FRICO borrowed water.
An alternative to these plans is for
Northglenn to acquire its future water supply
requirements from FRICO by condemnation or
purchase. Wastewater under this system would
be conveyed to and treated at the Denver
Metro plant with discharge to the South
Platte River.
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A more extensive discussion of the four options and other water
supply alternatives are presented in Chapter 4. Additional water
supply systems evaluated include water from : the Denver Water Board,
the Windy Gap Project, the Colorado Big-Thompson system, a new
transmountain diversion, and expansion of the City of Thornton's
system.
Five problems have been identified by EPA as key issues of this
proposal. These issues are:
• public health
agricultural productivity
protection of potential drinking water supplies
direct impacts of the wastewater treatment facility
elgibility for EPA funding
EPA DECISION
The Northglenn proposal integrates total water resource
management and includes such positive environmental features as
agricultural reuse of effluent, exchange of water with irrigators,
urban runoff controls and water conservation. Therefore, EPA proposes
to approve the Northglenn proposal and to make a grant offer, with
conditions, in the amount of $6,948,000.
This proposed decision is based on an analysis of the following
factors:
1) additional public health control measures beyond those
originally proposed in the plan are required and will be implemented
by Northglenn; however the proposal in the draft EIS to prevent the
sale of raw edible crops will not be required at this time;
2) the project includes certain benefits to agriculture as
compared to the situation if water condemnation litigation had proven
successful;
3) the Northglenn water rights applications, including change of
water rights and the augmentation plan, are a logical approach to
preventing injury to other vested water rights. There are a number of
legal issues to be resolved by the Water Court and some changes to the
water plan as filed are likely;
4) there are no significant direct adverse environmental effects
of the proposal other than a potential odor problem at the treatment
site and in the canal system;
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5) assuming the Bull Canal is currently suitable as a domestic
raw water source, if the proposal is implemented Bull Canal will no
longer be suitable as a source of domestic raw water, since municipal
effluent will on occasion comprise the entire flow in the Bull Canal.
EPA concludes that since the Canal is not presently used for a
domestic water supply, nor has there been any formal request to
designate the Canal for domestic water supply, there is no need to
protect the Canal for water supply;
6) the proposed wastewater system and agricultural reuse system
is eligible for a grant providing partial funding as a multiple-
purpose project using alternative technology as defined under the
Clean Water Act;
7) additional analysis of site alternatives indicates there is
no other site that is more environmentally acceptable. Results of the
water supply analysis indicate other options are more costly while
west slope sources will have less impact upon agriculture. An
analysis of the treatment plant design indicates there is potential
for exceeding the suspended solids limit due to algal growth which
could be reduced through various control measures.
Further detailed explanation of the analysis of these factors
follows:
Need for Additipnj^L Public Health Control Measures
Based upon review of the medical literature, and EPA and Colorado
policies, EPA concludes that additional measures to further protect
public health are necessary. The following three measures will be
included as NPDES permit requirements:
1. Chlorination prior to discharge Oto further reduce the
concentration of fecal coliform bacteria to 200 fecal
coliform organisms per 100 milliliters (ml).
A permit criterion of 1000/100 ml was considered
sufficient for agricultural use where some dilution of
the effluent would occur. Northglenn has agreed to
meet a criterion of 200/100 ml for the discharge into
Bull Canal.
2. Prevention of agriculture tailwater runoff into the Towns of
Frederick and Firestone.
Present agricultural practices combined with a lack of
proper stormwater drainage allows runoff to flow
through these communities. Northglenn will be required
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to intercept and control these flows in order to
further reduce public contact with tailwater runoff
(treated sewage effluent).
3. Complete disinfection of Dacono's nonpotable irrigation
system.
The Town of Dacono operates a nonpotable water system
used for lawn and garden irrigation. The source of
this water is Bull Canal which will, on occasion,
consist entirely of treated wastewater effluent from
Northglenn. In order to minimize the potential for
disease transmission in this situation, Northglenn is
required to disinfect or replace this source of
nonpotable water.
Based upon additional analysis and consultation with the Colorado
Department of Health, EPA concludes it will not be necessary at this
time to require the prevention of sale of raw edible crops grown with
Northglenn effluent. The draft EIS contained the following proposed
grant conditions
In order to receive a grant from EPA, Northglenn will have
to agree to a plan to prevent the public sale or
distribution of raw edible food crops irrigated with
effluent from the Northglenn plant. Northglenn will assist
farmers in marketing the crops to buyers who will process
the crops or Northglenn will otherwise compensate the
farmers for economic losses to the extent of actually
purchasing the vegetables if no other satisfactory solution
can be found. This condition is necessary in order to
minimize the possibility of disease transmission through
ingestion of contaminated vegetables. Northglenn will also
issue and reissue an advisory that will inform farmers and
discourage direct contact with the water and its use on
private gardens.
EPA decided not to impose this condition as the analysis
indicates the potential for pathogen survival through the system is
very low due to reservoir detention time. Pathogen survival will be
further reduced by chlorination of the effluent to meet the fecal
coliform bacteria concentration of less than 200/100 ml. EPA
concludes that public health risks under these conditions are not
significant and that the public health in the reuse area will be
adequately protected. However there is still some unknown risk that
waterborne disease could be transmitted to humans who ingest raw
edible vegetables irrigated with Northglenn effluent.
Currently EPA has not developed criteria or guidelines to
determine treatment criteria for the use of sewage effluent on raw
edible crops. During the next two years the agency will establish
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national guidelines for effluent criteria for unrestricted
agricultural reuse. Upon completion of Agency policy in this regard
and upon permit renewal, Northglenn will be required to comply with
these new guidelines.
If the Northglenn facility is capable of meeting such new
requirements or through a cost-effective analysis it is determined
that operational or design changes are necessary to meet these
requirements, then compliance will be obtained. In the event that the
proposed agency guidelines are unachievable or too costly to achieve
for the Northglenn facility, the imposition of a ban on the sale of
raw edible crops will be reconsidered by EPA. Alternatively
Northglenn could consider purchase of the FRICO water with disposal
upon land owned or controlled by Northglenn.
Regarding the possible irrigation of private gardens, Northglenn
will develop an educational plan that will inform farmers of the
problem and discourage direct contact with the water and its use on
private gardens. In the event that raw edible vegetable crops are
irrigated with Northglenn's wastewater, EPA recommends farmers locate
process markets for the crops.
See Chapter 5 for a complete description of these and other
permit conditions and grant conditions.
Benefits to Agricultural Productivity
EPA analyzed the Northglenn water exchange plan for possible
adverse economic and water quality effects upon agriculture. As
originally proposed, the exchange plan included deep wells as the
entire source of make-up waters. With development of such a new water
source there would not be an adverse effect upon agriculture because
of this new supply. The nontributary well permits were denied by the
State Engineer and this matter is on appeal by Northglenn in Water
Court. Northglenn then purchased South Platte surface water, some of
which is currently used for agriculture, so that their plan could be
implemented without such deep nontributary wells. Under the latter
scheme, it was unclear if indeed there would be any agricultural
benefits to the proposal. EPA decided that further study of the
possible economic impact upon agriculture was necessary.
The agricultural economic analysis has been revised based on
comments received on the draft EIS. The results indicate that by
utilizing South Platte irrigation water as make-up for the FRICO
exchange .a decrease in agricultural productivity of up to $370,000
during a year of normal precipitation could occur along the South
Platte River. However, this is more than compensated by continued
agricultural production in the FRICO system of $1,950,000 in a similar
year. Compared to either direct purchase or successful condemnation
of the FRICO water supply, the proposed Northglenn exchange plan is
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beneficial to the agricultural community. Further, EPA concludes that
properly managed, the benefit of the nutrient values in the sewage
effluent will be a net asset which will enhance agriculture production
in the area at reduced costs.
Under the Colorado Constitution which recognizes domestic
preference, the condemnation proceedings against the FRICO water
supply would likely be successful. Therefore, EPA supports the
proposed exchange as being consistent with EPA policy to protect
environmentally significant agricultural lands. (Chapters 3 and 4
provide further analysis.)
There are also possible adverse impacts to agriculture with
respect to the changes in water quality created by the return of
treated sewage effluent to the Bull Canal. Possible adverse effects
include:
• reduction in sugar beet purity
reduction in barley starch content
EPA concludes, based on comments from affected parties, that
proper management, such as reduction of nitrogen fertilizer
applications and correct scheduling of sewage effluent and Standley
Lake releases, such problems are minor and should not affect crop
production adversely.
Protection of Vested Water Rights
Northglenn must receive approval of the Water Court for a plan of
augmentation in order to implement its proposal. In addition,
Northglenn has purchased various water rights and intends to transfer
such water. This shift in usage of the water in the overappropriated
South Platte system must comply with Colorado's Water Law and receive
approval by the State Water Court.
EPA concludes, based upon expert opinion, that 1) other complex
plans with similar principles have been approved by the Water Court
and this plan can be administered by the State Engineer; 2) the amount
of water obtained from surface sources is reasonable based on historic
ditch diversions and stream depletions; 3) the exchange plan will
sufficiently protect FRICO shareholders; 4) through the Water Court
process, out-of-priority diversions will be properly augmented; 5) the
water rights to be used for augmentation are sufficiently senior for
that purpose; 6) South Platte water users will be compensated for
additional ditch losses; and 7) the Water Court will ensure that South
Platte water users will be protected.
In analyzing the water rights and augmentation plans of the
Northglenn project, a number of legal issues have been identified by
EPA.
10
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These legal issues will be resolved through the judicial
process. EPA concludes that some changes to the water plans as filed
are likely but the probable effect of any subsequent changes during
the court process will likely be limited to requirements for
additional water for augmenting purposes.
Direct Effects of the Proposal
EPA1 s conclusion as to the significance and impacts of direct
adverse impacts is:
Loss of tax base - The projected loss of $8,500 annually to
Weld County and $300 annually to Adams County is a small
decrease in net tax revenues to the two counties. No
mitigation for this tax loss is recommended.
Effect on Adjacent Land Values - A decrease in adjacent
residential values up to five percent is possible with no
change in farmland values.
Groundwater pollution - The proposed clay liner of the
reservoir and lagoon system will minimize any change iff
groundwater quality. Additional construction measures will
be required by EPA and the Corps of Engineers to properly
seal an inactive fault if present. No adverse impact upon
groundwater is predicted.
Odor problems - Under "worst case" conditions which include
the unlikely combination of minimal atmospheric mixing and
malfunction of the aeration system, the Colorado State
Standard for odor could potentially be violated. Noticeable
increases in odor could result.
Reservoir Dam Safety - The design standards meet those
recommended by the U.S. Bureau of Reclamation, U.S. Army
Corps of Engineers and have been approved by the Colorado
State Engineer. No unusual risks are apparent.
Aesthetics - The storage reservoir embankment will be
revegetated and will have a low profile. Therefore, it
should not adversely affect the aesthetics of the area.
(See Chapter 4 for additional analysis of these effects and other
indirect effects.)
11
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Protection for Potential Drinking Water Supplies is Not Necessary
The Bull Canal is not currently used for a domestic water supply
and there has not been any petition to the State to designate this
source for domestic use. Based on very limited data, it does appear
the Bull Canal is currently suitable for a domestic raw water supply.
The Town of Frederick indicated to EPA they intended to use water from
the Bull Canal to augment their present surface supplies. The Town of
Ft. Lupton has informed EPA of its intention to use Sand Hill
Reservoir which receives some flow from Bull Canal as their future
domestic water supply source.
The use of municipal effluent for a domestic source is not
advisable because current treatment technology is unsuitable to treat
such a source. In addition the concentration of nitrates in the Canal
would adversely affect such plans since the concentration will exceed
the National Drinking Water Standard of 10 mg/1. Water containing
such high concentrations of nitrates is not economically suited as a
domestic source. EPA recognizes that this change in water quality
potentially represents a resource lost. EPA concludes that: 1) Bull
Canal discharges to Sand Hill Reservoir are insignificant to the total
inflow and, therefore, this proposal should not adversely affect Ft.
Lupton's intended use of this source and 2) the Town of Frederick
should seek an alternative water supply source.
The Proposal Qualifies for EPA Funding
EPA is presently in the process of developing a method for
funding multiple-purpose projects which involve innovative and
alternative technology in order to apply the incentives provided by
the 1977 Clean Water Act Amendments. EPA determined at the time of
the draft EIS that such projects are eligible for grant awards based
on a formula of 115 percent of the ratio of the present worth cost of
the most cost-effective single-purpose option, to the present worth
cost of the multiple-purpose project. This formula calculates the
fraction of the multiple-purpose project costs which are eligible for
EPA funding. Portions of a multiple-purpose project which involve
innovative or alternative technology are eligible for an 85 percent
grant rather than the normal 75 percent grant. Agricultural reuse of
effluent is defined in the Act as an alternative technology. The
total grant amount is therefore determined by multiplying the fraction
of the multiple-purpose project costs that are eligible times 85
percent for those items necessary for agricultural reuse and 75
percent for all other wastewater elements.
On March 20, 1980, EPA revised the options for funding such
projects and the above procedure is no longer a funding option. This
change is subsequent to Northglenn's application however, and
therefore does not change the procedure as outlined.
12
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For EPA to participate in the funding of a multiple-purpose
project, the following rules apply. The Northglenn proposal meets
these requirements:
1. The cost of the multiple-purpose project must not exceed the
sum of the costs of the most cost-effective single-purpose options
which accomplish the same purposes. (The Northglenn proposal combines
wastewater treatment with agricultural reuse less expensively than two
single purpose projects providing similar functions.)
2. The primary and secondary environmental effects are assessed
in accordance with the NEPA review procedures. (As a result of this
review under NEPA, EPA concludes that there are no significant net
adverse environmental impacts and that net environmental benefits will
result from this project.)
3. The pollution control purpose of the proposed project must be
necessary to meet an enforceable requirement of the Act. (Additional
costs associated with wastewater treatment are necessary for
Northglenn during the 20 year planning period to meet enforceable
requirements of the Act as defined in Denver Metro's discharge
permit. These costs include the need to expand conveyance facilities
and to expand and upgrade the Denver Metro Plant.)
4. There is no purchase of existing facilities with federal
funds. (Northglenn"s purchase of existing water distribution and
collection systems has been eliminated from grant eligibility.)
5. The project meets the definition of treatment works, and the
works are publicly owned. (The wastewater treatment project will be
publicly owned.)
6. The project is consistent with the adopted and approved water
quality management plan. (The Northglenn proposal is in compliance
with the Denver Regional Council of Governments (DRCOG) Clean Water
Plan. Adoption of an Intergovernmental Agreement with Weld County as
required by EPA as a prerequisite to final grant payment will mean the
project is also in compliance with the Larimer-Weld Council of
Governments Clean Water Plan.)
7. The applicant must demonstrate a commitment that effluent
will be applied to irrigated productive agricultural land for the
design life of the project. (Northglenn has committed to a
contingency plan where they will maintain sufficient land to reuse all
water generated by the treatment plant for agricultural irrigation for
the design life of the plant.)
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Results of Additional Analysis
Based on comments received on the draft EIS, EPA expanded the
analysis of the final EIS to include an investigation of other sites,
other sources of water supply, and operational changes that may be
necessary to meet permit requirements.
Three other sites in Adams County were identified as having
suitable locations, soils, and remoteness from residential
communities. While these sites are acceptable environmentally there
is no apparent environmental advantage of selecting another site.
Selection of an Adams County site would eliminate the need to develop
an Intergovernmental Agreement with Weld County which remains a
requirement yet to be accomplished.
Alternative water supply sources investigated included Denver
Water Board (raw water and complete services), Colorado Big Thompson
delivery, Windy Gap Project, and Northglenn's own west slope
diversion. These sources are more costly than the proposed system and
present administrative problems. The option of the City of Thornton
expanding its sources in order to supply Northglenn is evaluated in
this EIS but details could not be produced at this time since Thornton
is still in the planning stages and has yet to define a preferred
water supply source.
There is a difference among experts as to the likelihood of
effluent from the facility meeting the suspended solids limit as
specified in the permit. EPA's analysis of the feasibility of the
proposed system indicates there is substantial likelihood that the
proposed process will not limit carbon, thereby limiting algal
growth. Acceptable operational controls to reduce algal growth
include selective discharge (controlling the depth of discharge) and
the use of introduced fish to consume algae. EPA does not recommend
the use of copper sulphate to control algae since there is a chance
that concentrations of copper could be released which would be
deleterious to crop production.
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To eveAy thing thesis. AJ> a. 4&w
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CHAPTER 2
PURPOSE AND NEED
The City of Northglenn is located in a rapidly growing area
north of Denver, Colorado. Northglenn is largely developed and
surrounded by other incorporated communities. The 1976 population
for Northglenn was 32,000 people in 9,500 residential units. There
are 7,777 connections to the water system within the City to serve
commercial, industrial, public, and residential users. The future
population of Northglenn is limited to the existing available area
of the incorporated City. Northglenn is a "land locked" community
and once its ultimate population is achieved cannot expand to
accept more growth. Northglenn's maximum growth is estimated to
be 42,500 people. The annual growth rate is expected to be 3.1
percent. Northglenn will achieve its maximum growth before
1990. Because Northglenn's population is not expected to increase
above 42,500 this population estimate is projected to be stable
through the year 2000.
Until recently, the City of Thornton owned the water trans-
mission and sewage collection systems in Northglenn. Thornton
was responsible for operation and maintenance, billing of customers,
construction of new lines and all other functions related to the
total water and sewerage system.
Future water supply requirements of Northglenn have been
estimated for a year of average precipitation and a dry year based
on an expected population of 42,500 people. Based on this design
population, the average and dry year water requirements of Northglenn
are 6,840 acre-feet and 7,340 acre-feet of water, respectively.
The raw water quality at Thornton's Columbine Water Treatment
Plant during periods in 1977 and 1978 had nitrite concentrations
that exceeded the recommended limit of 1.0 mg/l(l). Northglenn's
stated position has been that the City of Thornton could not
provide an acceptable water, either in terms of quantity or quality
and proceeded with the development of its water resource management
plan. Thornton corrected the nitrite problems in 1978 by using
break point chlorination (2) and currently is providing Northglenn
a water supply of adequate quality and quantity. Thornton also
indicates that they are currently developing water resources outside
of the Denver metropolitan area to supplement their existing water
supplies. The current position of Thornton is that they can provide
an adequate water supply for themselves and Northglenn (3).
The need to acquire additional water supplies for future growth
in Thornton, Westminster, and Northglenn resulted in several events
which began in 1963. These actions are presented chronologically
below:
17
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• 1963 - Westminister entered into agreement with FRICO for
use and storage of water in Standley Lake.
1973 - Thornton files condemnation proceedings against
individual FRICO farmers.
1973 - Westminster files condemnation proceedings against
FRICO farmers.
1976 - Northglenn enters into an exchange agreement with
FRICO.
1979 (May) - Northglenn and Thornton enter into severance
agreement of water and sewer services.
• 1979 (June) - Northglenn, Thornton, Westminster and FRICO enter
into a four-way agreement which establishes an approach to
cooperative planning for solving water supply problems, and
facilitates the withdrawal of all condemnation suits against
FRICO farmers.
By obtaining water from FRICO, Northglenn has assured itself water
of adequate quality and a dependable water supply source for the future.
The City has also obtained utility independence through the purchase of
its water and sewer systems. In the process of entering into agreements
to insure its future water supply, Northglenn made the commitment to return
110 percent of the water borrowed from FRICO. To achieve this water balance
in the FRICO-Standley Lake Division, Northglenn intends to return its
treated wastewater as part of its commitment to FRICO. As required by
the September 2, 1976 agreement between Northglenn and FRICO, Northglenn
must "collect the water (after municipal use), treat it in accordance with
FRICO's specifications, store it and transmit it back to the FRICO irriga-
tion network for delivery to FRICO stockholders". (4)
The agreements previously discussed are vital steps toward full
implementation of Northglenn1s current water resource management plan.
Equally important steps such as Water Court approval of the Plan of
Augmentation remain to be taken before the plan is fully implemented.
If all obstacles are not overcome, then Northglenn will have to modify
its current plan or use another approach to secure a safe, dependable
source of water. Failure to implement the current plan would also
affect the water supply plans of Thornton and Westminster, possibly
resulting in these cities refiling condemnation proceedings against
FRICO. The success of those proceedings could force Northglenn to
secure other sources of irrigation water, nontributary groundwater,
tributary groundwater, or combinations thereof. The environmental
consequences of such a chain of events cannot be fully determined, and
may be of lesser or greater magnitude than those resulting from the
full implementation of Northglenn's current resource plan.
In effect Northglenn's proposed wastewater treatment facility is
a function of the water supply and exchange program. In order to
implement the exchange, control of wastewater treatment and discharge
is essential.
18
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"Mate panA not economy.
...Expense, and gJieat expense,
may fee an e64enŁtaŁ pant o{
#tue ecowomy."
Edmund Burke
Letter to a Noble Lord (1796)
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CHAPTER 3
ANALYSIS OF ALTERNATIVES
INTRODUCTION
The basis of Northglenn's proposed project is to implement the FRICO
Exchange Contract (May 1979) and the Severance Agreement (June 1979)
under which the City would borrow water from agricultural interests, so
that Northglenn's water supply needs can be met; and to replace the amount
borrowed plus a ten percent bonus with treated domestic wastewater and
water from other surface and subsurface supplies to which the City has
rights. Within the context of Northglenn's project EPA has evaluated
several options and alternatives for water supply and wastewater treat-
ment. Northglenn has three options to meet its water supply requirements
in combination with its exchange program and wastewater treatment plan.
EPA has also evaluated wastewater treatment at the Denver Metro facility
with several water supply options.
THE PROPOSED PROJECT
Northglenn has entered into a water exchange agreement with FRICO
that allows Northglenn to borrow up to 7,785 acre-feet per year of water
stored in Standley Reservoir for municipal use. Northglenn is committed
to return 110 percent of the water borrowed for municipal use to FRICO
for agricultural use following wastewater treatment. In order to satisfy
their pay back requirements of 110 percent, Northglenn proposes to
construct a year-round storage reservoir in Weld County adjacent to their
proposed wastewater treatment facility. The plan requires the develop-
ment of a means of replacing the water borrowed by the City plus 10
percent. This augmentation plan for the water pay back includes a
proposal to collect and treat urban stormwater, plans to acquire sufficient
surface and shallow groundwater supplies from the South Platte River and
proposals to develop deep nontributary groundwater. Additional surface
water supplies have been acquired through the purchase of agricultural
water rights. In addition to Northglenn's proposed project EPA has con-
sidered various water management options and alternative sites for
treatment and storage facilities.
Water Management Options
Northglenn's basic water supply program involves borrowing water
from FRICO, which will be used along with water it owns, to meet its
municipal water requirement. To evaluate the effects of Northglenn's plan,
several options were selected for analysis. These options are schematically
represented on Figures 3-1 through 3-4 (oversized - back of report). The
options include:
1. No deep well supply other than Arapahoe Well No. 7.
2. A deep well supply equal to 650 acre-feet per year.
21
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3. A deep well supply equal to 2300 acre-feet per year.
4. Acquisition of water required for municipal purposes from
FRICO with treatment at Denver Metro. Discharge will be
to the South Platte River.
Shown in Figures 3-1 through 3-4 are estimates of the annual yield
or water requirement at various points throughout the FRICO-Standley
Lake system. Details of the water budget for each of the options are
shown in Table 3-1. The options were analyzed on the basis of depletion
and yield studies provided by the consultants for the City of Northglenn
and independently reviewed by an EPA consultant.
Under terms of the agreement between Northglenn and FRICO, replace-
ment water is required to replace the municipal use loss and to provide
for the ten percent bonus to FRICO. Replacement water will be diverted
from Grange Hall Creek or the tributary well field. Both will have
essentially the same overall depletion effect on the South Platte system
as water will be taken out of priority and augmentation is required to
protect other appropriators. Northglenn proposes that water will
normally be taken first from Grange Hall Creek as pumping costs are less.
The tributary well field will be used to supplement diversions from
Grange Hall Creek.
To provide augmentation rights, Northglenn has purchased land and
water rights in FRICO and along Clear Creek and the South Platte River.
This water will be used when out-of-priority diversions from Grange
Hall Creek or the South Platte tributary well field are made. When this
occurs some lands will be taken out of production.
As discussed previously, Northglenn has filed application for non-
tributary groundwater beneath the City. It is their intention that this
water will form a part of the City's raw water supply as illustrated in
Figures 3-2 and 3-3. The amount of nontributary groundwater used will
reduce the amount of water borrowed from FRICO which reduces the amount
of water to be returned. Because it is nontributary Northglenn will not
have to provide augmentation rights for this water.
Discussed in the following paragraphs are each of the options.
Option 1
Illustrated in Figure 3-1 are the water requirements and augmentation
amounts required under Option 1. Under this option, the only nontributary
groundwater included is that already approved by the State Engineer for
Arapahoe Well No. 7. The total yield of surface water rights owned by
Northglenn and intended to be used for the City's raw water supply system
in a dry year is 1398 acre-feet, and in a year of average water avail-
ability, 2638 acre-feet. Arapahoe Well No. 7 yields 5 acre-feet per year
in both dry and average years. During a dry year, the municipal water
requirement is 7340 acre-feet and Northglenn will need to borrow a total
of 5937 acre-feet from FRICO. Similarly, in an average year with a
requirement of 6840 acre-feet a borrow of 4197 acre-feet will be needed.
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TABLE 3-1
NORTHGLENN'S WATER BUDGET
1988 Conditions
(All values In Acre-feet)
CONDITION
Option 1
Without
Deep Wells •
Dry Avg
Option 2
650 af
Deep Veils
Dry Avg
Option 3
2300 af
Deep Wells
Dry Avg
Option 4
Return to
Metro
Dry Avg
Treated Water Requirements
Household
Irrigation
and Commercial
(lawns and parkŁ
4140 4140
0 3200 2700
4140 4140
3200 2700
4140 4140
3200 2700
4140 4140
3200 2700
Total Water Required 7340 6840
Raw Water Sources
Farmers Highline 69 137
Standley Lake Shares 1074 1504
Church Ditch 135 389
Berthoud Pass Ditch 120 608
Arapahoe Well No. 7 5 5
Proposed Deep Wells 0 0
FRICO Owned Water 5937 4197
Total Water Supplies 7340 6840
FRICO Exchange
Net Amount Rec'd from FRICO 5937
10% Bonus (500 AF min) 594
Reservoir Evaporation 316
Total Payback Requirement 6847 4933
Replacement/Wastewater Return
Sewage - Northglenn 4016 4016
Sewage - Thornton Enclave1 885 885
Sewer Line Infiltration 300 300
Storm Runoff-Grange Hall Crk 1200 0
Tributary well Field 446 0
Total Hater Available 6847 5201
Excess Physical Supply
(Total Available - Payback
Requirement) 0 268
Diversions to be Augmented
Grange Hall Creek 1200 0
Tributary Well Field 446 0
7340
69
1074
135
120
5
645
5292
7340
6137
4016
885
300
936
0
6137
936
0
6840
137
1504
389
608
5
645
3552
6840
4288
4016
885
300
0
0
5201
913
7340
69
1074
135
120
5
2295
3642
7340
4458
4016
885
300
0
_0
5201
743
6840
137
1504
389
608
5
2295
1902
6840
1902
500
236
2638
4016
885
300
0
_0
5201
7340
69
1074
135
120
5
0
6840
137
1504
389
608
5
0
5937(3) 4197(3)
7340
6840
4016 4016
885 885
300 300
0 0
0 0
5201
5201
2563 To Metro Sever
for Treatment and
release to South
Platte River
0 To Metro Sewer
0 for treatment and
release to South
Platte River
Total Augmentation Require-
ments 1646
Augmentation Rights Available 1985
339
Excess Water Rights to Meet
Flow Requirements
2136
2136 1049 2136
1985
2136
(1) An enclave of Thornton will be connected to the Northglenn system.
(2) Excess water available in the system without augmenting which can be used for
irrigation of Northglenn owned FRICO land.
(3) Water obtained from FRICO by purchase or condemnation of additional shares.
23
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The primary reason dry year water requirements for a city are greater
than an average year is because of the need for more lawn watering and
other uses outside the home. The domestic and commercial water demand
and wastewater flow is essentially constant. The total amount of wastewater
estimated for all options is 5201 acre-feet. This includes wastewater
from an enclave of Thornton and sewer system infiltration.
Under this option, in a dry year Northglenn will be required to
return to FRICO 6531 acre-feet of water, including the bonus. The total
replacement water requirement is 316 acre-feet greater because of reser-
voir evaporation loss. The amount of replacement water for an average
year is 4933 acre-feet including 236 acre-feet to cover reservoir evapor-
ation loss.
For Option 1, diversions to be augmented are 1646 acre-feet (1200 acre-
feet from Grange Hall Creek and 446 acre-feet from the tributary well field)
in the dry year. No out-of-priority diversions are required in an average
year. As shown in Table 3-1 the augmentation rights available are 1985 acre-
feet in the dry year and 2136 acre-feet in an average year.
For all of the options, the numbers presented in Figures 3-1 through
3-4 and Table 3-1 are based on the current Northglenn proposals and the
augmentation plan submitted to the Water Court. The final augmentation
plan approved by the Court may be different. In the event of rulings by
the Court adversely affecting the amount of water claimed by Northglenn,
the amount of augmenting rights available may not be adequate and additional
rights may have to be acquired.
Option 2
The schematic representation of Option 2 is shown in Figure 3-2. This
option includes a total of 650 acre-feet of nontributary groundwater as an
inflow to the water system both in dry and average years. The amount of
borrow required from FRICO is 5292 acre-feet for a dry year and 3552 acre-
feet for an average year. The total payback requirement including reservoir
evaporation is 6137 acre-feet in a dry year and 4288 acre-feet in an average
year. The amount of water required to be augmented is 936 acre-feet in the
dry year; no augmentation is required in an average year. Augmentation re-
quirements are less in this option because of the use of nontributary well
water that does not need augmentation.
Option 3
Option 3 is similar to Option 2 except that a total of 2300 acre-feet
nontributary groundwater is available. This option is illustrated in
Figure 3-3. In this option the amount of borrow from FRICO is 3642 acre-
feet in the dry year and 1902 acre-feet in an average year.
Under this option, the deep well supply reduces the amount of borrow
from FRICO so that the wastewater return is more than adequate to meet both
dry year and average year payback requirements and no augmentation is
required. The amount of excess wastewater flow over the required payback
is 743 acre-feet in the dry year and 2563 acre-feet in an average year.
24
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Option 4
Option 4 is an alternative to the exchange plan with FRICO. The
amount of water required to meet Northglenn's municipal requirements
in excess of the Arapahoe Well No. 7 and the yield of the City's owned
water is acquired either by purchase or condemnation from FRICO. Instead
of returning wastewater for agricultural purposes, it is treated at
Denver's Metro Plant and released to the South Platte River. As there
are no out-of-priority diversions in this option, augmenting rights
are not required. The water supply to Northglenn is covered by owned
water rights and water rights acquired from the Standley Lake system.
The depletion due to the municipal use is less than the historic agri-
cultural depletion and therefore no other rights would be injured.
Under this option the 5201 acre-feet of wastewater that is returned
to FRICO under Options 1 through 3 would be available in the South Platte.
Treatment Site Alternatives
The Northglenn water resource management plan initially considered
nine alternative sites for wastewater treatment and storage. At that
time, the treatment and reservoir systems were larger than currently
planned, because the project was sized to provide treatment and storage
for wastewater from both Northglenn and Thornton. In addition, the
reservoir was to be located on a natural drainage thus reducing reservoir
construction requirements and costs. Thus, larger land requirements were
necessary. However, Thornton has withdrawn from participating in the
project, and other changes have been made which effectively reduce land
and other site requirements. A detailed analysis of site alternatives
for the proposed plan is presented in Appendix F.
Seven criteria were used by Northglenn to evaluate the alternative
sites shown on Figure 3-5. These criteria included:
compatibility with surrounding land use
safety of reservoir design
control of seepage losses
underlying mineral resources
operational flexibility
consistency with approved wastewater management plans
severability of system components
The complete analysis of each site is presented in Northglenn's
Application for Site Approval. (1). However, the site analysis presents
a bias toward the selected site, Site 10, because sites one through
nine were evaluated for both a larger and physically different treatment
and storage facility as originally proposed. Site ten was the only
site evaluated for the revised treatment and storage facility.
25
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FIGURE 3-5
TREATMENT SITES
EVALUATED
-------
In view of the above, EPA determined it was necessary to conduct an
alternative site analysis for a wastewater treatment and storage system
identical to the currently proposed Northglenn facility. EPA recognizes
that Northglenn has expended a considerable amount of time and money
investigating and designing for Site 10. An additional alternative site
analysis was performed to evaluate three additional sites for treatment
and storage of Northglenn's wastewater. This analysis is presented in
Appendix F.
The purpose of this analysis was to determine if another site is
environmentally preferred or whether Northglenn's proposed treatment site
is environmentally acceptable when compared to other sites.
This analysis did not develop information to the level of detail
currently available on the proposed site for which final designs have
been completed. The analysis considered all four sites (including Site 10)
from an overview perspective, using existing data. The selection criteria
for the three additional sites were:
site would require no more than three residences to be
relocated
the site is not located in a natural drainage
Based on these criteria the three sites located on Figure 3-6 and
designated as A, B, and C were considered.
All four sites are evaluated using the following environmental
criteria:
geology
groundwater
soils and construction geology
topography and flooding
land use
proximity to the Bull Canal
consistency with land use plans
Additionally, the cost of relocating the proposed facility to one
of the new sites was considered.
All four sites are environmentally suited for construction of
Northglenn's proposed wastewater treatment and storage facility based
on the evaluation summarized in Table 3-2. Differences do exist between
Sites A, B, C and 10 based on the evaluation criteria, but these differ-
ences are believed to be insignificant and can be mitigated by construc-
tion techniques and monitoring. Generally, no one site has the advantage
in all criteria.
21
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FIGURE 3-6
LEGEND
STUDY AREA BOUNDARY
PROPOSED SITE
ALTERNATIVE SITES
RESIDENTIAL DEVELOPMENT
"MAJOR ROADS
-WATERWAYS
Weld County
ALTERNATIVE SITE
STUDY AREA
28
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TABLE 3-2 ENVIRONMENTAL EVALUATION MATRIX OF ALTERNATIVE TREATMENT AND STORAGE SITES
CRITERION
SITE A
SITE B
SITE C
SITE 10
N>
Geology
Faults
Subsidence
SoUs
Permeability
Suitability for Construction
Prime Agriculture Land
Topography
Slope
Flooding Potential
(•roundwater
Dppth
Number of wells Onsite
Land Use
Current
Zoning
No. of Residences
Proximity to Bull Canal
Cost A/
possible oil, gas or coal
No active or potentially
active faults
Probably not of concern:
South of Boulder -
Weld Coal Field
Lou perm., 0.06 - 20 in/hr
Med. to low shear strength
Mod. to high shrink-swell pot.
Yes - if Irrigated
East half 3-5% slope to east
West half 0-3% slope to east
Total elevation change 60 ft.
Slight
Perched: 6-12 ft.
Deep: 70 - 300 ft.
2(1 municipal, 1 other uses)
Agriculture
A-3
None on site;
20-30 within 1/2 mile
200 ft.
$30,247,900
possible oil, gas or coal
No active or potentially
active faults
Probably not of concern
South of Boulder -
Weld Coal Field
Low perm., 0.06- 20 in/hr
Med. to low shear strength
Mod. to high shrink-swell pot.
Yes - if Irrigated
0-3% slope toward southeast
Total elevation change 50 ft.
Moderate
Perched: 8-15 ft.
Deep: 25 - 120 ft.
2(1 domestic, 1 irrigation
and stock)
Agriculture
A-3
None on site;
40 - 80 within 1/2 mile
900 ft.
$30,326,600
possible oil gas or coal
No active or potentially
active faults
Probably not of concern:
South of Boulder -
Weld Coal Field
Low perm., 0.06 - 20 in/hr
Med. to low shear strength
Mod. to severe shrink-swell
pot.
tea - If irrigated
3-9% slope around two knolls
rear center of site;
total elevation change 55 ft.
Moderate
Perched: 8-12 ft.
Deep: 25 - 70 ft.
0
Agriculture
A-3
None on site;
30 - 40 within 1/2 mile
300 ft.
$30,110,400
coal resources, possible oil
or gas.
No active or potentially
active faults
Probably not of concern:
South of Boulder -
Weld Coal Field
Low perm., 0.06 - 20 in/hr
Low shear strength,
Mod. shrink-swell pot.
Yes - if irrigated
3-5% slope around knoll in
southeast corner; 0-3% slope
to northwest corner, total
elevation change 60 ft.
Slight
Perched: 6-10 ft.
Deep: 28 - 30 ft.
0
Agriculture
Agricultural
None on site;
20 - 30 within 1/2 mile
50 ft.
$30,242,300
J./ Does not include costs of delaying project.
-------
It is recognized that time and money have been committed to the
development of Site 10 and that relocation from this site would result
in some loss. However, based on this initial analysis, credits gained
due to a shorter force main and land sales could partially offset the
expenditures to date. If only direct costs (excluding costs associated
with project delay) and environmental aspects are considered, all four
sites are equally suited for the proposed project.
ALTERNATIVES TO THE PROPOSED PROJECT
Northglenn has taken steps to secure its future water supply and
proposes to implement an exchange agreement with FRICO. This water
exchange is an integral part of Northglenn's wastewater treatment facility
plan. EPA has undertaken an analysis of alternative water supply sources,
and their environmental and economic impacts in association with waste-
water treatment alternatives, to compare the proposed project impacts
to feasible alternatives.
Water Supply Alternatives
Municipalities within the Denver Metropolitan Area have several
options available for a water supply source. The basic options consist
of developing a water resource on the West Slope or East Slope of the
continental divide or a combination of both. Water from either the West
Slope or East Slope can be obtained by the following means:
Development of new appropriations
Acquire existing water rights
Participation in existing water development proj ects
A detailed analysis of these alternatives is contained in Appendix D.
Another water supply alternative to those presented in this Chapter was
offered by several opponents. This alternative is discussed in Appendix
M.
West Slope Water
New Appropriations. New appropriations require the creation of new
water rights on the West Slope. However, new appropriations in the
Colorado River Basin are not expected to be easily obtained and not likely
to provide a dependable water supply. West Slope water availability
has been diminishing as a result of growth of the West Slope, planned
transmountain diversions, and perfection of existing rights. Further,
energy development demands are expected to use much of Colorado's share
of the water allocated under the Colorado River Compact. Lower basin
states are expected to exercise their rights under the Colorado River
Compact and Upper Basin Compact. Prior to the year 2000, it is expected
that this new demand will curtail the use of direct flow and storage
water rights junior to 1970 and may even affect rights junior to 1960.
30
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Acquiring Existing Water Rights. Acquiring existing water rights
involves the purchase of water rights that are now physically in existence.
Water rights could be purchased from agricultural users or from an exist-
ing transmountain diverter. A West Slope agricultural water right is
expected to yield from 0.75 to 1.25 acre feet per acre. Based on these
figures, Northglenn would require agricultural water purchases that would
come from 6,000 to 10,000 acres.
Participation In Existing Water Projects. Projects for which North-
glenn may be eligible for participation in with another municipality
include:
Aurora's Homestake Project
Colorado Big Thompson Project
Windy Gap Project
Participation in the City of Aurora's Homestake Project is question-
able at this time. The estimated yield from this project ranges from
10,500 acre-feet in an average year to 3,300 acre-feet in a dry year.
It is unclear if Aurora has water supplies in excess of its own require-
ments, and construction is not projected to be completed until 1988.
Existing stipulations prohibit the use of Colorado Big Thompson (CBT)
water outside the boundaries of the Northern Colorado Water Conservancy
District (NCWCD). Northglenn is outside these boundaries and currently
ineligible for CBT water. Northglenn could potentially be annexed into
NCWCD. NCWCD is concerned with their ability to meet present water demand
projections and past court petitions for water have been defeated on the
basis of impairing the rights of present CBT water users. Furthermore,
NCWCD's present water supplies have been allocated to existing users
within the district. The extent of Northglenn's privileges with a new
subdistrict would only be that of attempting to buy-out existing user's
rights.
Windy Gap is a subdistrict of the NCWCD. Water resources to be
developed by this subdistrict have been allocated. Upon admission to the
subdistrict, Northglenn would have to purchase part of the water allotment
from an existing participant. Currently, no excess water is available
from any of the existing participants. Should Northglenn be able to
acquire its required allotment of water, it is assumed that the water
would be delivered and stored at Boulder Reservoir and pumped through a
new pipeline to Northglenn for treatment. A 5300 acre-foot reservoir would
be required to provide for the five month winter shutdown of Windy Gap.
Environmental Effects of Developing West Slope Water
Each of the West Slope water supply alternatives considered for
Northglenn will result in an adverse environmental impact to Colorado's
West Slope.
The most severe physical impact of transmountain diversions to the
Colorado River basin has been associated with reduction in the flow of high
quality water in the headwaters and the resultant increases in salinity in
the lower reaches of the system. This would create economic impacts to
the existing West Slope municipal, industrial, and agricultural users. Any
new appropriation and transmountain diversions of Colorado River water will
31
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compound these impacts. If Northglenn were to acquire existing water
rights, the associated impacts could potentially be less in terms of
water quality, but would result in a reduction of irrigated agriculture
on the West Slope.
Acquisition of new or existing water rights on the West Slope to
support a water demand on the East Slope is also constrained economically
and politically. In addition to the need to overcome engineering problems
of conveyance the time in developing a water supply is extensive and
institutional arrangements are difficult. The construction of the
facilities needed to deliver the water to Northglenn would have minor
impacts.
East Slope Water
New Appropriations. New appropriations would require new water rights
from the South Platte River. Intense competition exists for any further
allocation of the South Platte River and its tributaries. It is thought
that the allocation of rights on the South Platte have been over extended.
A flow of 5,000 cubic feet per second (cfs) in the South Platte River at
the Denver gaging station is considered necessary to realistically
satisfy the perfected direct flow water rights on the mainstream, even
though the decreed water rights far exceed 5,000 cfs (2). Flows in excess
of 5,000 cfs would represent surplus water available to a new appropriation.
Flows in excess of 5,000 cfs were experienced for only ten years during
the period 1896 to 1975. If the Narrows Reservoir is constructed and its
conditional water right perfected, no surplus water upstream of Narrows
would be available. Because of the unreliability of new appropriations
in the South Platte River Basin, municipal water supplies would not be
feasible and new reservoir storage development would largely be supported
by independent water supplies or by existing decrees.
New appropriations of nontributary water from the deep underlying
aquifer of the Denver Basin are available. Northglenn has applied for
such deep well water rights to supply a portion of their water needs.
Acquiring Existing Water Rights. Acquiring existing water rights on
the East Slope would involve the conversion of agricultural water. The
market place and price of water rights on the East Slope have been changing
drastically in recent years. Municipalities, because of their demands,
are in competition for agricultural water rights and prices for such water
are rapidly increasing. Municipalities have the right to condemn
agricultural water as a last resort to obtaining needed supplies. The
conversion of agricultural water rights to meet municipal demands is
exerting pressures on agricultural water rights and threatening the
present agricultural economy.
Participation in Existing Projects. The existing systems available
for Northglenn to pursue as water supply options are: Denver Water Board,
Thornton and FRICO exchange.
Denver Water Board (DWB) has indicated in the past that it would be
interested in providing Northglenn's water supply, although recent reports
indicate current supplies may not meet present water demands beyond 1998.
32
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The Denver City Charter prohibits water service outside the City limits
if there is not enough water for the inner city water requirements.
Presently the DWB has adopted a policy of exercising caution in entering
into new contracts for outside service and is limiting the number of
annual taps for new service. The DWB has stated that it fully intends
to scrutinize any additions to the service areas of its existing raw
water customers, and contracts for the distribution of raw water supplies
outside the service boundaries will be stopped.
If water service was available from Denver, either raw water service
or treated water service could be considered as an available alternative.
Northglenn currently is receiving water from the City of Thornton
and could continue. Future service would be subject to Thornton's
agreement to provide water and Thornton having sufficient water resources
to provide it. Thornton officials have indicated in the past they are
capable and willing to provide an adequate quality and quantity of water
to Northglenn in the future. (1). However, Thornton's current position
is that they have taken steps to sever their systems and believe it is
not feasible or appropriate for Thornton to reassess its water resource
development plan at this late date. (See May 1, 1980 letter to EPA from
Thornton. Appendix A.)
The present water supply sources for the City of Thornton come from
water rights located in Upper Clear Creek, Lower Clear Creek, South Park
and pumping alluvial groundwater from the South Platte River Basin under
GASP. (GASP, or Groundwater Appropriators of the South Platte River Basin,
Inc. is a non-profit organization of volunteer members formed to provide
replacement water for tributary well pumping in the South Platte River
Basin. GASP procures approximately 30,000 acre-feet of water each year
from various sources, including the Colorado-Big Thompson Project and
Union and McClellan Reservoirs. This water is turned over to the State
to be released as necessary to replace water withdrawn from the South
Platte system between Denver and the Nebraska state line. Currently a
member of GASP is required to replace 5 percent of his total well diversion.)
Thornton currently has a dry year yield of water approaching 20,000
acre-feet per year which is adequate to supply Thornton's and Northglenn's
current demand of about 14,000 acre-feet per year. Northglenn uses about
40 percent of the total or 5,600 acre-feet. Utilization of reservoir
storage with Thornton's direct flow rights could increase the dry year
yield from 4,000 to 6,000 acre-feet. Also, a proposed exchange with
the Burlington Ditch could add another 7,000 acre-feet. Thornton estimates
it will require 20,000 acre-feet per year by the year 2000 without pro-
viding service to Northglenn. Assuming reservoir storage and the
Burlington exchange is ultimately incorporated into the Thornton's water
supply system, Thornton would have a yield slightly over 30,000 acre-feet
which would meet the combined requirements of Thornton and Northglenn
for the year 2000. Thornton's ultimate need is estimated to be 45,000
acre-feet without Northglenn. These estimates are based on current pro-
jections by Thornton. Thornton is in the Water Court on a number of
projects and in the process of finalizing other water supply sources.
According to Thornton officials, planning for Thornton's water supply in
the future consists of the following:
33
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1. The City will continue with an active program of purchasing
additional agricultural rights along Clear Creek.
2. Although Thornton does not currently own any rights on the
West Slope, there is a possibility of a joint venture
development of West Slope water in conjunction with
other water users.
3. Thornton will continue to purchase agricultural rights
in the South Park area.
4. The City has filed for new storage rights in South Park
and has a storage exchange agreement with Aurora in
Aurora's proposed Spinney Mountain Reservoir.
5. Thornton currently has an application pending with the
Water Court to allow an exchange with the Burlington
Ditch along the South Platte River.
6. The possible expansion of tributary wells under GASP
is also an alternative for future supplies to the City.
Thornton is currently developing additional water resources for the
City and has applications in Water Court on a number of various water
rights. Studies and documentation concerning Thornton's present supply
and future plans were not available for this analysis; however, a general
overall discussion with City officials concerning this alternative has
provided information for considering Thornton for Northglenn's water supply.
Environmental Effects of Developing East Slope Surface Water
The most severe environmental impact of developing East Slope water
as a water supply source is a reduction in irrigated agriculture. This
impact is most prevalent to agriculture along the South Platte River and
areas adjacent to Metropolitan Denver. New appropriations of water would
have the least effect on agricultural production. However, new surface
water is not readily available. Furthermore, if the Water Court were to
determine that new surface water required augmentation, it is probable
that augmentation waters would come from agricultural uses.
It is possible that municipalities facing water shortages in the
future will condemn extensive areas of agricultural land for water rights.
Such action will damage an important part of Colorado's economy.
The alternative of Northglenn continuing to receive its water supply
from Thornton as previously discussed must also be considered. Two options
are considered under this alternative. In both options it is assumed
that Northglenn's water rights are purchased by Thornton and incorporated
into their water resources.
Under the Thornton option one. assumes that all of Northglenn's currently
owned water rights are purchased by Thornton. These rights include Clear Creek,
FRICO, and South Platte consumptive uses but not the Northglenn-FRICO
exchange agreement or nontributary groundwater. The total amount of water
34
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available from such a potential purchase is 3,400 acre-feet. The
agricultural impact of purchase of these rights owned by Northglenn and
currently in agricultural production is $600,000 in an average year. This
option does not establish any agricultural impact of Thornton's water
resource developments.
The second option assumes Northglenn's water rights consist of only
Clear Creek, and FRICO but not South Platte, Northglenn-FRICO exchange,
or nontributary groundwater. The Northglenn owned water currently in
agricultural production is 1504 acre-feet in an average year. Transfer
of this water to Thornton would result in a loss of $148,200 of agricul-
tural productivity. To provide the additional water required by Northglenn
it is assumed Thornton would, at a minimum, acquire 5,942 acre-feet from
the South Park area. Utilizing storage in the South Park area, a firm
yield of about 1.0 acre-foot per acre of consumptive use could be realized
with the purchase of relatively senior South Park agricultural rights.
The cost of 5,942 acre-feet may average $2,000 per acre-foot, or a total
of $11.9 million. According to the Colorado Agricultural Statistics the
predominate South Park crop is hay with a yield of less than 1.0 ton per
acre. Assuming an average irrigated production of 1.0 ton per acre and
a price of $60 per ton, the amount of reduced agriculture production in
South Park is $360,000 based on 1979 figures. The total amount of agri-
cultural production lost under this option is $508,200.
The environmental impacts of the Northglenn-FRICO exchange are
presented in the agricultural productivity section of Chapter 4. See
the comparison of the impact of Northglenn's water supply options on
agricultural production in Table 4-5.
Wasj:ewater Treatment Alternatives
Two wastewater treatment alternatives are identified for Northglenn.
The two alternatives consist of: Northglenn's proposed three cell lagoons
followed by reservoir storage and discharge to the Bull Canal, and treat-
ment continued at Denver Metro.
Northglenn's proposed wastewater treatment facility is described
previously in the Chapter. The proposed system is coupled with three
water supply options. Treatment at Denver Metro could be compatible with
all water supply alternatives with the exception of the FRICO exchange
agreement.
WATER RESOURCE/WASTEWATER TREATMENT ALTERNATIVE COST ANALYSIS
A synthesis of water supply and wastewater treatment alternatives
are identified for the City of Northglenn. The Windy Gap Project has the
highest potential for participation by Northglenn of the West Slope alter-
natives considered. Feasible options for Northglenn's participation on
the East Slope are limited to: Northglenn's proposed exchange with FRICO,
Denver Water Board service, and Thornton. The combination of these final
water supply alternatives and the associated wastewater treatment options
which are analyzed on a cost basis are:
35
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FRICO Water Supply
Three options of exchange agreements available. Northglenn
treats wastewater and returns to FRICO.
Purchase of Water Rights. Denver Metro treats wastewater,
South Platte discharge.
Windy Gap Water Supply
Northglenn Wastewater Treatment
Denver Metro Wastewater Treatment
Denver Water Board Water Supply
Denver Water Board Raw Water Contract
Northglenn Wastewater Treatment
Denver Metro Wastewater Treatment
Denver Water Board Full Service Contract
Northglenn Wastewater Treatment
Denver Metro Wastewater Treatment
Thornton Water Supply
Denver Metro Wastewater Treatment
Development of Costs
The evaluation of water resource/wastewater treatment options considers
capital costs, operation and maintenance costs, and salvage value. Present
worth and annual household costs have been calculated.
Costs for each of the alternatives were prepared following EPA guide-
lines. The basic assumptions followed for cost formulation are:
1. Construction costs are based on July,. 1979 prices.
2. Operation and maintenance costs are based on January 1, 1980 prices.
3. Present worth calculations are based on a 20 year period and
a 6-7/8 percentage rate of interest.
4. All systems are sized to serve the ultimate population of
the service area (42,500 people).
5. All operation and maintenance costs are based on projected
1990 flow rates.
6. The present worth and equivalent annual costs are reduced by
the salvage value of various system components in the year 2000.
7. Calculations of salvage values follow EPA cost-effectiveness
guidelines.
8. An average household cost is based on average year water demands.
36
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A summary of calculated cost estimates has been formulated In order
to assess the alternatives and is presented in Table 3-3. A detailed
discussion of the development of these costs is presented in Appendix J.
Thornton as a water supply option does not lend itself to a cost
analysis. This is in part a consequence of the undefined character of
where water would be developed. If Northglenn were to continue with
water service from Thornton it could be assumed the water supply would
come totally from currently undeveloped water resources, developed water
resources, or some combination of both.
The analysis provides a basis for cost comparisons under a variety
of alternatives. The least costly alternative for water supply and
treatment are the options under the proposed exchange project. High
operations and maintenance cost for the other alternatives indicate
higher costs above those of the proposed plan.
Projected User Costs
The cost estimates are for comparison purposes, following EPA
guidelines. The annual charges levied against each household would be
different from the costs presented in Table 3-3 for the water supply
options. Reasons for these differences include:
1. Other revenues such as tap fees and water leasing can
actually reduce the system costs prior to ultimate
development.
2. Financing of future bond expenditures is likely to be
around 9 percent for 30 years if current market con-
ditions prevail.
3. No provision has been made for the future inflation of
construction, and operation and maintenance costs.
4. Some of the options considered are institutionally
inveasible at this time. For instance, agricultural
reuse under the Denver Water Board raw water and
treated water options would be difficult under the
Board's policy to retain dominion over the wastewater
generated from its water supply contracts.
Presented in Table 3-4 are the estimated annual charges per average
household and for a single family residence for the proposed project.
These estimates include provisions for tap fee revenues, inflation through
1990 and short-term water leases.
Thornton Water Supply Costs
Theoretically, Northglenn could reconnect onto Thornton for water
supply service. In order to conceptualize what the cost of this alter-
native may be, several assumptions must be made. It is currently unknown
what costs would be incurred to renegotiate the severance agreement,
what the future rates for connections, taps, and water resource develop-
ment would be, and if current service charges for Northglenn would be
37
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TABLE 3-3
COSTS OF ALTERNATIVE NORTHGLENN WATER SUPPLY/WASTEWATER TREATMENT SYSTEMS
DENVER WATER BOARD WATER SUPPLY
00
FRICO WATER SUPPLY
Capital ($)
Water Supply
Replacement Water
Wastewater
Total
Operation & Maintenance
Water Supply
Replacement Water
Wastewater
FRICO
Agricultural
Reuse (proposed
prelect)
$ 36,268,000 $
7,400,000
17,272,000
$ 60,940,000 $
($/Yr.)
$ 1,066,000 $
55,000
529,800
Denver
Metro
Wastewater
Treatment
56,190,000
0
15,037,000
71,227,000
1,066,000
0
661,000
WINDY GAP
North-
glenn
Wastewater
Treatment
$ 61,136,000
0
17,272,000
$ 78,408,000
$ 1,351,500
0
529,800
WATER SUPPLY
Denver
Metro
Wastewater
Treatment
$ 61,136,000
0
15,037,000
$ 76,173,000
$ 1,351,500
0
661,000
Raw Water
North-
glenn
Wastewater
Treatment
$ 51,834,000
0
17,272,000
$ 69,106,000
$ 2,112,200
0
529,800
Contract
Denver
Metro
Wastewater
Treatment
$ 51,834,400
0
15,037,000
$ 66,871,400
$ 2,112,200
0
661,000
Full Service
North-
glenn
Wastewater
Treatment
$ 54,843,000 $
0
17,272,000
$ 72,115,000 $
$ 2,626,000 $
0
529,800
Contract
Denver
Metro
Wastewater
Treatment
54,843,000
0
15,037,000
69,880,000
2,626,000
0
661,000
Total
Present Worth ($)
Water Supply
Replacement Water
Wastewater
Total
$ 1,650,800 $ 1,727,000 $ 1,881,300 $ 2,012,500 $ 2,642,000 $ 2,773,200 $ 3,155,800
$ 40,798,000 $ 52,798,000
5,900,000 0
19.739.000 _19.6 71,000.
$ 66,437,000 $ 72,469,000
Annual Average Household Cost ($/Yr.)
Water Supply 230 305
Replacement Water 40 0
Wastewater 114 114
Total 384 419
$ 66,969,400 $ 66,969,400
0 0
19.739.000 19.671.000
$ 86,708,400 $ 86,640,400
369
0
114
483
369
0
114
483
360
0
114
474
360
0
114
474
393
0
114
507
$ 3,287,000
$ 65,333,200 $ 65,333,000 $ 71,222,000 $ 71,222,000
0000
19,739,000 19,671,000 19,739,000 19,671,000
$ 85,072,200 $ 85,004,000 $ 90,961,000 $ 90,893,000
393
0
114
507
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TABLE 3-4
AVERAGE ANNUAL USER CHARGE
NORTHGLENN PROPOSED WATER MANAGEMENT PLAN
Year All Households3 Single Family Household
$/yr $/yr
1980 228 272
1981 315 375
1982 340 405
1983 367 437
1984 396 472
1985 428 510
1986 463 551
1987 463 551
1988 463 551
1989 463 551
1990 463 551
a. Average includes both single family and multi-family dwelling units.
39
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different from other Thornton system users located outside the system. For
purposes of this analysis four conditions have been developed. All conditions
assume the following:
current (1980) charges for connection, taps, and water resource
development remain fixed in the future.
all new taps and connections will be 3/4 inch. 683 new taps
and connections will be necessary for the projected population
growth.
current operation and maintenance costs of the water distribution
system will not change.
costs associated with monthly user charges are not factored in to
the analysis.
As it is not known what charges Thornton may assess Northglenn, four
different conditions of cost assumptions have been made. Under Condition 1,
it is assumed that the residents connected to the existing distribution sys-
tem would not be charged connection or tap fees but would be charged for the
water resources development fee. The 683 new taps and connections would be
charged for connection and tap fees as well as water resource development.
The money Northglenn has paid to Thornton to acquire the water distribution
system (associated with the severence agreement - sunk cost) is assumed to
be excluded.
Condition 2 assumes the same conditions as Condition 1 except the severence
costs are assumed to be included.
Condition 3 assumes that all existing and future connections in Northglenn
must pay the entire tap, connection and water resource charges to Thornton
based on Thornton's present fee schedule. Maximum development is estimated
to consist of a total of 8460 taps and connections of various sizes. Sever-
ence costs are assumed to be excluded.
Condition 4 assumes the same conditions as Condition 3 except the severence
costs are included.
These costs are presented in Table 3-5. The conclusion is that total
costs for a Thornton water supply option could vary from the least costly to
the most costly alternative depending upon what conditions for financing would
be required by Thornton.
40
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TABLE 3-5
COST SUMMARY
THORNTON WATER SUPPLY CONDITIONS
Condition 1 Condition 2 Condition 3 Condition 4
Total Capital Cost ($) 25,300,000 45,600,000 93,900,000 114,200,000
Operation & Maintenance ($)
$280,000 x 10.492 2,940,000 2,940,000 2,940,000 2,940,000
(Present Worth Factor)3
Total Present Worth ($) 28,240,000 48,540,000 96,840,000 117,140,000
Annualized Cost ($) 2,690,000 4,630,000 9,230,000 11,160,000
Annual Average Household
Cost ($) 4. 1821-/7352. 3431-/8962- 760 917
1. Existing homes, no tap or connection charges.
2. New homes, tap and connection charges.
3. Present worth of operation and maintenance costs
calculated at 7 1/8% for 20 years.
4. Assumes 3.5 people per household.
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NO FEDERAL ACTION ALTERNATIVE
The "No Federal Action" alternative includes a refusal by EPA to make
a grant to the City of Northglenn for wastewater treatment. Such a denial
by EPA could be based on a finding of ineligibility under the Clean Water
Act or significant unavoidable adverse environmental impacts. Northglenn1s
total water management program is expected to cost $67 million with $6.9
million eligible under EPA regulations. As only 10 percent of the captial
costs and none of the annual costs are expected from the federal government,
Northglenn has indicated to EPA that they will still proceed with the project
in the absence of federal funds. Thus, it is possible that Northglenn will
complete the water management program entirely with local funds should EPA
deny or fail to make a grant.
The consequences of the "no Federal Action" alternative are then very
similar to Northglenn1s proposal except that those grant conditions required
by EPA for additional public health protection or for other reasons need not
be executed by Northglenn.
42
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CHAPTER 4
SIGNIFICANT ENVIRONMENTAL ISSUES
-------
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CHAPTER 4
SIGNIFICANT ENVIRONMENTAL ISSUES
This chapter of the EIS addresses the significant environmental
issues associated with the proposed project. These issues have been
identified through public involvement, the concerns of the parties and
governmental agencies involved, and from the planning, research and
analysis that has been performed. The following discussions summarize
the investigations conducted regarding significant environmental issues.
PROPOSED TREATMENT PROCESS
There are innovative aspects of the proposed wastewater treatment
process which pose certain potential risks including the possible public
health hazards described in this Chapter. The following discussion summarizes
a detailed evaluation which has been performed of the .treatment process
concepts, design and expected facility performance. The full report of
this evaluation is reproduced as Appendix E to this EIS.
Treatment Concepts
The proposed treatment system consists of a parallel series of
three aerated lagoons followed by a storage reservoir. Raw wastewater
will enter the first lagoon and be subject to high aeration and mixing
to essentially convert all the soluble BOD and a major part of the bio-
degradable solids into microbial cells. Average detention time in the
first cell will be twenty-four hours, with essentially no settlement of
solids.
Wastewaters will flow to the second cell where reduced aeration
and limited mixing will take place maintaining the cell mass from the
first cell. As cell mass continues to convert BOD to inert material,
the heavier solids will settle out. The detention time in the second
cell will be four days. It is possible during warm weather that a popu-
lation of nitrifying bacteria, (slow-growing bacteria that convert ammonia
to nitrates), may be established to a limited extent, but the major
nitrification process would occur in the third cell where the detention
time of nine days would be more conducive to the growth of nitrifying
bacteria. The purpose of nitrification is to reduce the amount of carbon
available as an algal nutrient in the final storage reservoir. Algal
growth must be controlled so that the final reservoir effluent suspended
solids concentration will meet discharge requirements. Excessive suspended
solids could also result in a possible source of odors. Although some
aeration will be provided, in the third cell its primary purpose will be
to maintain aerobic conditions and to promote settling of suspended solids.
45
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Pilot studies of the proposed treatment system were conducted from
the end of June to November 10, 1978, to test the validity of the treat-
ment concepts.
An analysis of the concepts, of the data base, and of the results
from the pilot studies revealed several factors which should be considered
in projecting future performance. These are:
The data on wastewater characteristics used to develop
treatment concepts and designs are very limited, and are
limited to existing Northglenn wastewaters. If the proposed
project is implemented,different sources of water supply,
including storm water runoff, may result in changes to the
wastewater characteristics.
Wastewater other than Northglenn?s was used in the pilot
plant studies.
Pilot studies were not conducted long enough to assess
performance during cold weather.
As expected, microbial activity during pilot studies
decreased during lower temperature operation with consequent
reductions in BOD removal. The implication is that there
could be significant BOD carryover, including organic
carbon, into the reservoir, affecting the capability of
maintaining a carbon limiting system for algal control.
It is doubtful that sufficient nitrification in the
second and third cells could be maintained during cold
weather operation.
Design Evaluation
A brief review of the final design has also been conducted. The
conclusions are:
The number and spacing of fixed aerators and amount of air
supplied in each of the three cells is generally satisfactory.
Adjustments in location or supplemental aeration over the
side slopes of the first cell lagoon are suggested. Relo-
cation of aerators away from the third cell lagoon effluent
overflow point would prevent resuspension and carryover of
settled solids in the third cell.
The heat loss calculations for operation during cold weather
appear to underestimate actual heat losses. Consequently,
further reductions in BOD removal and nitrification are
likely during cold weather operations.
The annual energy requirements of the proposed conveyance
and treatment system appear to be higher than the Denver Metro
alternative.
46
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The other aspects of the facility design and underlying
design calculations appear reasonable and acceptable.
Facility Performance
It is anticipated that the effluent limitations that will be
specified in the NPDES discharge permit for the Northglenn facility
will be 30 mg/1 suspended solids, 30 mg/1 BOD^, and 200 fecal coliforms
per 100 ml all for thirty day averages. Based upon the analysis herein
presented and reported in Appendix E, it is concluded that the proposed
Northglenn wastewater treatment system:
1. will likely meet BOD5 limits
2. will likely meet suspended solids limits during
winter operation, but there is a high probability
that effluent limits will be exceeded during summer
months
3. effluent limits of 200 fecal coliforms per 100 ml
will require chlorination of reservoir effluent.
Due to lengthy detention times there is a very low
risk of transmissions of waterborne diseases.
4. It is not probable that a carbon-limiting system can be
maintained in the reservoir. Thus algal blooms are
possible as is the case for almost any reservoir.
In view of the above, several mitigating measures were evaluated
to determine if algal blooms could be controlled. The measures evaluated
included the use of algicides, flocculants, biological controls such as
algae-consuming fish, selective discharge and filtration. Algicides such
as copper sulfate are not acceptable to EPA due to the potential release
of copper concentrations toxic to crops. Flocculants settle the nutrients
temporarily to the bottom, but the nutrients are still available for
subsequent algal growth. Biological controls may successfully reduce
algal concentrations without impact. If an exotic fish species is used,
such as talapia, then screening will be necessary to prevent their release
because release could interfere with native sport fishes. Selective
discharge including depth and timing of effluent release is effective
and environmentally benign. Northglenn will have to monitor suspended
solids and only discharge if concentrations are less than the permit
requirement of 30 mg/1. If the effluent quality is not suitable to
meet the NPDES permit, control of algae will be necessary before dis-
charge. Thus FRICO may be asked to temporarily not call on Bull Canal
Reservoir until Northglenn has controlled any problem due to algal growth.
PUBLIC HEALTH
Potential health risks associated with uncontrolled use of waste-
water conveyed through irrigation canals are:
47
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direct human contact with wastewater which has received
little or no dilution
human consumption of raw edible crops irrigated with
wastewater
The specific risks within the Study Area are:
public exposure/potential contact with effluent in the
Bull Canal and lateral ditches
contact by FRICO farmers with effluent through irrigation
practices
public exposure/contact with effluent at Dacono through
their public irrigation system
public exposure/contact with effluent as irrigation
tailwater in the communities of Frederick and Firestone
ingestion of raw food crops irrigated with effluent on
FRICO farms
raw edible food crops irrigated with effluent offered
for public sale (none presently grown in FRICO-Standley
Lake Division).
Coliform bacteria are the commonly used indicator organisms for
assessing public health risks associated with waterborne disease.
Fecal coliform, bacteria common to warm-blooded animals, are recognized
as positive indicators of potential health risks. The potential for
isolating a specific pathogen per unit volume in 100 percent effluent
is significantly higher than when the same effluent has been volumetrically
diluted. It is therefore apparent that with 100 percent effluent the
potential for infection is greater than with a diluted effluent. The
fecal coliform analysis however, does not differentiate specific pathogens.
During dry year conditions,flow in the Bull Canal may be entirely
sewage effluent, thus increasing the public health risk. The State of
Colorado provides minimal guidance on this problem in their water quality
criteria and standards.
The draft water quality standards proposed by the State include a
standard for agriculture for a fecal coliform limit of 1000 organisms per
100 milliliters (ml). The value of 1000 organisms per 100 ml is based on
an ambient instream condition and is not based on a condition of 100
percent wastewater. In Colorado's final water quality standards the
1000 organisms/100 ml has been omitted for agriculture.
The State separates recreational waters into two classes. Class I
recreation is primary contact and Class II is secondary contact. The
Report of the Committee on Water Quality Criteria specifies that the
primary contact (Class I) category includes such activities as wading
48
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and dabbling by children, swimming, diving, water skiing, and surfing;
where there is a relatively high probability of ingesting small quan-
tities of water and where there is contact with mucous membranes.
Secondary contact (Class II) includes activities in which contact with
the water is either incidental or accidental and the probability of
ingesting appreciable quantities of water is minimal. These include
such activities as boating and fishing.
The Class I recreational criterion is based on data which indicate
a sharp increase in the frequency of detection of Salmonella when fecal
coliform densities exceed 200 organisms per 100 ml in fresh water.
Currently, this is one of the most acceptable relationships which have
been developed between indicator organisms and waterborne pathogens.
This relationship is based on an instream condition and not 100 percent
effluent.
Public Health Risks and Irrigation with Northglenn Effluent
EPA believes that the reuse of wastewater, when out of the control of a
municipality, should be under conditions that provide for the protection of
public health during both agricultural uses and public exposure. A review
of the medical and technical literature regarding such risks is presented
in Appendix C.
In a dry year, irrigation water in the Bull Canal below the North-
glenn discharge will during certain periods consist of 100 percent
effluent with no dilution. It can be concluded from the literature review
(in Appendix C) that public health risks associated with effluent reuse
must be considered on a case-by-case basis. EPA, in its process design
manual for Land Treatment of Municipal Wastewater endorses this approach
by stating, "Safeguards must be established on a case-by-case basis so
that the relative risk of disease transmission in each situation can be
evaluated individually" (1).
Guidance for determining reasonable health safeguards for effluent
irrigation systems in which public exposure is not controlled is provided
from EPA and the Colorado Department of Health. EPA (2) recommends for
areas where the public has access and exposure to the wastewater, that
the fecal coliform limit should not exceed 200/100 ml. The Colorado
Department of Health (3) guidelines for landscape irrigation, because
direct contact with wastewater by the public is possible, also require
that chlorination result in less than 200 fecal coliforms per 100 ml.
The State guidelines also indicate crops grown under these conditions
shall not be raw edible vegetables (3).
These values are not as conservative as the California Code or the
World Health Organization criterion of 2.2/100 ml (total coliform) and
100/100 ml (total coliform), respectively for similar exposure situations.
The Food and Drug Administration currently recommends that raw edible
food crops not be irrigated with domestic wastewater irrespective of the
degree of treatment.
49
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Data on public health risks relative to irrigation with wastewater are
conflicting and are reflected in the lack of uniform requirements or
standards covering such use. The data on public health hazards associated
with uncontrolled access/use of treated wastewater are virtually non-
existent. EPA believes the proposed Colorado primary contact recreational
bacteriologic standard of 200 fecal coliform organisms per 100 ml is a
reasonable bacteriological criterion for discharge of the treated Northglenn
wastewater to the FRICO system. This standard is compatible with un-
restricted public access to the FRICO canal system (4). The proposed
bacteriological discharge level of the Northglenn effluent (4,5) will
provide a relatively high level of pathogen control, but the presence of
some pathogenic organisms in the irrigation water can be expected.
Therefore, EPA and the Colorado Department of Health in the NPDES permit
have required that, prior to discharge, chlorination achieve a level of less
than 200 fecal colonies per 100 milliliters.
Heavy Metals and Industrial Pretreatment Requirements
Heavy metals present in wastewater are generally concentrated in
wastewater sludges. Major heavy metals of concern to the food chain
include cadmium, copper, zinc, molybdenum, selenium, and lead. All of
these are of sufficiently low concentrations in the natural soils and
the projected wastewater effluent that they are not expected to produce
an adverse impact. Soils with high clay content also protect against
the availability of metals for plant uptake. For most toxic metals,
reduced crop yields are experienced at lower levels than those that
create health risks.
A likely source of heavy metals in the wastewater system will be
from industrial discharges. A condition to obtaining construction grant
funds is that the applicant implement a sewer use and pretreatment
ordinance. Northglenn must have such an ordinance approved prior to the
award of a construction grant for the new treatment facility. A portion
of Thornton will also be served by Northglenn and this area will require
a similar ordinance as required by the May 4, 1979, Northglenn-Thornton
agreement (6).
The purpose of a sewer use ordinance is to prevent discharge of
materials into sewer lines which would create a discharge violation or
make treatment unreasonably costly. A list of these materials, critical
concentrations, and treatment requirements will be delineated in the sewer
ordinance.
Although the City of Northglenn is comprised largely of residential
units, there are some commercial and industrial facilities which potentially
may discharge harmful wastes. A list of dischargers in the Northglenn
service area is given in Table 4-1. A review of these facilities in
Northglenn indicates that car washes and laundries are the predominant
potential sources of industrial waste. An evaluation of these wastes
on a case-by-case basis is necessary to determine if pretreatment is
warranted. The proposed EPA treatment and control technologies for such
facilities are:
50
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Dissolved air floatation,
Coagulation/Settling/Filtration,
Water Recycling, or
Polishing Filters - Multi-Media and Carbon
The Thornton areas served by Northglenn are indicated in Figure 4-1.
A review of zoning ordinances indicates that the majority of these areas
are classified as commercial and industrial, with minor sections classified
as residential development. As in Northglenn, laundries are the major
industrial dischargers in Thornton.
Based on review of existing and proposed development it is concluded
that industrial wastes are and will be a very small component of the
wastewater from the Northglenn service area. The wastewater from the
potential industrial and commercial establishments should be evaluated
but it is unlikely that it will significantly affect the operation of
the treatment facility, the effluent quality, or adversely affect sludge
disposal. EPA concludes that the expected heavy metal concentrations in
the effluent and sludge will not present any significant health risk.
TABLE 4-1
POTENTIAL INDUSTRIAL DISCHARGERS
IN NORTHGLENN SERVICE AREA
NORTHGLENN
Discharger
Whistle Stop Exxon
Huron Texaco
Robinson's Standard
North Washington Conoco
Clean-o-mat
Silver State Cleaners
Silver State Cleaners
and Laundry
Robo of Northglenn
THORNTON
Triple A Coin Op
Gigantic Cleaners
Description
Service Station w/car wash
Service Station w/car wash
Service Station w/car wash
Service Station w/car wash
Laundromat
Dry Cleaners
Dry Cleaners and laundromat
Car wash
Laundromat
Laundromat
51
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'FTflTTR'P' A-1
I/
I/
1
NORTHGLENN
x-Northglenn area
to be served
by Thornton
-Thornton wastewater
service area to be
served by Northglenn--
5000
IOOOO FEET
SCALE
THORNTON ENCLAVES TO BE
SERVED BY NORTHGLENN
52
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AGRICULTURAL ISSUES
EPA has established policy designed to help protect environmentally
significant agricultural lands (7). The policy is to protect signif-
icant agricultural land from irreversible conversion to uses which
result in its loss as an environmental or essential food production
resource.
The Northglenn plan is designed to provide a benefit to
agricultural productivity. All elements of the plan, water supply,
wastewater treatment, and reuse, are closely integrated x^ith agricul-
tural practices of both the South Platte River and FRICO-Standley Lake
Division.
It is a major goal of this document to determine if the proposed
plan is consistent with EPA's agricultural policy. The determination
of consistency will be based on a comparative review of changes in
agricultural productivity in FRICO and the South Platte for the options
evaluated. Also evaluated will be the effect upon agriculture of the
comparative changes in irrigation water quality in the Bull Canal for
the various options. See Appendix G for a detailed explanation of these issues.
The projected future water quality of the Bull Canal will exhibit
an increase in nitrogen which will be beneficial to nitrogen-demanding
crops. However, sugar beet and malt barley are nitrogen sensitive crops.
Nitrogen uptake by sugar beets is approximately 80 pounds per acre, and
the barley uptake is about 75 pounds per acre.
When nitrogen deliveries exceed nitrogen uptake demand of sugar
beets, a reduction of the percent sucrose content and purity occurs.
This reduces the marketability and/or market value of the crop. Great
Western Sugar Company in its contract with growers specifies that after
July 15 the growers are prohibited from further nitrogen application.
This provision assures that sugar beets will meet specifications for
effective sugar recovery. Great Western has indicated that with proper
water management Northglenn's effluent will provide a nutrient benefit
to crops*.
Nitrogen uptake by barley affects the protein and starch content.
Again, marketability is reduced and entire shipments may be rejected by
the processor if excessive nitrogen applications have severely reduced
the starch content.
Water Supply to Agriculture
Analysis of the Northglenn Water Management Plan has indicated a
number of potential issues which could affect the operation of the plan
and the amount of augmentation water ultimately required by the City.
53
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Nontributary Groundwater
Nontributary groundwater (water that is not connected with the surface
stream system) is available within the underlying aquifers of the City of
Northglenn in the Arapahoe and Laramie-Fox Hills formations. Northglenn
has one well, Arapahoe Well No. 7, completed into the Arapahoe formation
which is estimated to yield a small supply of 5 acre-feet per year. Infor-
mation provided by Northglenn's engineers, Wright Water Engineers, Inc.,
based on a report prepared by John Romero of the State Engineer's office
indicates there is approximately 100,000 acre-feet of water in the Laramie-
Fox Hills aquifer beneath the city limits of Northglenn and 130,000 acre-
feet in the Arapahoe Formation available for appropriation. (8) This
results in an estimated annual withdrawal rate of between 2100 and 2300
acre-feet per year. (One percent of the 230,000 acre-feet estimated
to be available as deep nontributary groundwater.) The study generally
encompassed a wide area and the amount of water actually available will
be determined after the wells have been drilled.
There are a number of issues involved with nontributary groundwater
as a source of supply. The primary issue relates to Northglenn's right
to appropriate water beneath the City limits but under land not owned by
the City without the consent of the property owner. Other issues involve
questions of the amount of water actually available and whether the water
is in fact nontributary. These issues are currently before the Water Court,
The effect of any rulings which reduce the quantity of water available
from the aquifers beneath the City for use by Northglenn will require
more borrowed water from FRICO by Northglenn or the acquisition of other
surface waters.
Tributary Groundwater
One option of Northglenn's Water Management Plan is to obtain replace-
ment water from the South Platte River system from a series of shallow
alluvial wells generally located in Section 17, T2S, R67W (9). Illustrated
on Figure 4-2 are the proposed sites and the expected area of influence.
The tributary well field will be used by Northglenn primarily as a supple-
mentary source; the primary replacement water supply will be diversion
from Grange Hall Creek.
Northglenn has applied for underground water rights for five shallow
wells to be constructed on six potential well sites. The wells are expected
to be 35 to 40 feet deep with a capacity of 720 gallons per minute.
Depletions to the South Platte River system will be fully augmented
as if well pumping was a surface diversion. The time delay of the effect
of pumping a well located a distance from the river will be accounted for
in the plan for augmentation currently pending in the Water Court. Through
the Water Court process, Northglenn will have to provide augmentation
water to the river at times when well pumpings actually deplete the surface
flow. During the winter months the augmentation water will be provided
from storage releases.
54
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FIGURE 4-2
SOURCE: Wright Water Engineers
AREAS OF INFLUENCE
NORTHGLENN ALLUVIAL WELLFIELD
PROPOSED SHALLOW WELL SITES
55
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Standley Lake Yield
During the period from 1941 through 1976 the average yield to the
FRICO farmer from the Standley Lake system was 4.9 acre-feet per share.
The lowest yield was 1.3 acre-feet per share in 1955 (10). According
to a study by Blatchley and Associates, the amount of delivered water
in 1932 was about 0.80 acre-feet per share, the lowest on record (11).
In contrast, Northglenn has projected a future dry year yield of 5 acre-
feet per share with an average yield of 7 acre-feet per share. This
estimate is predicated on a number of assumptions:
1. The Bull Canal system will be lined, reducing the ditch
loss from an historical average of 40 percent to about
10 percent in the future.
2. Losses in Big Dry Creek which historically have been
between three and five percent (12) will be zero in the
future and there may be an increase due to urbanization
of the area adjacent to Big Dry Creek, which would
increase runoff yields.
3. The Cities of Northglenn, Westminster and Thornton now
own approximately 39 percent of FRICO's share and will take
their water by pipeline directly from Standley Lake (13).
This increase in City ownership reduces losses associated
with agricultural use.
4. There is a better prediction of dry year yields based
on improved snowpack estimates. This could result in
a more efficiently managed water supply.
5. Previous studies have apparently been based on poten-
tially erroneous data relative to the Croke Canal (a
feeder canal from Clear Creek to Standley Lake).
Revised studies by Northglenn's consultants have been
based upon the change in reservoir water levels.
6. The reservoir was enlarged in 1965, and the larger
volume will allow more efficient water use. In the
dry year of 1977, which can be compared to 1954 —
the driest on record since 1941 — the unit release was
5.9 acre-feet per share (14).
For the analysis of the Northglenn water management plan, the
yields of 5 and 7 acre-feet per share for dry and normal years,
respectively, are considered reasonable by EPA. This will also be
approximately equal to the yield to the farmers because of lining the
Bull Canal system and the 10 percent bonus provision in the Northglenn/
FRICO exchange agreement. In the event the Bull Canal system is not
lined, a yield of 5 acre-feet per share at the reservoir will be about
3 acre-feet per share delivered to the farm headgate.
56
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One consideration which may reduce or have a negative impact on
the yield of Rtandley Lake in the future is that the Croke Canal is
the primary supply to Standley Lake and, with a 1902 appropriation date,
is a relatively junior water right on Clear Creek. The Croke Canal
generally is in priority only during winter and spring runoff periods.
Because of increased efficiency in water use by other senior appropriators
within the Clear Creek and South Platte River Basin, concern has been
expressed that the yield of the Croke Canal may continue to diminish (12).
Bull Canal Water Distribution
Through the Northglenn/FRICO water exchange plan, payback water
will be returned to the Bull Canal at the Bull Canal Reservoir site
approximately 13 miles from the headgate of the Bull Canal. In 1979,
there were 401 farmer shares upstream of the point of payback return
and 1049 farmer shares downstream (15). Under certain flow conditions
with some of the options considered, there is not sufficient water
available in Big Dry Creek at the headgate of the Bull Canal to give
the upstream shareholders the same yield as those downstream of the point
of return. In a mutual ditch company, the share yield throughout the
system is to be equal. Northglenn has stated, although no provision is
made in any of the agreements or within the augmentation plan, that if
such a shortage occurs, they will make water available either from
holdover storage in Standley Lake, by pumping to the upper shareholders
from the Bull Canal Reservoir, or by other means to insure the same yield
upstream as downstream of the point of return.
Plan for Augmentation and Change of Water Rights
The contract between Northglenn and FRICO and the water rights
owned by Northglenn provide a physical water supply to the City. In
addition to the physical supply, it is necessary to insure there is a
legal right for the City to use the water. Because the South Platte
Basin is overappropriated, application to the Water Court for a new
municipal water right for Northglenn would not provide any water on a
legal basis except during certain limited times of the year when free
water would be available.
The Northglenn Water Management Plan has three essential components
in terms of providing Northglenn a legal water supply. These are as follows:
a. Change in water rights
b. Plan for augmentation
c. New water rights
Northglenn has filed a number of new water rights which form a part
of the plan for augmentation. The filing for nontributary groundwater
from beneath the City is pending with the Water Court.
57
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The change of water right filing for the Northglenn Plan involves
changing the decrees of the Church Ditch, Farmers High Line Canal, East
Lake Water Company (carried in and served by the Farmers High Line Canal)
and the Berthoud Pass Ditch.
The plan for augmentation includes as rights to be augmented : the
Northglenn Reservoir (proposed); the Bull Canal Reservoir; the South
Platte tributary wells (Nos. 1 through 5); and the Grange Hall Creek
diversion at Irma Drive. Water rights which will be used for augmentation
include the Lower Clear Creek Ditch, Burlington Ditch, Burlington Reservoir,
Fulton Ditch, New Brantner Extension Ditch Company, Lupton Bottom Ditch
Company, Brighton Ditch, and deep non tributary wells. Water rights on
Grange Hall Creek and some storage reservoirs are also included.
The documents requesting approval of Northglenn's water supply plan
were filed with the Water Court in Division 1, the South Platte River
Basin, on August 31, 1979. Other water right users had until October 31,
1979 to protest the action and identify any rights which may be injured
by Northglenn's plan. There will then be a period of discussion and
negotiation between Northglenn and objectors to eliminate or reduce the
number of issues. It is unlikely that a consent decree covering all
issues can be negotiated and the case will be heard by the water judge.
Yield of
The yield of the water rights to be used for augmentation was
reviewed from preliminary engineering studies provided by Northglenn.
EPA concludes that it appears that the water rights represent sufficiently
senior rights for augmenting purposes. Water used for augmentation comes
from lands historically in agricultural production. Only the agricultural
consumptive use can and will be used for augmentation.
Administ ra t ion
The plan for augmentation is not specific to the details of the
plan operation and administration. The State Engineer normally assigns
only one Water Commissioner to each stream or stream segment for admin-
istration. The Northglenn augmentation plan as well as operation of
the water supply system is very complex. Operation and proper monitoring
will require measuring devices throughout the system and may even require
measuring crop consumptive use as well as reservoir evaporation. The
State Engineer's office has indicated to EPA that it needs at least one
additional employee to properly administer Northglenn's proposed plan.
Ditch Protection
When shares in a mutual ditch company are used for augmenting
purposes it is necessary to either transfer the water out of the ditch
or divert water from the ditch back to the river source. The other
ditch users must be protected from injury and may suffer a loss of water
were Northglenn to transfer its shares out of the ditch entirely.
Northglenn has stated they will work with the individual ditches to work
out a means of insuring that the remaining ditch shareholders are protected.
58
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This can be accomplished through the use of augmentation stations, by
diverting water from the ditch back to the stream, or by leaving a
certain percentage of their water right permanently in the ditch
equivalent to the pro-rata share of seepage loss. The balance of the
water right would be either left in the stream or changed to a new
point of diversion where Northglenn could utilize the water for aug-
mentation.
Thornton Enclave
As shown in Table 4-2 (reproduction of Table 3-1 for convenience),
Northglenn expects to receive 885 acre-feet of wastewater from an enclave
of Thornton which will be used as replacement water to FRICO by Northglenn.
Northglenn's opinion is this flow does not require augmentation.
Whether or not augmentation water is reauired will be settled in the
Water Court. Also, if there is less water available than the estimated
885 acre-feet, additional replacement water will be required which can
be provided by increasing the diversion from Grange Hall Creek or the
tributary well field.
The effect of requiring additional augmentation of the 885 acre-feet
will be to require more surface water rights. The total diversions to be
augmented in Table 4-2 would be increased by 885 acre-feet per year.
Grange Hall Creek
Grange Hall Creek is the most convenient and economical source of
replacement water but is subject to water being physically available in
the stream. Studies by Northglenn show the entire low flow of the
stream may be diverted for Northglenn's use. Only during runoff from
snowmelt or storm events greater than Northglenn's ability to divert
will water flow down the stream. Except for runoff periods, Northglenn
will have the capability of drying up Grange Hall Creek.
While Grange Hall Creek is a small intermittent stream, there are
some existing water rights along the creek which are senior to Northglenn
and must be protected. These rights are owned by one person and total
10.6 cfs. Northglenn intends to augment these rights when legally
required to do so by releasing water into Grange Hall Creek from the
Lower Clear Creek Ditch, or by releasing Grange Hall Creek drainage
runoff to meet the demand of the lower water right users (15).
Legal Issues
In analyzing the water rights and augmentation plans of the
Northglenn project, several legal issues were identified. These will
be resolved through the Water Court process if necessary and the
resolutions could have a significant effect on implementation of
Northglenn's Water Management Plan if decisions were adverse to Northglenn.
59
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TABLE 4-2
NORTHGLENN'S WATER BUDGET
1988 Conditions
CONDITION
Treated Water Requirements
Household and Commercial
Irrigation (lawns and parks)
Option 1
Without
Deen Wells
Dry Avg
4140 4140
3200 2700
Option 2
650 af
Deeo Wells
Dry Avg
4140 4140
3200 2700
Option 3
2300 af
Deep Wells
Dry Avg
4140 4140
3200 2700
Option 4
Return to
Metro
Dry Avg
4140 4140
3200 2700
Total Water Required 7340
Raw Water Sources
Farmers Highline 69
Standley Lake Shares 1074
Church Ditch 135
Berthoud Pass Ditch 120
Arapahoe Well No. 7 5
Proposed Deep Wells 0
FRICO Owned Water 5937
Total Water Supplies 7340
FRICO Exchange
Net Amount Rec'd from FRICO 5937
10Z Bonus (500 AF min) 594
Reservoir Evaporation 316
Total Payback Requirement
6847
Replacement/Wastewater Return
Sewage - Northglenn 4016
Sewage - Thornton Enclave*- 885
Sewer Line Infiltration 300
Storm Runoff-Grange Hall Crk 1200
Tributary well Field 446
Total Water Available 6847
Excess Physical Supply
(Total Available - Payback
Requirement) 0
6840
137
1504
389
608
5
0
4197
6840
4197
500
236
4933
4016
885
300
0
0
5201
268
7340
69
1074
135
120
5
645
5292
7340
5292
529
316
6137
4016
885
300
936
_0
613?
6840
137
1504
389
608
5
645
3552
6840
3552
500
236
4288
4016
885
300
0
_0
5201
913
7340
69
1074
135
120
5
2295
3642
7340
3642
500
316
4458
4016
885
300
0
0
5201
743
6840
137
1504
389
608
5
2295
1902
6840
1902
500
236
263g
4016
885
300
0
0
5201
2563
7340 6840
69 137
1074 1504
135 389
120 608
5 5
0 0
5937(3) 4197(3)
7340
4016
885
300
0
0
5201
6840
4016
885
300
0
0
5201
To Metro Sewer
for Treatment and
release to South
Flatte River
Diversions to be Augmented
Grange Hall Creek 1200 0 936 0 0
Tributary Well Field 446 0 0 0 0
0 To Metro Sewer
0 for treatment and
release to South
Platte River
Total Augmentation Require-
ments 1646
Augmentation Rights Available 1985
339
Excess Water Rights to Meet
Flow Requirements
0
2136
2136
936
1985
1049
2136
2136
1985
1985
2136
2136
(1) An enclave of Thornton will be connected to'the Northglenn system.
(2) Excess water available in the system without augmenting which can be used for
irrigation of Northglenn owned FRICO land.
(3) Water obtained from FRICO by purchase or condemnation of additional shares.
60
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Listed below is a summary of some of the important issues
identified during this analysis:
a. The plan includes successive use of water for both municipal
and agricultural purposes. This includes FRICO water owned
by Northglenn as well as water borrowed from FRICO. The
legal question is whether this successive use is allowed.
b. Northglenn has claimed 100 percent depletion credit for
water stored in Standley Lake. Historically, there has been
a certain amount of return flow from agricultural use of
this water. The legal question is whether or not any down-
stream appropriators have a right to return flow from this
irrigation use.
c. Northglenn has claimed a total of 300 acre-feet per year
of infiltration into the sewer system as part of the waste-
water replacement credit. The basis for this is its con-
tention that the source water is Standley Lake stored water
and can be 100 percent consumptively used. It could be argued
that some of the infiltration is storm water. Further it is
questionable whether Northglenn has retained dominion and
control over this water.
d. Standley Lake and the Croke Canal are decreed for irrigation
and domestic purposes. The legal question is whether or
not a change of water rights to municipal purposes must be
included in the plan.
e. Another legal issue is whether or not a shareholder is
entitled to water of a quality suitable for a use other
than that for which the water has been historically used.
This issue involves cities that desire, in the future, to
use the Bull Canal system for domestic water supply.
f. Lining of the Bull Canal system will reduce the amount of
seepage to the groundwater and may adversely affect irri-
gators who depend on such seepage. The legal question is
whether these irrigators have a vested right to the water.
The above legal questions will be resolved through the judicial
process if necessary. It is noted however, that resolution of all of
the legal questions will not necessarily insure that all adverse impacts
will be mitigated. For example, even though FRICO may legally be able
to line the Bull Canal, this action could adversely impact downstream
users that have historically depended on seepage water from the canal.
Summary of Legal Issues
EPA concludes that the Northglenn water rights applications, including
change of water rights, and the augmentation plan are a logical approach to
preventing injury to other vested water rights. Although there are a number of
legal issues to be resolved and some changes to the water management plan
61
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as filed are likely, approval by the Water Court of a water supply plan
for the City is likely. The probable effect of any subsequent changes
to the plan during the court process will be to require more water to
augment these changes in flow.
EPA concludes, based upon expert opinion, that 1) other complex
plans with similar principles have been approved by the Water Court and
this plan can be administered by the State Engineer; 2) the amount of
water obtained from surface sources is reasonable based on historic
ditch diversions and stream depletions; 3) the exchange plan will suffic-
iently protect FRICO shareholders; 4) through the Water Court process,
out-of-priority diversions will be properly augmented; 5) the water rights
to be used for augmentation are sufficiently senior for that purpose;
6) South Platte water users will be compensated for additional ditch losses.
Agricultural Productivity
The four water supply options of the Northglenn Water Management
Plan are analyzed. Water supply alternatives which would develop West
Slope water resources have not been quantitatively analyzed. Such sources
do not affect East Slope agriculture detrimentally. Indeed, they may
have some small benefit due to supplying new return flow water to the
South Platte River.
The four options evaluated consist of three associated with imple-
mentation of the Northglenn proposal and an option to condemn or purchase
the required amount of water from FRICO. Option 3, which is the exchange
with FRICO using deep, nontributary well water is used as the baseline to
which other options and agricultural impacts of alternative water supplies
are compared.
A key issue in evaluating the proposed project is to determine its
potential impact on agricultural productivity. The primary objective
of this analysis is to quantify the agricultural impacts which would
accompany implementation of the Northglenn Water Management Plan, and
to compare them to the agricultural impacts which would result if
Northglenn purchased or condemned sufficient FRICO shares to meet its
raw water requirements. In 1979 the FRICO productivity was $342 per acre-
foot of consumptive use. The corresponding South Platte productivity was
$259 per acre-foot. (Figures used in the determination of impacts on
agricultural productivity under the four options are summarized in the
following sections. A more detailed presentation showing the derivation
of these values is included in Appendix G.)
Water Availability to_ _FRICO
The amount of water available to the FRICO farmers is dependent on
the option chosen. The estimated farm headgate delivery for each of the
options is summarized in Table 4-3. The values are based on the schematic
diagrams, Figures 3-1 through 3-4 (oversized, back of report) and Table 4-2,
The analyses ignore any benefit due to lining of the Bull Canal and
assume that the farm headgate deliveries are equal to 60 percent of the
sum of the releases from Standley Lake and the FRICO exchange return.
62
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(1)
(2)
TABLE 4-3
ESTIMATED FRICO FARM
HEADGATE WATER DELIVERIES
(1)
Option Description
1 Without deep wells
2 650 acre-feet from non-
tributary wells
3 2300 acre-feet from non-
tributary wells
4 Water from Standley Lake
Wastewater to Metro
Water (Acre Feet)
Average Year Dry Year
6390Z
63902
63902
3572
4706
4667
46502
788
Equal to 60% of sum of FRICO exchange return and release from
Standley Lake (see Figures 3-1 through 3-4).
Under these conditions there is also excess water over repayment
requirement available to irrigate Northglenn owned lands.
Augmentation Water
The required augmentation water from surface sources for the
four options evaluated is summarized in Table 4-4. Some of the
augmentation water will come from lands currently out of agricultural
production and some will come from lands currently in production. To
determine the impact of each option on agriculture, only that water
to be taken from lands currently in production is of consequence.
63
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TABLE 4-4
SURFACE WATER AUGMENTATION
Option Description
Total Required
(acre-feet)
Water Removed From
Currently Productive
Agricultural Land
(acre feet of
consumptive use)
Avg. Year Dry Year Avg.
1 Without deep wells 0
2 650 acre-feet from 0
nontributary wells
3 2300 acre-feet from 0
nontributary wells
4 Water from Standley Lake 0
Wastewater to Metro
1646
936
0
0
1667
888
0
0
Dry
1520
810
0
0
It is Northglenn's intention to remove the same amount of land from
agricultural production in an average year as would be necessary
in a dry year. The average year consumptive use associated with
that land is indicated above (2039.2/1859.3 x dry year consumptive
use.) This excess water would be available for irrigation of
Northglenn owned land. The 2039.2 and 1859.3 are the average and
dr.y year consumptive use values, in acre-feet, attributable to
the South Platte land which is currently in irrigated agricultural
production - Source: Wright Water Engineers, Inc.
^ ' Figures obtained by subtracting consumptive use of currently out-
of-production land (126 acre-feet) from total required.
64
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TABLE 4-5
GROSS PRODUCTIVITY OF FRICO AND SOUTH FLATTE
IRRIGATED LANDS AFFECTED BY THE NORTHGLENN PROJECT
Option Description
I Without deep wells
2 650 acre-feet from non-
tributary wells
3 2300 acre-feet from non-
tributary wells
4 Water from Standley Lake
Wastewater to Metro
(IN MILLION DOLLARS),
FRICO1
Average Year Dry Year Average Year Dry Year
SOUTH PLATTED
1.95
1.95
1.95
1.49
1.76
1.75
1.74
1.04
0.16
0.33
0.53
0.53
0.15
0.31
0.48
0.48
TOTAL GROSS
PRODUCTIVITY
Average Year Dry Year
2.11 1.91
2.28
2.48
2.02
2.06
2.22
1.52
Based on $342/acre-foot of consumptive use of irrigation water. FRICO deliveries given in Table 4;
irrigation efficiency = 65% in average year and 70% in dry year.
2 Based on $259/acre-foot of consumptive use of irrigation water.
Note: All lands which are removed from irrigated agricultural production are assumed to have a dry-farming
productivity of $60/acre.
Sample Calculation - Option 1, Average Year:
FRICO
Farm Headgate Delivery = 6390 A-F
Productivity of Irrigated Land = (6390)(.65)(342)=$!.42 M.
Irrigated acreage = 6390/1.04 = 6144 A.
Non-irrigated acreage = 15,000 - 6144 - 8856 A.
Productivity of Non-irrigated Land = (8856)(60)=$0.53 M.
Total FRICO Productivity = $1.95 M.
SOUTH PLATTE
Productivity of Irrigated Land = (2039.2-1667)(259)=$0.096M.
Non-irrigated acreage=(1667/2039.2)(1343.4) = 1098'A.
Productivity of Non-irrigated Land = (1098)(60)=$0.067 M.
Total South Platte Productivity = $0.16 M.
TOTAL GROSS PRODUCTIVITY = 1.95 + 0.16 = $2.11 M.
-------
Agricultural Productivity Under the Northglenn Plan
The individual and combined gross agricultural productivities for
FRICO and South Platte lands under each of the four options considered
are presented in Table 4-5. Anticipated productivities of the irrigated
FRICO lands were computed using the farm headgate deliveries indicated
in Table 4-3, assumed irrigation efficiencies of 65 percent in an average
year and 70 percent in a dry year, and an estimated production value of
$342 per acre-foot of consumptive use of irrigation water. It was
assumed that water delivered to FRICO pursuant to the "bonus" provision
of the exchange agreement would be used to bring additional land under
irrigation. The productivities in Table 4-5 for Options 1 through 4
represent the sum of the productivities of irrigated and nonirrigated
land in the FRICO and South Platte lands of concern. It should be noted
that additional water is available under Options 1 through 3 in an average
year and Option 3 in a dry year for possible irrigation of Northglenn
owned lands. The basic calculations for agricultural productivity are
presented in Table 4-5. Further explanation of the calculations is
presented in Appendix G.
The analysis above uses an "average benefit" approach to analyzing
the impacts of the Northglenn Water Management Program on agricultural
productivity in the study area. It is agreed that a marginal benefit
approach to productivity analysis would, in theory, be technically more
correct. Such an approach recognizes that additional output (crop value)
is not constant, but varies with the addition of incremental units of
input (acre-feet of consumptive use of water). After careful consideration
of the various theoretical and practical aspects of making this productivity
analysis, however, EPA has concluded that use of average productivity
parameters is adequate under these circumstances.
Option 4 does not include consideration of any increased productivity
along the South Platte due to the additional water that would be discharged
to the River via the Denver Metro Plant (433 acre-feet per month). This
additional water is less than three percent of the flow in the South Platte
below the Metro Plant. It is unlikely "that this flow would result in any
measurable increase in agricultural productivity in the study area,
particularly in view of the fact that the South Platte ditches under
consideration generally receive an adequate water supply. If the water
was available to the South Platte ditches of concern it could be assumed
to be available for the six months of the growing season. The maximum
increased productivity along the South Platte for this additional water,
based on $259 per acre-foot of consumptive use, would be $673,000 per year.
Any increases in agricultural productivity beyond the confines of the
study area were neglected.
As can be seen in Table 4-5, the option that contemplates maximum use
of nontributary groundwater (Option 3) results in the greatest agricultural
productivity (least impact). Option 4, which contemplates Northglenn's
acquiring its entire water supply from FRICO by purchase or condemnation
with wastewater discharged to the South Platte, results in the lowest
agricultural productivity (greatest impact). Bar charts presented in
Figure 4-3 graphically illustrate the gross productivities under the four
options in both an average and dry year.
66
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FIGURE 4-3
o 2.0
o
I
E '-°
>
K
O
Q
O
cc
a.
a:
>- i.o
Q
O
CC
O.
2.11
1.91
AVERAGE YEAR
2.48
2.28
2 3
OPTIONS
DRY YEAR
2.22
2.06
2.02
.52
234
OPTIONS
GROSS AGRICULTURAL PRODUCTIVITY
-------
EPA concludes from this analysis that under the exchange program positive
agricultural benefits are obtained if all the augmentation water is derived
from deep wells (Option 3). If Northglenn implements an exchange which
requires augmentation water entirely from other irrigators (Option 1), there
will be some loss to agriculture, but productivity will be higher than if
Northglenn did not execute an exchange agreement (Option 4). EPA therefore
concludes that compared to the situation wherein litigation would have been
successful, the proposed exchange, regardless of the source from which
Northglenn obtains augmentation water, has significantly less economic im-
pact on agriculture.
The long term exchange arrangement with FRICO enhances the likelihood
that significant acreage of irrigated land will remain productive farmland
during this century. EPA has determined that this plan meets EPA's policy
to protect environmentally significant agricultural land.
WATER QUALITY
Water Supply
Options 1, 2 and 3 include a discharge into the Bull Canal. This
effluent will degrade the existing water quality of the Bull Canal and
in certain dry year conditions water below the discharge point will
consist of 100 percent effluent. Potential health risks are in areas where
public contact and exposure with the wastewater, particularly 100 percent
effluent, are likely to occur. Potential health risks are also identified
with using the wastewater for irrigation of vegetable gardens on farms and
raw edible food crops grown for public sale and consumption.
Although it is not clear based on limited data whether the Bull
Canal is currently suitable for use as a domestic water supply, future
water quality of the Bull Canal below the discharge will be unsuitable
as a water supply source primarily because nitrate concentrations will
range between 12 mg/1 and 20 mg/1.
The State of Colorado defines raw waters suitable for potable water
supplies as follows: (16)
"These are waters which, after receiving approved disinfection
such as simple chlorination or its equivalent or which after
receiving standard treatment (defined as coagulation,
flocculation, sedimentation, filtration, and disinfection
with chlorine or its equivalent) will meet Colorado drinking
water regulations and any revisions, amendments, or supple-
ments thereto."
Standard water treatment as defined above will not effectively remove
nitrate.
68
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Annexation requirements of Frederick, Colorado require that lands
brought into the town must provide sufficient water supplies for the
annexed land. Landowners surrounding Frederick generally own shares in
FRICO water delivered by the Bull Canal. Implementation of a plan which
discharges effluent to the Bull Canal would render these waters unacceptable
as a water supply for Frederick. The current use of the Canal is solely
for agricultural use. Thus it is EPA's conclusion that the protection
of these waters for a potential future water supply source is unnecessary
and EPA recommends that Frederick explore other options to satisfy future
water supply demands.
Fort Lupton is currently using a shallow well field along the
South Platte River for their water supply source. However, this source
has high nitrates. Sand Hill Lake is an option the Town is considering
as a water supply source. Sand Hill Lake is filled by the Coal Ridge
Ditch. Concern has been expressed that Bull Canal water will reach the
Coal Ridge Ditch by way of the containment pond at the terminus of the
Bull Canal. Fort Lupton is primarily concerned that nitrates in the
Bull Canal resulting from Northglenn's plan will reach the Coal Ridge
Ditch and render Sand Hill Lake unuseable as a water supply.
Nitrate concentrations in Coal Ridge Ditch are between 0.9 mg/1 and
1.3 mg/1 which is well below the water supply criterion of 10.0 mg/1.
Sand Hill has a nitrate concentration of 5.5 mg/1 probably due to agri-
cultural runoff. The projected Bull Canal nitrate concentration in an
average year ranges from 12 mg/1 to 14 mg/1, depending upon the option.
Operation of the Bull Canal is intended to make optimum use of the
irrigation water available. FRICO therefore does not deliver water with
the intention of having it reach the containment pond since that water is
lost. However, during occasional storm events and flushing of the Bull
Canal, water does reach the pond and may be released to the Coal Ridge
Ditch. This reservoir normally receives not more than 6 acre-feet of
water in any one year (4).
The operational flexibility of the Northglenn Bull Canal reservoir
should adequately control effluent mixed water entering Coal Ridge Ditch
by way of the containment pond. However, tailwater from lands irrigated
below the reservoir discharge point may enter Coal Ridge ditch and then
Sand Hill Lake. Data to calculate the increased nitrate concentration
in Sand Hill Lake are currently not available. EPA concludes that the
Bull Canal will not significantly contribute water to Sand Hill Lake and
therefore will not contribute to higher nitrate concentrations there.
Irrigation Water Quality
The projected total nitrogen concentrations in the Bull Canal at the
point of wastewater discharge are presented in Table 4-6 . As a worst
case condition in a dry year the canal below the discharge will consist
of 100 percent effluent.
69
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Sugar beets and barley are the nitrogen sensitive crops grown with
Bull Canal water. The optimum nitrogen uptake of sugar beets is 81 pounds
per acre per year (Ib/ac/yr), and for barley it is 75 Ib/ac/yr. The total
nitrogen delivered is presented in Table 4-7 for the three options.
TABLE 4-6
TOTAL NITROGEN CONCENTRATION IN BULL CANAL
Average
Option Effluent Concentration Year Concentration
1 15-20 mg/1 8.8-11.5 mg/1
2 15-20 mg/1 7.9-10.5 mg/1
3 15-20 mg/1 6.6-8.6 mg/1
TABLE 4-7
TOTAL NITROGEN DELIVERY TO SUGAR BEETS AND BARLEY
Total Nitrogen Delivery
(Ib/ac/yr)
Dry Year Average Year
Option Sugar Beets Barley Sugar Beets Barley
1 42-56 42-56 25-32 14-18
2 42-56 42-56 22-29 12-17
3 42-56 42-56 18-24 10-14
The projected nitrogen concentrations in Northglenn's effluent
should not exceed the recommended application rates for either sugar
beets or barley. Concentrations will approach the optimum nitrogen up-
take of sugar beets and barley in a dry year if effluent nitrogen concen-
trations reach 29 mg/1 and 48 mg/1, respectively. At these
concentrations, which are higher than-expected, all the crop nitrogen
demand could be provided by the effluent.
While total nitrogen concentrations are not expected to cause
problems in either sugar beet or barley production, management of water
applications to sugar beets will be necessary to satisfy Great Western's
contractual agreements of no nitrogen after July 15 of each year.
70
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TABLE 4-3
GUIDE TO THE USE OF SALINE WATERS FOR LIVESTOCK AND POULTRY
Total Soluble Salts
Content of Waters( mg/1)
Less than 1 000 mg/1
(EC < 1.5)
Relatively low level of salinity.
livestock and poultry.
Excellent for all classes of
1 000-3 000 mg/1
(EC = 1.5 - 5)
Very satisfactory for all classes of livestock and poultry. May cause
temporary and mild diarrhea in livestock not accustomed to them or watery
droppings in poultry.
3 000 - 5 000 mg/1
(EC - 5 - 8)
Satisfactory for livestock, but may cause temporary diarrhea or be refused at
first by animals not accustomed to them. Poor waters for poultry, often causing
water feces, increased mortality and decreased growth, especially in turkeys.
5 000 - 7 000 mg/1
(EC = 8-11)
Can be used with reasonable safety for dairy and beef cattle, for sheep, swine
and horses. Avoid use for pregnant or lactating animals. Not acceptable for
poultry.
7 000 - 10 000 mg/1
(EC = 11 - 16)
Unfit for poultry and probably for swine. Considerable risk in using for
pregnant or lactating cows, hqrses, or sheep, or for the young of these species,
In general, use should be avoided although older ruminants, horses, poultry,
and swine may subsist on them under certain conditions.
Over 10 000 mg/1
(EC > 16)
Risks with these highly saline waters are so great that they cannot be
recommended for use under any condition.
Source; Environmental Studies Board, Nat. Acad. of Sci.,Nat. Acad. of Eng .
Water Quality Criteria 1972
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TABLE 4-9
RECOMMENDATIONS FOR LEVELS OF TOXIC SUBSTANCES IN DRINKING
WATER FOR LIVESTOCK
Constituent
Aluminum (al)
Arsenic (As)
Beryllium (Be)
Boron (B)
Cadmium (Cd)
Chromium (Cr)
Cobalt (Co)
Copper (Cu)
Fluoride (F)
Iron (Fe)
Lead (Pb)a
Manganese (Mn)
Mercury (Hg)
Molybdenum (Mo)
Nitrate + Nitrite
(N03-N+N02-N)
Nitrite (NO -N)
Selenium (Se)
Vanadium (V)
Zinc (Zn)
Total Dissolved Solids (IDS)
5 mg/1
0.2 mg/1
No data
5.0 mg/1
.05 mg/1
1.0 mg/1
1.0 mg/1
0.5 mg/1
2.0 mg/1
No data
0.1 mg/1
No data
.01 mg/1
No data
100 mg/1
10 mg/1
0.05 mg/1
0.10 mg/1
24 mg/1
10,000 mg/1
Lead is accumulative and problems may begin at threshold value =
0.05 mg/1
Source: Environmental Studies Board
"Water Quality Criteria 1972"
National Academy of Science, National Academy of Engineers.
72
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Water Quality Effects on Livestock
There is little quantitative information available concerning the
tolerances of livestock to various water quality parameters. The per-
missible concentration of various substances in water depends, to some
extent, on the daily water consumption of the animal. It appears that
animals can tolerate higher salinities than humans, and it is conceivable
that they differ in their tolerances of specific elements (17). Waters
with high concentrations of nutrients (nitrogen and phosphorus) consumed
by livestock can cause physiological disturbances such as gastrointestinal
symptoms, wasting disease and death. Among the functions of animals,
lactation and reproduction are generally the first to be disturbed by
continuous use of water with high nutrient concentrations. Adverse
effects of high salinity waters on livestock are due to the osmotic pressure
of the total salts present rather than the toxic effect of any one con-
stituent (17). In addition to the effects of the total salt concentration,
some salts are specifically toxic to animals, at certain concentrations.
Among the compounds of concern in water are nitrates, fluorides, and the
salts of selenium and molybdenum. Tables 4-8 and 4-9 provide a set of
recommendations for maximum levels of various elements in drinking water
supplies to livestock. The Northglenn effluent quality is expected to
remain within these recommended limits, thus posing no threats to livestock.
Neither is it expected that drinking reclaimed water would make animal
tissues unwholesome for human consumption.
Concern over the issue of nitritis (toxicity to cattle caused by
high nitrite concentrations in silage) has been expressed. This situation
occurs when nitrate is taken up by corn in high concentrations. When the
corn is stored as silage and anaerobic conditions occur, the biological
activity that occurs converts nitrate to nitrite which can be toxic.
Nitrate applications to corn will not be excessive under the plan
provided application of chemical fertilizers is reduced to compensate
for nitrates in the wastewater. This problem can further be mitigated
by maintaining aerobic conditions in stored silage. EPA concludes that
this will not be a problem with corn silage grown under the FRICO system
using Northglenn's effluent for irrigation water.
Groundwater Pollution from Lagoon/Reservoir Seepage
Subsurface investigations (18, 19) have been performed at the
treatment plant and storage site. Exploratory borings indicate that
the overburden soils and bedrock vary with respect to depth and
classification. The bedrock is predominantly claystone with some
claystone-siltstone deposits.
Water pressure tests were conducted to evaluate the permeability
of the subsurface formations. The results indicate that the silt-
stone is relatively impervious with variable coefficients of permea-
bility (1 to 60 feet/year). Higher permeabilities were detected at
the interface of the claystone and sandstone lenses with a maximum
value of 2400 ft/yr and a general range of 60 to 530 ft/yr. Claystone
permeabilities are erratic and vary from 20 to 1000 ft/yr. The claystone
becomes less permeable with depth.
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Undisturbed samples collected at the storage reservoir site were
tested and found to have a coefficient of permeability less than 1 ft/yr.
This tends to indicate that leakage occurs in joints and fractures within
the claystone.
Exploratory borings show an erratic free water level. Depths as
shallow as 7 feet exist in the northwest portion of the site. This
water is believed to be perched water caused from seepage from the
adjacent Bull Canal. Other boring locations indicate water depths of
11 to 28 feet.
Although the permeabilities are generally low, there is a possibility
for rapid movement through joints, fractures, and bedrock interfaces.
An inactive fault trace may underlie the northwest corner of the proposed
reservoir. Water movements along such fractures must be reduced to
prevent groundwater contamination by the overlying wastewater and treated
effluent. To satisfy this requirement the proposed Northglenn treatment
facility and storage reservoir will be lined with random clay fill material
from the excavation site. The design requires scarifying the reservoir
and lagoon bottom soils to a depth of at least six inches and recompacting
the soil to a 95 percent density. Northglenn states that if granular soils
or fractured materials are encountered in the reservoir bottom, they will
be covered with two feet of selected, compacted impervious fill material.
EPA will require as an alternative to this that Northglenn consider moving
the entire dike south to exclude such a fault trace if present. Resolution
of the problem will be done following removal of overburden down to the
competent zone. (See special construction condition in Chapter 5.)
The estimated seepage of the lined reservoir after 95 percent com-
paction is estimated to be 0.5 feet per year. The proposed lagoon and
reservoir has an area of 110 acres. The anticipated total seepage volume
per year is 55 ac^e-feet. Based on a void ratio of 25 percent in the
soils below the reservoir, the radial movement of seepage is estimated to
be two feet per year.
During t! z subsurface investigation, many holes were drilled or
augered rlong the dam axis and throughout the area to be ponded, which
have created possible zones of permeability. These penetrations are from
10 feet deep to 66 feet deep.
A study by the USGS and State Engineer's office involved two deep
(1550 feet) monitoring wells within the impoundment area. These cased
holes will be abandoned and replaced by agreement between Northglenn,
the previous owner, and USGS. A third hole, 600 feet deep, was drilled by
the Chen Engineering and Associates under contract with Northglenn.
Each penetration below the pond elevation base of 5120 feet.needs to
be considered as a possible source of fluid loss. EPA has determined that
these penetrations will need to receive special attention before the com-
paction of the pond base or the dike construction.
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EPA will require that all shallow test holes within the reservoir
site that have a depth greater than 30 feet below the pond base must be
plugged with concrete. Any test holes that have a depth of less than
30 feet must be back filled and compacted. The cased USGS test wells
(BW-77-15B and BW-77-17B) must be pressure plugged with concrete from
the bottom up to insure proper abandonment. (A special construction
condition has been developed for this problem and is described in Chapter
5.)
In addition to the rate of movement, the concentrations of the
potential contaminants must be considered. Biological oxidation in the
aerated lagoon will reduce certain chemical constituents in magnitude
while others will be converted to another form. For instance, the
biochemical oxygen demand (BOD) will be reduced by at least 90 percent
and ammonia/ammonium will be oxidized to nitrite/nitrate.
Some chemical components of wastewater which remain after treatment
are potential groundwater pollutants. Most wastewater pollutants that
pass into the soil will be filtered out, adsorbed, or exchanged with
other ions within the soil matrix. Nitrates, soluble salts, and some
heavy metals however, readily move through the soil matrix and are of
particular concern as groundwater contaminants.
The clay liner in addition to EPA's special construction conditions
on handling of the fault trace and sealing of wells, should limit the
percolation of wastewater to an acceptable and practical volume as designed.
Monitoring wells are proposed for the vicinity of the treatment plant
and storage reservoir site. Periodic chemical analysis will indicate any
seepage effects on groundwater quality.
WATER RESOURCES
Lining of Bull Canal
Pursuant to the four-way agreement between FRICO, Northglenn,
Thornton and Westminster, the City of Thornton is to pay FRICO to line
the Bull Canal system and laterals (20). The purpose of the lining is
to reduce seepage losses and improve farm headgate yield.
Seepage measurements of the Bull Canal system and Big Dry Creek
below Standley Lake were made jointly by Wright Water Engineers, con-
sultants for Northglenn, and Hydro-Triad Engineers, consultants for FRICO
(21). No final report has been prepared, but interim results were made
available for review. The extent of lining is yet to be determined.
In certain areas groundwater may be flowing into the Bull Canal and
lining these portions would be detrimental.
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Historically, approximately 60 percent of the Standley Lake water
released in the Standley system (22) has been delivered to the farmers.
Data presented by Wright Water Engineers indicate that present seepage
losses in Big Dry Creek between the outlet of Standley Lake and the Bull
Canal headgate are between 3 and 5 percent. In the future, as the area
urbanizes, it is expected losses in Big Dry Creek will reduce to zero
or even show a gain. By lining the canal system, a future total system
loss of 10 percent is estimated (23).
Reduction of seepage losses may lower groundwater levels and affect
wells adjacent to the canal. Also, according to a study by Colorado
State University for the Colorado Department of Natural Resources, improve-
ment of irrigation efficiencies by lining may have an overall negative
effect on water availability to agriculture in the South Platte Basin (24).
Groundwater Under Lands Taken Out of Production
Certain lands historically used for agriculture will, under the
Northglenn plan, be taken out of production. The water rights associated
with these lands will be used for augmentation by Northglenn. Removal
of irrigation from land decreases the groundwater recharge. The effect
of this reduction by Northglenn's plan has been estimated to be very small
and will not have a noticeable impact. For example, an analysis of one
parcel along the Sout;h Platte indicated an estimated groundwater level
lowering of less than three inches as a result of removal of irrigation
water. Continued removal of land from agricultural production for
urbanization in the long term will have a more significant effect on
groundwater levels.
TAXES AND LAND VALUE
Changes in Tax Revenue
Northglenn has purchased approximately 1840 acres of land in Weld
County and 49 acres of land in Adams County in order to obtain water
rights for the water resource management plan. This results in a net
loss in taxes to both counties because municipalities are tax exempt.
The loss of these irrigated lands from the tax rolls of Weld County
and Adams County will result in a loss in tax revenues of $8,000-8,500
and $180-300, respectively.
The values are considerably less than the preliminary tax losses
presented at the Northglenn Panel Meeting on September 13, 1979. The
values presented at the Panel Meeting are not tax losses but represent
the assessed valuation of Northglenn-owned land in Weld County.
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Effect on Land Values Adjacent to Treatment Site
To evaluate the effects of a sewage lagoon on land values in an
agricultural area, three realtors from Louisville, Colorado, and a land
assessor from Boulder, Colorado were contacted (25). Louisville and
Boulder were selected because the rural-residential-agricultural nature
of land surrounding their wastewater treatment plants has similarities
to the proposed Northglenn plant location. Louisville has a lagoon
within one-half mile of the community and Boulder has a mechanical plant
near its eastern edge.
Two of the three realtors in Louisville were not aware of the presence
of the lagoon adjacent to their community. It has been EPA's experience
that unless a lagoon is controversial and a public stigma is attached to
the facility and the land around it, there is no real reason for land
values to decline because of construction of the facility. Suburban
residences immediately downwind of the Boulder facility are still in
demand and it is estimated that prices there are depressed no more than
five percent. The value of agricultural land around the Louisville lagoon
has not decreased in value. Good farmland is in such demand that proximity
to the lagoon is not a factor.
It is concluded that the effect of the Northglenn facility on sur-
rounding land and residential values will be minimal if the treatment system
and reservoir operate correctly. A decrease of up to five percent of res-
idential value may occur but farmland and values should not be affected.
PUBLIC SAFETY
Reservoir Safety and Stability
The reservoir embankment stability analysis is based on two reports
provided by Northglenn (18, 19). Review of these reports concludes that
the subsurface and geological investigations for the proposed reservoir
site have been adequate.
Earthquake Analysis
In the Earthquake Susceptibility Evaluation the Denver Seismic
Zone is noted as the feature most likely to have a seismic effect on the
Northglenn reservoir area. On page 15 it states that "it is unlikely
that future earthquakes (in the Denver Seismic Zone) would exceed
magnitudes greater than 5.5 to 6.0 (on the Richter Scale)" (19). This
77
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infers that a maximum design earthquake of magnitude 6.0 should be con-
sidered. On page 17 is stated "selected a pseudo static seismic
coefficient of 0.05 g for the operational base earthquake and 0.10 g
for the maximum design earthquake". The pseudo static seismic
coefficient of 0.10 g was used in the stability analysis of the
reservoir (26). For the Denver Seismic Zone an operational base
criteria of 0.05 g, pseudo static seismic coefficient for an earth-
quake magnitude of 5.3, and 0.10 g for a maximum design earthquake
of 6.1 Richter magnitude are reasonable based on U. S. Army Corps of
Engineer criteria.
Embankment Stability Analysis
The stability analysis methods used are the most commonly used for
this type of analysis. A detailed review of the adequacy of the analysis
is beyond the scope of this review. However, safety factors arrived at in
the analysis appear to be based on accepted criteria (27).
Seepage
The influence of underseepage and the resulting pore water pressures
on the stability of the embankment are significant factors in the dam
stability analyses. Pore water pressures should be monitored as indicated.
However, this can be better accomplished by installing piezometers instead
of observation wells, because the observation well will at best show a
composite flow water surface. The results of the water pressure testing
were correctly analyzed as primarily the result of secondary permeability.
Embankment Construction
The material to be excavated from the reservoir area appears adequate
for the embankment construction. Recommended construction practices are
along the lines•of the Bureau of Reclamation Standards (28).
Northglenn's engineers call for a four foot freeboard with 18 inches of
riprap on the reservoir face of the embankment. The freeboard of four
feet was'determined on the basis of an effective fetch of 2,355 feet and
a design wind velocity of 63 miles per hour. Northglenn's engineers have
considered wave run-up in the determination of freeboard.
An impervious asphalt liner will be placed along the inside face of
the embankment from top to bottom to prevent wave action damage to the
embankment. The asphalt liner will consist of a 3^5 inch layer of hydraulic
asphalt concrete, a 1% inch thick binder course and a 5-inch drain course.
Based on the analysis described by Mostertman (29) it would appear that
with the use of an asphalt liner the wave run-up would result in a required
freeboard in excess of 6 feet. Calculations for a riprap facing indicate
that 50 percent of the stone used should have a diameter of 15 inches or
greater rather than the 12 inches mentioned in the report.
Discussions with Northglenn's engineers indicate they have given
consideration to potential embankment damages arising from ice formation
or the potential of damages from earthquake generated waves.
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Radiological Emergency
The U.S. Department of Energy operates, through a private contractor,
the Rocky Flats nuclear weapons manufacturing plant which is almost ten
miles west of Northglenn. There have been accidents at the plant whereby
radioactive materials have been released into the air. State and Federal
authorities have for some time been conducting investigations to determine
the magnitude and extent of a threat a future incident may pose, and develop
plans and policies to minimize effects.
The City of Northglenn is located just beyond the area known as the
Category II area (10 miles radius) of the Rocky Flats Plant. The proposed
water supply system, however, includes Standley Lake and Woman Creek
which are inside the category I area (5 mile radius). Accordingly, EPA
has determined Northglenn must comply with the provisions of the proposed
Radiological Emergency Response Plan for Rocky Flats.
State officials have been waiting for several months to distribute
this pamphlet telling those who live within 10 miles of the Rocky Flats
nuclear weapons plant what to do in case of an emergency there. Its
distribution, however, has been stalled by two obstacles. First, state
and federal officials can't agree on what might be the worst case accident
that could happen at the plant, or what precautions should be taken. Second,
a test of the state's Disaster Emergency Services Agency revealed that the
state would find it difficult to carry out the emergency response outlined
in the plan. The current draft is now in the Governor's office while
officials attempt to improve the state's emergency response plan.
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AIR QUALITY
There are two air quality issues of concern. The first concern is
the indirect adverse impact of project accommodated population growth
on the region's air quality. The second concern is the potential
direct impacts caused by odors from the treatment facilities.
Growth~Related Impacts
The funding of wastewater treatment and collection facilities that
involve the addition of capacity to serve future population growth should
be done in a manner encouraging the implementation of measures to reduce
the existing air pollution problem. Population growth will occur in the
Denver metropolitan area. Unless strategies to reduce air pollution
(principally from automobiles) are implemented, air quality will not
significantly improve. Funding of additional wastewater facilities does
not cause air pollution, but it does support growth, both economically
and locationally, by providing readily available services for sewage
treatment and reducing development costs. Therefore, EPA believes that
funds should be made available only where reasonable actions are being
taken to deal with the air quality impacts of growth. (See Final Action
for the Denver Overview EIS, the Colorado State Air Quality Implementation
Plan, and Section 176(C) of the Clean Air Act.)
Accordingly, EFA requires:
1. A commitment from the elected officials of the local
governments which are to be served by the proposed
wastewater treatment facility to:
a. Implement air pollution control measures considered
reasonable for their area from the general list
of measures outlined in Appendix C of the
Final Action on the Denver Regional EIS for
Wastewater Facilities and the Clean Water Program.
b. Participate in the process established by the State
of Colorado and the Denver Regional Council of
Governments to revise the Denver element of the
State Air Quality Implementation Plan.
c. Support the implementation of the Denver element
of the State Air Quality Implementation Plan as
approved by EPA.
2. Design wastewater facilities, based on DRCOG population
projections (or as revised during the State Air Quality
Implementation Process) with capacity increases staged
in accordance with the April 25, 1978 regulations.
3. The grant applicant (in conjunction with local jurisdictions)
must develop and implement a sewer tap program which determines
annually the number of taps available for new residential
development and is consistent with the DRCOG population
forecasts for 1980, 1990, and 2000.
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4. Development which will be served by the additional capacity
must be within the adopted regional urban service area boundaries
and contiguous to existing development as stated in DRCOG's
Regional Plan Policies. EPA requires evidence that local
governments within the service area are promoting contiguous
development through zoning actions, building permit approvals
and tap allocations.
Northglenn will meet these requirements by abiding by certain grant
conditions which are described in the Air Quality section of Chapter 5.
Potential Odor Problems
The Odor Emission Regulation of Colorado (30) prohibits emissions of
odorous air contaminants from any single source such as result in detect-
able odors which are measured in excess of the following limits:
For areas used predominantly for residential or commercial
purposes it is a violation if odors are detected after the
odorous air has been diluted with seven (7) or more volumes
of odor-free air.
In all other land use areas it is a violation if odors
are detected after the odorous air has been diluted
with fifteen (15) or more volumes of odor-free air.
The "worst case" for potential odor problems is to assume that the
aeration system is not operating or that an algal bloom has occurred, and
wind conditions do not allow for dispersion of the generated odor. Four
"worst case" meteorological conditions were examined to determine approxi-
mately how far odorous air could travel from the proposed Northglenn
treatment site before being diluted seven and fifteen times, respectively.
The four "worst case" conditions tested were for:
most unstable dispersion (Stability Class A)
neutral dispersion (Stability Class D)
stable dispersion (Stability Class E)
very stable dispersion (Stability Class F)
The height of the odorous air, assuming the aeration system is not
functional or a bloom has occurred, above the lagoons/reservoir is
estimated to be ten meters (33 feet). This is the minimum emission height
for an area source like lagoons. Accounting for this emission height,
wind speed, and downwind distances for effective vertical mixing, the
distances to seven and fifteen dilutions were calculated (31). The results
of this analysis are presented in Table 4-10 and illustrated in Figure 4-4.
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FIGURE 4-4
, 0.23
0.57
2.23
0.63
WORST CASE ODOR ANALYSIS
(using Class f wind stability - wind speed 3io 7 mph
and an inoperative aeration system)
LEGEND
» Buildings (Residential, Agricultural and Commercial)
Estimated area exceeding 15 dilutions
Estimated area exceeding 7 dilutions
Base: USGS.Weld County, Colorado 1978.
Ml LE
0.27
^Treatment Site '
0.41
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TABLE 4-10
ODOR ANALYSIS
Meteorological Distance to Distance to
Condition Seven Dilutions Fifteen Dilutions
Kilometers (Miles) Kilometers (Miles)
Unstable (Class A) 0.21 (0.13) 0.35 (0.22)
Neutral (Class D) 0.85 (0.53) 1.35 (0.84)
Stable (Class E) 1.27 (0.79) 2.37 (1.47)
Very Stable (Class F) 2.10 (1.30) 4.10 (2.55)
A very stabl'e atmosphere, evident of a strong, low-level temperature
inversion accompanied by low wind speed, is the "worst case" meteorological
condition for the dispersion of odorous air. Hourly wind data from
Stapleton International Airport show that Class E and Class F stabilities
occur 6.7 and 16.7 percent of the time, respectively, for wind speeds from
one to seven miles per hour (mph). The Class F category, for this analysis,
is the worst case condition. Under the Class F category (winds 1 to 7 mph)
the wind speed frequency is further separated into winds 1 to 3 mph and
3 to 7 mph. The wind speed frequency of 1 to 3 mph occurs less than half
of the time, while wind speed frequency between 3 to 7 occurs about 66
percent of the time. The wind speed frequency by direction at Stapleton
Airport is presented in Table 4-11. .The diurnal drainage flow in the South
Platte River Valley may be more evident with on-site meteorological data,
but data from Stapleton International Airport are considered representative
of long-term averages for this area.
Accounting for both the topography and diurnal air drainage flows
in the vicinity of the proposed site and canals, the most likely areas
affected by odorous air will be in a northeasterly to northwesterly
direction from potential odor-generating sites. The area within a radius
of 2.55 miles from the treatment site is calculated to be a maximum that
could be affected by odorous air prior to 15 dilutions under worst case
conditions. The maximum area for odorous air impact to achieve 7 dilutions
has a radius of 1.3 miles.
Potential odor sources at the proposed plant include: 1) raw waste-
water entering the plant; 2) dredging accumulated sludge from the aerated
lagoons; 3) odors emitted due to plant upset conditions; 4) decaying algal
blooms; and, 5) ultimate sludge disposal.
In the proposed facility raw wastewater enters through a closed
"force main" pipe to a covered concrete inlet structure. The wastewater
is then conveyed to the aerated lagoons through pipes that discharge below
the lagoon water surface. Based on analyses prepared by Northglenn's
engineer there will be a dissolved oxygen concentration greater than
2 mg/1 at the plant site and therefore no sulfide odors would be generated.
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TABLE 4-11
1960-1964 Hourlv Relative
Freauencv Wind
Data Summarized for F Stability from
Stapleton International Airport
Wind Wind Speed Frequency %
Direction (1-2 mph)
N*
NNE*
NE
ENE
E
ESE
SE
SSE
S
SSW
SW
WSW
W
WNW
NW
NNW*
0.25
0.21
0.19
0.24
0.26
0.29
0.37
0.31
0.89
0.98
0.47
0.32
0.18
0.13
0.29
0.18
, Denver, Colorado (2)
Wind Speed Frequency %
(3-7 mph)
0.36
0.23
0.20
0.27
0.41
0.66
0.63
0.57
2.23
2.96
1.06
0.47
0.22
0.22
0.24
0.24
Total %
(1-7 mph)
0.61
0.44
0.39
0.51
0.67
0.95
1.00
0.88
3.12
3.94
1.53
0.79
0.40
0.35
0.53
0.42
TOTAL
5.56
11.11
16.67
*Wind directions that will affect the Weisner Subdivision which is the highest
concentration of residences within one mile of the proposed facility.
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It has been estimated by Northglenn's engineer that sludge will be
removed from the plant every three to five years. Some odor is possible
during dredging. Measures such as dredging only on calm days which limit
the transport of odors or on days which the prevailing wind direction is
away from developed areas would reduce odor complaints. Also, the
operation should be well planned so the dredging process is completed in
the shortest period of time and the sludge removed to the disposal site.
Final sludge disposal will be by tank truck injecting the sludge
into nearby agricultural land. There are expected to be minimal odors
from this operation.
Aerated lagoons generally are a reliable treatment method that have
few plant upsets. The Northglenn plant design is based on a concept that
has not been proven in full scale operation. The process according to
Northglenn's engineer will control algae by limiting the carbon source
through removal of alkalinity by total nitrification. Presuming the
continued operation of the aeration system, there should be little likelihood
of plant upsets and operational problems that would result in odors.
However, it is more probable than not that algal blooms will occur each
spring or early summer, and that odors from the decaying algae will be
experienced. (See Appendix E.)
Considering the general southeast to southwest wind direction and
speed in the vicinity of the plant during worst case stability periods,
and the likelihood of strong odor problems at the plant, the frequency
of odor problems for residences near the proposed lagoons is expected
to be infrequent with the operation of the aeration facilities.
Although residences within a half mile of the facility may experience
doses of odor under certain wind conditions, the closest residential
area, the Weisner subdivision, is not in the direction that the pre-
vailing winds blow during expected worst case conditions. Odor problems
are possible if discharges from the reservoir to the Bull Canal have
high concentrations of algae. Distribution throughout the canal system
could mean that the canals themselves could generate some odors. The
frequency with which such canal source episodes may occur depends upon
the independent probabilities of algal blooms, calls for irrigation
water, and requisite meterological conditions.
ENERGY
Energy Sources
With the rising costs of conventional energy sources it has become
necessary to evaluate the cost-effectiveness of alternative sources of
energy. Several additional sources are available. Wind and solar energy
sources are the most feasible alternatives to consider for this project.
Solar energy is a clean energy alternative. Several types are
commercially available, the variation being in the medium used, i.e.
air, water, etc., depending on the type selected and the solar charact-
eristics of the geographical location.
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The Northglenn project includes a control building at the aerated
lagoon treatment plant. The building design has incorporated passive
solar design features including window positioning and partial burying
to conserve heat. The building design also has included a heat recovery
system that will heat the building with heat recovered from aeration
blowers.
Another form of alternative energy is the conversion of wind forces
into electrical power. • . ,
For wind energy to be an economical power source the average annual
wind speed should be greater than 10 mph - ideally at least, 14 to 15 mph,
since this criterion is essential for a cost-effective design.
An approximate cost of wind energy is $25/sq.ft. of rotor. The
rotor area is dependent on the quantity of energy required. At current
energy costs the capital recovery time for a wind energy system is 6 to
16 years, depending on the type of application
Wind energy could potentially be used to supply the power necessary
to operate the aeration system of the proposed Northglenn treatment plant.
The average annual wind speed at Stapleton Airport is 9.5 mph (31). This
value is close to the critical value (10 mph). Anemometer data at the
treatment plant site are necessary for final analysis.
Energy Demands
To ascertain the energy demands of the proposed Northglenn treatment
system, the power requirements (KWH per year) for the installed aeration
horsepower for the Northglenn site have been compared to the total estimated
power requirements for the alternative of treatment at Denver Metro. The
estimated power requirements herein presented for these and other systems
are based on information presented in Appendix E.
The estimated energy requirements for conveyance for the proposed
Northglenn system based on flows and information supplied by Sheaffer and
Roland, Inc., is 0.75 x 10 KWH per year. To the previous energy require-
ments for Northglenn, a conservatively estimated 0.36 x 10^ KWH per year
should be added to account for sludge handling and disposal, Bull Canal
Reservoir discharge pumping, chlorination, and other miscellaneous energy
requirements. The energy requirement for the proposed lagoon system,
conveyance and miscellaneous energy requirements is 6.88 x 10^.
The energy requirement of the Denver Metro alternative includes the
energy required for secondary treatment plus biological nitrification of
Northglenn's share of the flow at the Denver Metro treatment plant. The
estimated energy requirement is 4.14 x 10 KWH/yr.
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The Northglenn system will provide irrigation water which has
relatively high concentrations of nitrogen. With proper control of
application rates by irrigators there may be a reduced need for fertilizer
resulting in a savings of energy that would be required for the manufacture
and application of fertilizer. This energy savings was not quantified nor
included in the estimate of Northglenn1s energy requirement since it is
uncertain if farmers will actually change current fertilizer practices.
The estimated energy requirements for the Denver Metro treatment
and for the proposed Northglenn system are summarized in Table 4-12. The
results indicate that compared to other alternatives, the proposed
Northglenn system is energy inefficient and requires 66 percent more
than the Denver Metro wastewater alternative.
TABLE 4-12
COMPARISON OF ANNUAL ENERGY REQUIREMENTS
FOR PROPOSED NORTHGLENN TREATMENT SYSTEM AND SELECTED ALTERNATES
Treatment
Annual Energy
Requirements
(KWH/yr)
Proposed Northglenn System
Lagoon system only
Conveyance & miscellaneous
Total
Denver Metro
Without conveyance
With conveyance
Total
5.76 x 106
1.12 x 106*
6.88 x 106
3.13 x 10
1.01 x 10C
4.14 x 10*
6
* The energy requirement necessary to pump make-up
water is 0.41 x 10* KWH/yr. and is included in the
total conveyance and miscellaneous requirement.
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AESTHETICS
Visual Features
The proposed reservoir and lagoons will alter the topographic features
of the immediate area. The greatest impact will occur during construction
when exposed soil will contrast with surrounding vegetation. However, as
vegetation establishes on the slopes of the facility this impact will be
significantly reduced. Analysis of the visual features of the area indicates
that the terrain of the area will aid in further reducing the visual effects
beyond the immediate site.
The proposed facility, lagoons and reservoir, is illustrated on the
cover of this report. The rendering is looking north with the Bull Canal
illustrated in the upper left hand corner. Shown in Figure 4-5 and 4-6
is the facility in profile. Figure 4-5 is the north-south axis viewed
from the west. Figure 4-6 is the east-west axis viewed from the south.
The vertical and horizontal scales differ for illustration purposes.
Figure 4-7 to 4-10 are "before" and "after" illustrations of the facility.
Figures 4-7 and 4-8 represent the fiew from Weisner Subdivision, south
of the proposed site. Figures 4-9 and 4-10 represent the view of the
site from Interstate 25, north of the Base Line Road intersection (Weld
County-Adams County Line).
EPA concludes that due to the revegetation effort planned by North-
glenn and the low profile of the facility, the visual intrusion is a minor
impact.
OTHER ISSUES
Noxious Weeds
Under Colorado State law, counties are empowered to establish weed
districts. A district is responsible for controlling noxious weeds within
its jurisdiction. If a complaint comes to the administrator of the
district, (generally the County extension office) the landowner is notified
that steps must be taken to prevent the weeds from going to seed. If
corrective measures are not taken the administrator can spray the land and
charge the landowner by adding the fee to his taxes.
Concern has been expressed that Northglenn-owned agricultural land
may not remain in continuous cultivation and a noxious weed problem may
develop.
Western Adams County currently does not have a designated weed
district that encompasses the Northglenn-owned land. Southwestern Weld
County does have a weed control district that does include Northglenn
owned land. Northglenn is exempt from paying taxes. Therefore, should a
weed problem develop on their land the weed district would not be able
to assess cost to Northglenn through the defined channels. At this time
there is no enforceable policy for controlling weeds on Northglenn-owned
land in either Adams or Weld County. Northglenn staff members have, however,
publicly expressed their intention to control weeds on city-owned lands.
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Project Impacts Upon Urbanization
The Northglenn water resource management plan has significant im-
plications for urbanization of the Denver area.
Following implementation of the plan, Northglenn will control water
from the South Platte River that historically irrigated approximately
1390 acres of land. Future development of this land may be severely
limited if water is not available. Should developers follow Northglenn's
option to purchase agricultural water from the South Platte forms there
could be a further reduction in agricultural lands as a result of the
urban development. This "domino" effect, over the long-term, may have
a major impact on the agricultural community around Denver.
The key to controlling this effect is in Northglenn's ability to manage
their water so that as much of the land historically irrigated is maintained
as such.
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VISUALJMPACTS
LOOKING EAST
i
N
CROSS SECTION
SUBDIVISION
HOUSING
DEVELOPMENT
'•**•'•**"*"" * • Y*I
Horizontal I »". = 1500 ft
Horizontal Distance in Fee
to horizontal exaggerate ,s 15 to I)
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91
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-4-
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FIGURE 4-8
Future view looking North
from Weisner Subdivision
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-+ m
o -+•
I ? '
-4- O
x 3
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CHAPTER 5
STEPS TO MINIMIZE ADVERSE EFFECTS
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and
now Ln the^ifi concern ^ofi Me. good
the. nation'A
hA.p -c6 an
one.. SoJJt Zi the. /LOW
o^ aQtu.o.uLtiine.. fi'e can pave -cŁ, OA we
can iaue It, fenowcng ^f-ai whatejoeA cfco-tce
we mafee MW!/^ px.ofioandty -tn^fuence
OfJ unborn ge.neAation&.
Gus Speth, Chairman
Council on Environmental Quality (1978)
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CHAPTER 5
STEPS TO MINIMIZE ADVERSE EFFECTS
Significant adverse impacts that may result from the proposed
plan have been identified and discussed in Chapters 3 and 4. There
are two mechanisms available to EPA and the State that will insure
appropriate mitigation measures are implemented by Northglenn. These
mechanisms are:
1) EPA Grant Conditions; and
2) State Enforcement of NPDES Permit Requirements
Under EPA's Construction Grants Program, a grant offer contains a
list of requirements that the grantee must agree to in order to
receive the grant. Usually these grant conditions involve certain
steps that the grantee must accomplish during the construction phase
(e.g. finalization of an operation and maintenance manual, completion
of an industrial cost recovery system, etc.). Withholding final grant
payment is the usual mechanism that EPA uses to insure compliance with
grant conditions. Grant conditions to assure continuous requirements
can also be imposed by EPA effective for the design life of the
project.
Effluent discharge requirements of the EPA and the State are
enforceable through the National Pollutant Discharge Elimination
System (NPDES) permit system. This program requires that any
municipality, industry, or other entity discharging into waters of the
United States must do so with an approved discharge permit. The
authority for the NPDES permitting system lies with EPA, but in many
states, including Colorado, the administration of the system has been
delegated to a state agency (in Colorado it is the State Health
Department). The NPDES Permit includes appropriate limitations on the
quantity, quality, and location of the discharge.
During the development of this document, extensive discussion has
been held with Northglenn and various affected parties regarding the
identified impacts and options for minimizing these impacts. Some of
the specific mechanisms that will be used to implement and enforce the
mitigation procedures are being negotiated, while certain ordinances
designed to reduce adverse effects have already been passed by the
City of Northglenn.
Northglenn has concurred that certain impacts will require
mitigation, particularly those associated with degradation of Bull
Canal and the resulting public health risks. EPA has developed the
following mitigating programs for the impacts identified:
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Public Health Measures
Additional disinfection to reduce risks due to public
contact with the wastewater*
Additional disinfection or replacement of Dacono's
nonpotable water supply*
Tail water Control Plan*
Agriculture Reuse Manual
Commitment to use effluent for agricultural purposes
Additional measures to prevent groundwater seepage
Additional monitoring of the Bull Canal, groundwater, crops
and soils
Resolution of Management Agency Designation
Previously required mitigating measures, including:
Compliance with the State Air Quality Implementation Plan,
including:
a. Limiting sewer taps
b. Limiting development to within urban service
areas and contiguous to existing development by
prohibiting connections to the Northglenn
interceptor
c. Conformance with Section 176(c) of the Clean Air
Act regarding limitations on federal assistance
Protection of Treatment Capacity
Urban Runoff Controls
Erosion Controls
Energy Conservation
Water Conservation Efforts
Radiological Emergency Response Plan
Archaeological/Historical Resources
* Indicates EPA will negotiate for these conditions to be
included in the State-issued NPDES Permit.
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An explanation of the need for these measures and the applicable
permit or grant conditions follows:
PUBLIC HEALTH - PUBLIC ^CONTACT WITH WASTEWATER
Farm irrigation practices and public recreation around the Bull
Canal indicate that there is the potential for disease transmission
through direct body contact.
The draft discharge permit from the Colorado Department of Health
proposed that effluent be disinfected to a level of 1000 fecal
coliforms per 100 ml. Detailed review of the medical literature (see
Appendix C) indicates that public health risks are associated with 100
percent effluent chlorinated to 1000 fecal coliforms/100 ml. Because
the project would entail uncontrolled use of effluent, meaning there
would be human contact with the water during irrigation and possibly
during use of the canal for recreation, a more stringent disinfection
criteria should be applied. Therefore, the City of Northglenn has
agreed to chlorinate the effluent to a level of 200 fecal coliforms
per 100 ml. EPA will require that the 200/100 ml fecal limit become a
requirement of Northglenn's NPDES permit. Whereas the City's engineer
reports that the initial design included facilities to provide this
level of disinfection, the operational plans did not. EPA anticipates
that a dosage of 15 mg/1 chlorine as projected by Northglenn will
provide the necessary level of disinfection.
The NPDES permit effluent limitation shall be: "The City shall
chlorinate the effluent prior to discharge to achieve a criteria such
that the geometric mean of fecal coliform bacteria shall not exceed
200 colonies per 100 milliliters on a 30 day basis and shall not
exceed a criteria of 400 fecal coliform colonies per 100 milliliters
on a seven day basis."
PUBLIC HEALTH - DACONO IRRIGATION SYSTEM
The Town of Dacono has a nonpotable water system which draws
water from the Bull Canal and is provided without treatment, for
irrigation in certain parts of the town. The degraded quality of the
water in the Bull Canal will create an unnecessary health risk within
Dacono. Northglenn will resolve this problem either by substituting
an alternative water source for Dacono's use in place of the Bull
Canal water currently used, or installing and operating a disinfection
system on the water Dacono receives from the Bull Canal. If
disinfection is chosen, the system will be designed to achieve a level
of disinfection acceptable to EPA which shall include a residual
chlorine level of not less than 0.3 mg/1.
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EPA is negotiating to include the following as an NPDES permit
condition and will require as a grant condition: "Northglenn will
undertake the cost of modifications, operation and maintenance for the
Dacono nonpotable water supply to insure that the nonpotable water
supply for the Town of Dacono is properly disinfected to protect
public health."
Alternatively at Northglenn's expense, a replacement for this
system could be provided, in which case this permit condition would be
withdrawn. Northglenn shall consult with the Town of Dacono to obtain
their concurrence with these plans.
PUBLICJHEALTH - TAILWATER CONTROL AT FREDERICK AND FJRjSSTONE
During irrigation periods, Bull Canal tailwater from lands
adjacent to Frederick and Firestone flows through town streets.
Northglenn has agreed with EPA to provide necessary facilities to
control the tailwater so that it will not enter the Towns of Frederick
or Firestone. The plan, which has been conceptually developed, will
consist of three ponds that will receive the tailwater from collection
ditches at the edge of these fields adjacent to the towns. Low dikes
will reduce stormwater inflow into these ponds. Water from the ponds
will be recirculated back to the irrigated land. (Should these fields
be irrigated during rainfall, some diluted tailwater could flow into
the streets.) According to the filings Northglenn has made with the
Water Court, their position is that this water is from Standley Lake
storage and impounding of this water will not create a water rights
problem. EPA concludes that if the Water Court disagrees, this
problem would then have to be resolved in Northglenn's augmentation
plan.
EPA is negotiating to have the following as an NPDES permit
condition and will require as a grant condition: "Northglenn will
provide physical measures to prevent the flow of tailwater from
adjacent agricultural land into the Towns of Frederick and Firestone
or any other residential area. Consultation with Frederick and
Firestone on the design and location of these facilities is necessary."
PUBLIC HEALTH - FOOD CROP PRODUCTION AND GARDENS
In 1979 there were no raw edible food crops grown in the
FRICO-Stand ley Lake System. However, there is potential for such
crops to be grown in the future. Also, there is potential for private
gardens within the FRICO area to be irrigated with Bull Canal water.
Regarding the possible irrigation of private gardens, Northglenn
has agreed to develop an educational plan that will inform farmers of
the problem and discourge direct contact with the water and its use on
private gardens.
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The EPA grant condition will be: "Northglenn agrees to issue and
reissue an advisory on an annual basis for the design life of the
plant, to all shareholders of record in the Stand ley Lake Division of
FRICO, and to all shareholders of record of any other division of
FRICO to which waters from the Northglenn reservoir are diverted.
This advisory concerns the constituents of the wastewater in the
reservoir and a notice that such water should not be used for the
irrigation of raw edible vegetable crops."
AGRICULTURAL REUSE MANUAL
The proposed project will result in delivery of reclaimed
effluent and Standley Lake water to FRICO farmers. The reclaimed
water is suited for agricultural uses, with the exception of raw
edible vegetables as noted above. There may be some minor operational
changes that can or should be made by the farmers for certain crops.
For example, one change that would be advised is the modification of
fertilization rates to compensate for the nitrogen content in the
wastewater applied. The City of Northglenn has agreed to prepare an
Agricultural Reuse Manual that will provide information on such
matters. This manual will be available to all farmers in the
FRICO-Standley Lake Division. Projections regarding water delivery
and quality would be updated monthly. A preliminary outline of the
manual is given below:
A. Water Yield Projections
1. Snow survey
2. Standley Lake Yield
a. Bull Canal Shares
b. Reuse Water
B. Water Delivery Projections
1. Crop Projections
a. Type
b. Acres
2. Standley Lake
a. Cities
b. FRICO Delivery
3. Bull Canal Reservoir
a. Wastewater
b. Makeup Water
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C. Nutrient Delivery Projections
1. Bull Canal Reservoir Qualities by Month
2. Recommended Commercial Fertilizer Application Rates
3. Crop Advisories
D. Adjustments to Delivery Projections
1. Standley Lake Quantity and Quality
2. Bull Canal Reservoir Quantity and Quality
3. Crop Advisories
4. Field Monitoring Results
E. Distribution of Reports
1. Agricultural Advisory Reports
2. Water Quality Monitoring Reports
The EPA grant condition will be: "Northglenn will develop an
Agricultural Reuse Manual to provide advice to farmers of the Standley
Lake Division of FRICO on the use of treated sewage effluent for crop
irrigation. Periodic public reporting in the advisory notices will be
provided to the FRICO Board and to anyone requesting this information."
COMMITMENT TO USE EFFLUENT FOR AGRICULTURE
Implementation of the Northglenn agricultural reuse project
requires the commitment of large sums of money, both from the City and
EPA. Assurance must therefore be given that the City of Northglenn
can and will continue the proposed means of wastewater treatment and
disposal for the design life of the project-20 years. The proposed
plan of agricultural reuse depends on the availability of sufficient
agricultural lands to receive the effluent. While EPA concurs with
Northglenn that future demand for this effluent should be adequate to
insure this, Northglenn will develop a contingency plan whereby
sufficient land under the City's control will be continuously
committed to receive the effluent. This commitment can be in the form
of land ownership by the City, irrigation easements, effluent sale for
irrigation, or effluent lease for irrigation. The commitment is for a
minimum of 20 years beyond the date of the grant award.
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Northglenn purchased 1,836 acres within the Stand ley Lake
Division incidental to water rights purchases. Fifteen hundred acres
of this land are irrigated. Northglenn's engineer estimates that a
minimum of 1,065 acres producing alfalfa will be sufficient to insure
continuous disposal of its wastewater without adverse effects on
groundwater. EPA agrees with this determination and therefore will
require as a grant condition that Northglenn maintain 1,100 acres
under their control for effluent disposal.
The EPA grant condition will be: "Northglenn shall assure that
sufficient land, approximately 1,100 acres, in the FRICO-Standley Lake
system is under their control—through ownership, lease, or
contract—for the purposes of effluent disposal. This condition is
binding for the 20-year design life of the project."
ADDITIONAL MEASURES TO PREVENT GROUNDWATER SEEPAGE
The northwest corner of the proposed reservoir may contain a
fractured zone from a fault trace known to exist in the vicinity. If
present, this would provide a zone of permeability potentially
allowing communication of the impounded fluid with the groundwater of
the immediate area. (Further analysis is provided in Chapter 4.)
Should the fracture pattern be encountered under the dike area or
on the reservoir side of the excavation, there are two possible
remedies: 1) move the reservoir south of the zone, or 2) design a
sealing method. Additional sealing methods could include a
combination of a partial membrane seal and compaction of a mixture of
the local clays and proper additives to increase the plasticity in
order to combine with the fractured zone material.
During the subsurface investigations of the reservoir site, many
shallow holes were drilled. These penetrations in the pond area range
from 23 to 60 feet below the final level of the reservoir. There are
three deep well penetrations (600 to 1,500 feet) in the area of the
reservoir. Two are USGS cased holes which exist near the northwest
corner. The third hole, drilled by Chen and Associates, has been
plugged with cement from the surface.
Northglenn proposes to use on-site clay material, at least six
inches thick, compacted to 95 percent density. EPA considers that a
six-inch liner may not be sufficient to insure a compacted
permeability of less than 10~6 cm/sec which is the design criteria.
Where the liner is in contact with natural clays, a one foot
liner would be a probable sufficient minimum. In areas where sand
lenses are present, the liner should be at least two feet thick. The
liner must be kept moist to prevent dessication cracks until completed
and filling begins. Any open cracks or fractures which are in bedrock
should be covered with a mixture of cohesionless sand and gravel to
insure liner integrity after installation.
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EPA will require the following grant condition: "During
construction of the cut-off key for the reservoir dike, a trench will
be made along the northwest boundary that will penetrate down to a
competent zone in the Arapahoe formation. An examination of the
exposed units will be made to determine if any fault traces cut across
this portion of the reservoir. If a fault trace is located within the
proposed reservoir area, either the dam will be relocated to exclude
the trace, or the trace will be sealed with an impermeable liner
before implacement of the clay liner. The results of these
investigations and any mitigative measures must be inspected and
approved by the Corps of Engineers, who will report the results to EPA.
All shallow test holes within the reservoir site that have a
depth greater than 30 feet below the pond base must be plugged with
concrete. Any test holes that have a depth of less than 30 feet must
be back filled and compacted. The cased USGS test wells (BW-77-15B
and BW-77-17B) must be pressure plugged with concrete from the bottom
up to insure proper abandonment. EPA will be notified when the
plugging is to take place so that a staff member can observe the
plugging operation.
The thickness of the clay liner will be increased over the
proposed 6 inch compacted seal for areas where the seal will be in
direct contact with sand or sandstone. Clean claystone material must
be used. In all cases the inplace claystone that will be used for a
seal must be ripped up to the required depth before compacting to the
six inch thick seal. The clay seal will be kept moist to prevent
cracking. In areas where claystone is not present, a supply of
claystone (from stockpile) must be spread in the area and a compacted
seal of at least one foot thick provided."
ADDITIONAL MONITORING REQUIREMENTS
Northglenn has agreed to monitor the agricultural exchange
program for the design life of the project. Northglenn will collect
data that relates to the potential for surface water quality
degradation caused by agricultural tailwater, groundwater
contamination from reservoir seepage, agricultural lands or irrigation
ditches, and contamination of water and subsequently crops by heavy
metals, and pathogenic organisms.
EPA will require the following grant condition: "A monitoring
program will be developed to include locations and depths of
groundwater monitoring wells, locations of surface water monitoring,
and procedures for monitoring crops. Pollutant parameters and
monitoring frequencies must be given. Domestic groundwater supplies
in the area that could be affected by the project must be identified
and periodically monitored. The monitoring program shall be modified
as information is developed on items such as the potential for crop
contamination by toxic substances.
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Test procedures for the analysis of pollutants shall conform to
regulations published pursuant to Section 304(h) of the Clean Water
Act. Northglenn will be required to retain all records and
information resulting from the monitoring activities required by this
permit condition including all records of analyses performed and
calibration and maintenance of instrumentation for the design life of
the project.
Northglenn must provide annual public reporting on the findings
of the monitoring program. Northglenn must also identify any
noneonformanee with regulations concerning the level of contaminants
in crops set by FDA, USDA, State agriculture and health departments
and other government agencies. EPA shall pay no more than 50 percent
of the federal share of the Step 3 project until the draft field
monitoring program is submitted to EPA. EPA shall pay no more than 90
percent of the federal share of the Step 3 project until the field
monitoring program is approved by EPA."
EPA will provide the Larimer-Weld 208 and Weld County copies of
the draft program for their review. A 90-day review period will be
provided. EPA will review the Larimer-Weld 208 and Weld County
comments before the monitoring program is approved. Northglenn has
submitted to EPA a preliminary program which is presented in
App end ix I.
DESIGNATION OF MANAGEMENT AGENCYjFOR THE NORTHGLENN PROJECT
The 208 Clean Water Program includes a process to identify needed
wastewater treatment works, specify financial arrangements to develop
these works, and set construction priorities. Each 208 area must also
regulate all discharging facilities and develop policies and
regulations to control all other point and nonpoint sources of
pollution, identify which agencies are to implement the 208 plan, and
assess the impact of the plan. Section 208 also calls for annual
recertification of water implementation controls, including possible
withholding of Federal grants for constructing pub 1icly-owned
treatment plants unless there is compliance with the plan.
It has been found that capital intensive and structural measures
alone such as the construction of wastewater treatment facilities,
cannot economically solve water pollution problems. Other
nonstructural solutions must be developed, such as the implementation
of land use controls to direct population growth to areas where
wastewater treatment capacity already exists or can be readily
provided.
The Clean Water Act requires that a management system be
established in each 208 plan that assigns responsibilities to specific
agencies. The system must not only assure implementation of the
original plan but must also allow for annual updating and
recertification of the plan.
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The Act further requires that responsibilities within the system
be assigned according to the following four broad functions:
continuing planning; management; operations; and regulation. EPA has
determined that these functions are properly managed when: a) local
governments and organizations control implementation of the plan
wherever possible; b) general purpose local governments are in charge
wherever possible, because they are best able to integrate water
quality programs with other local programs, and normally have the
powers needed to deliver results; c) general purpose local governments
delegate certain powers, functions, and responsibilities to
appropriate existing agencies, so that disruptions are minimal and
valuable expertise is put to use; and d) cities and counties
coordinate wastewater management in the urban fringe areas where
jurisdictions meet.
Management Agenc ies
As specified in the regulations developed for the Clean Water
Program, 208 plans shall identify a specific Management Agency to
implement each of the plan's programs. Each identified Management
Agency shall have adequate authority as specified under Section 208(c)
of the Act to establish the agency's legal, administrative and
financial authority; appropriate reporting procedures; methods for
coordination with the planning agency; and a description of the
specific implementation responsibilities of the agency. The Governor
shall assure that each Management Agency which has regulatory
responsibilities has sufficient autonomy and regulatory authority to
carry out its responsibilities effectively and on time. EPA may
withdraw acceptance of a Management Agency designation and request the
Governor to designate a new agency, or take other corrective action,
if it is determined that the effectiveness of the Management Agency is
inhibited by lack of sufficient autonomy.
Management Agencies can set up contracts that delegate
operational responsibility to the operators of wastewater treatment
facilities. The operating agency is responsible for day-to-day
operation of the facility. For example, a sanitation district could
enter into an intergovernmental agreement (IGA) as an operating agency
with a Management Agency (such as a city or county) that would define
its specific responsibilities for implementing the facility. The
sanitation district would most likely hold the effluent discharge
permit for operation, be eligible to receive Federal grants to
construct wastewater facilities, set its own rates, and have complete
control over the operation and maintenance of the facility. The city
or county, as Management Agency, would review and approve facility
expansion, set construction priorities, cooperate with the sanitation
district to carry out the 208 plan, and be responsible for broad areas
of land use planning and nonpoint source pollution control beyond the
scope of the sanitation district.
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Management Agency—Weld County or Northglenn?
The City of Northglenn is located within the 208 Areawide
Planning jurisdiction of the Denver Regional Council of Governments
(DRCOG) and has been designated as a Management Agency under the DRCOG
Plan. As such, Northglenn is eligible to receive EPA Section 201
Construction Grants funds. Northglenn will have responsibility for
any facility they construct, for issuance of bonds, grant
administration, and operation and maintenance of the facility.
In accordance with the approved Larimer-Weld 208 Plan, the
continuing planning functions in Weld County are the responsibility of
the Larimer-Weld Regional Council of Governments. Weld County has
been designated as a Management Agency under the Larimer-Weld 208 Plan
for all unincorporated areas of the county. As a Management Agency,
Weld County has a vital interest in the planning, operation and
management of all wastewater treatment facilities constructed within
their boundaries.
The proposed Northglenn wastewater treatment and reuse facility
will service only the city limits within Northglenn with an eight mile
interceptor through Adams County. The plant, however, will be located
in southern Weld County, within the jurisdiction of the Larimer-Weld
Regional Council of Governments' 208 Areawide Planning Region. This
situation is unique in Colorado and there have not been any precedents
established for designation of the Management Agency under these
circumstances. There are four alternative methods of designation:
1) Weld County would be the Management Agency and grant
recipient. Northglenn is the operating agency under the
Larimer-WeId 208 Plan:
2) Weld County would be the Management Agency. Northglenn would
be the operating agency and grant recipient;
3) Both Northglenn and Weld County would share Management Agency
responsibility with Northglenn as operating agency and grant
recipient:
4) Northglenn would be the sole Management Agency and grant
recipient.
These alternatives are further identified:
1) Weld County would be identified as a Management Agency with
Northglenn as an operating agency. Weld County would receive the
grant and would pass through the funds and operating
responsibilities to Northglenn as defined in an agreed upon
intergovernmental agreement (IGA). Thus, Northglenn would be
eligible to set its own rates and have control over the daily
operation of the facility. Weld County would have the power to
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review and approve or deny facility expansion, set construction
priorities, cooperate with Northglenn to carry out the respective
208 plans, and be responsible for broad areas of land use
planning and nonpoint source pollution control beyond the scope
of Northglenn;
2) Same as above except Northglenn would be the direct recipient
of all Federal construction grants for their waatewater treatment
facility;
3) Both Northglenn and Weld County would act as Management
Agencies as they have been so designated under their respective
208 planning agencies. Northglenn would also be identified as
the Operating Agency under the Larimer-Weld 208. The sharing of
Management Agency responsibility and the designation of
Northglenn as the Operating Agency would have to be specifically
defined in an IGA. Under this arrangement, Northglenn would be
identified as the grant recipient and would be responsible for
operating and maintaining the wastewater facility in accordance
with provisions in the IGA:
4) Northglenn would be identified as sole Management Agency and
thus would directly receive any Federal construction grant
funds. Northglenn has been identified as a management agency
under the Denver Regional 208 Plan because the service area is
located in Adams County which is under the jurisdiction of
DRCOG. If this alternative were chosen there would be no need
for an IGA, as Northglenn would be solely responsible for plant
operation, expansion or land use changes.
The requirements of both 208 plans (which have received State
certification and EPA approval) must be met, through a formal
Intergovernmental Agreement (IGA). Management Agency certification
for both Northglenn and Weld County and execution of a bilateral IGA
between Northglenn and Weld County will serve to notify the
responsible areawide agencies, State agencies, and EPA of conformance
with the 208 Plans. Alternative 3 establishes sharing of the
Management Agency responsibility and therefore best accomplishes these
goals. Consequently, EPA will require the development of the IGA
based on sharing of Management Agencies responsibilities as outlined
in Alternative 3 as a condition before receiving the final 10 percent
payment of the grant.
Conditions of the Intergovernmental Agreement
The following issues are recommended by EPA as items to be
included in an IGA between Weld County and Northglenn. Other issues
can be included by mutual consent of both parties.
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1. Advisory for Agricultural Reuse
Develop detailed agricultural reuse manual and educational
plan to advise farmers on the use of the effluent for all
crops or private gardens using the Bull Canal system. Issue
and reissue on an annual basis an advisory notice that the
effluent water should not be used for irrigation of raw
edible vegetable crops.
2. Replacement or Disinfection of Dacono Nonpotable Water System
Specify the method of complete disinfection to provide a
residual chlorine level or replacement of the nonpotable
water system for the Town of Dacono. The Town of Dacono
must be properly represented and advised on the solution to
this problem.
3. Tailwater Control
Development of physical measures to prevent the flow of
tailwaters from adjacent agricultural land into the Towns of
Firestone and Frederick, or any other residential area.
Assure that Weld County and the communities of Firestone and
Frederick are properly represented and advised on the
solutions to this problem.
4. Land Use Au thor ity
The IGA should establish: a) Weld County's authority for
zoning and land use planning in the area surrounding the
treatment/reuse facility; b) Northglenn's authority for taps
into the project interceptor; and c) Northglenn's authority
for plant expansion. (Northglenn would not require Weld
County approval for expansion within the boundaries of
Northglenn.)
5. Sludge Disposal
Northglenn would be creating sludge waste for possible
disposal within the LWRCOG 208 plan area and therefore must
comply with appropriate regulatory requirements in the
disposition of such wastes. Northglenn plans to dispose of
sludge through agricultural reuse on agricultural land in
Weld County and Adams County.
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6. Add it ional Monitor ing Requirements
EPA will require, as a grant condition, a field monitoring
plan of the agricultural exchange program for the design
life of the project. Northglenn will collect data that
relates to the potential for surface water quality
degradation caused by agricultural tailwater, groundwater
contamination from effluent seepage, agricultural lands or
irrigation ditches, and contamination of water and
subsequently crops from materials such as heavy metals or
pathogenic organisms.
The monitoring program would be developed by Northglenn.
EPA would provide the Larimer-Weld 208 and Weld County
copies of the draft program for their review. A 90-day
review period would be established and EPA would review the
Larimer-WeId 208 and Weld County comments before the
monitoring program is approved.
Northglenn should provide annual public reporting on the
findings of the monitoring program. Northglenn must
identify any noneon formanee with regulations of the level of
contaminants in crops set by FDA, USDA, State agricultural
and health departments and other governmental agencies.
The IGA should consider the possibility of the Weld County
Health Department processing some of these samples as a
method of independent review. Northglenn would then
reimburse Weld County for such expense. Assurances must be
provided for the long term financial liability of Northglenn
for this water quality monitoring program.
7. Protection of Groundwater Quality
Plans would need to be established to deal with possible
groundwater pollution. Such plans should consider the
groundwater monitoring program and a contingency plan to
replace, at Northglenn's expense, the supply of water to
residents presently dependent upon groundwater, if
contamination is caused by this facility.
8. Limits on New Interceptors
A tap restriction prohibiting Northglenn from building any
interceptors to the facility without prior Weld County
approval should be included.
EPA will require the following grant condition: "The City of
Northglenn and Weld County shall share responsibilities as Management
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Agencies under their respective 208 Water Quality Plans. Designation
of said responsibilities shall be incorporated into an
Intergovernmental Agreement following as a minimum those EPA
recommendations as outlined above. EPA shall pay no more than 50
percent of the federal share of the Step 3 project until the draft
Intergovernmental Agreement is submitted to EPA. EPA shall pay no
more than 90 percent of the federal share of the Step 3 project until
the Intergovernmental Agreement is signed by the two parties and
approved by EPA and the State."
See Appendix K for a draft of the Intergovernmental Agreement
written by the City of Northglenn. Weld County has not agreed to this
draft IGA. EPA believes the draft IGA basically complies with the
above recommendations with two exceptions. The disinfection standard
for the Dacono system shall be a residual chlorine level of not less
than 0.3 mg/1 and not as indicated in the draft IGA of a "fecal
coliform level no greater than the level existing immediately upstream
of the Northgienn treatment Facility." In addition, the IGA should be
more specific in respect to sludge disposal requirements. The draft
IGA contains additional provisions beyond EPA requirements including
dismissal of pending litigation and payment in lieu of taxes.
PREVIOUSLY REQUIRED MITIGATING MEASURES
When EPA issued its initial environmental assessment on the
Northglenn facility in September, 1978, several measures designed to
reduce adverse impacts were identified. All Denver area communities
which request EPA sewage funds must comply with EPA provisions as
developed in the Denver Overview EIS. (see Final Action on the Denver
Regional Environmental Impact Statement for Wastewater Facilities and
the Clean Water Program, August, 1978). For the City of Northglenn
these conditions .include:
Compliance with the State Air Quality Implementation Plan,
including:
a. Limiting sewer taps, and
b. Limiting development to within the urban service area and
contiguous to existing development.
c. Conformance with Section 176(c) of the Clean Air Act
regarding limitations of federal assistance
Protection of Treatment Capacity
Urban Runoff Controls
Erosion Controls
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Energy Conservation
Water Conservation Efforts
Radiological Emergency Response Plan
Archaeological/Cultural Resources
With certain limited exceptions, EPA has accepted Northglenn's
efforts to fulfill these conditions. The current status of these
efforts includes the following:
Air Quality
The funding of wastewater treatment and collection facilities
that involve the addition of capacity to serve future population
growth should be done in a manner encouraging the implementation of
measures to reduce the existing air pollution problem. These measures
are described in Chapter 4 under the Air Quality Section.
Northglenn will meet the four requirements specified in the
Denver Overview EIS through the following provisions:
a. A resolution adopted by the City Council indicating
compliance with all measures developed in the Denver element of
the State Air Quality Implementation Plan.
b. An ordinance limiting the number of taps available on an
annual basis.
c. Ordinances prohibiting new taps along the proposed new
interceptor.
On November 16, 1978, Northglenn adopted Resolution No. 78-92
which states in part that:
"The City shall develop, implement and strictly enforce
a comprehensive set of ordinances, policies and programs designed
to produce and maintain ambient air quality standards:
The City shall actively participate in the planning,
research, and development of the Denver element of the State Air
Quality Implementation Plan;
The City shall cooperate to the fullest extent possible with
the Denver Regional Council of Governments in the development of
such a plan; and
The City shall upon approval of such plan by the
Environmental Protection Agency, enact and enforce an air quality
ordinance for the purpose of ensuring compliance with the plan
and with the goals of the Clean Air Act, as amended in 1977."
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The City of Northglenn adopted, on December 21, 1978, an
ordinance (Number 529) providing for a sewer tap program which
annually determines the number of taps available for new residential
development. The ordinance also provides a penalty for violation.
The ordinance specifies that it is unlawful for any person to
make any connection to the City's sanitary sewer system without first
obtaining the City Manager's approval of such connection. The
ordinance indicates that the City Manager shall grant approval of
applications for residential connections to the City's sanitary sewer
system consistent with and not to exceed the following schedule:
MAXIMUM ANNUAL CUMULATIVE
YEAR RESIDENTIAL RESIDENTIAL
1978 430 430
1979 430 860
1980 431 1291
1981 431 1722
1982 431 2153
1983 431 2584
1984 431 3015
1985 431 3446
Any connections not used in any one year may be added to the next
succeeding year's allowable number of connections, except that in no
year shall the total of all connections permitted exceed the
cumulative total allowable for that year.
Any person violating the terms of this ordinance shall, upon
conviction, be guilty of a misdemeanor and shall be subject to a fine
not to exceed Three Hundred ($300.00) dollars, or imprisonment in the
City or County jail not to exceed ninety (90) days, or both such fine
and imprisonment.
In order that the proposed new interceptor will not unduly
interfere with the adopted land use policies of Thornton and Adams
County, and in order to provide for contiguous development, Northglenn
has agreed to an EPA condition that prevents connections to the
Northglenn interceptor. By City Ordinance adopted December 21, 1978,
Northglenn amended its municipal code to include:
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"Section 16-11-5. Prohibition Against Connections to ^
Northglenn Interceptor. It is unlawful for any person to
directly or indirectly connect any collection system,
interceptor, pump station, or other means of conveying
sewage, to the Northglenn Interceptor as set forth on the
map filed in the office of the Director of Public Works, for
that section of the interceptor which is located outside of
the City's corporate boundaries, and running from the
incorporated boundaries to the sewage treatment facility,
except the area between 120th Avenue and 136th Avenue, which
exceptions are subject to approval by both the City and the
United States Environmental Protection Agency."
Any person violating the terms of this ordinance shall be guilty
of a misdemeanor and subject, upon conviction, to a fine not to exceed
Three Hundred ($300.00) Dollars, or by imprisonment in the City or
County jail not to exceed ninety (90) days, or both such fine and
imprisonment."
On April 1, 1980 EPA published in the Federal Register an advance
notice of proposed rulemaking to implement section 176(c) of the Clean
Air Act. The notice describes a regulatory approach which provides
that:
States'will establish procedures for the review of federal
conformity determinations as a part of their state
implementation plans (SIPs)
St
Federal departments will establish procedures for
determining the conformity of their actions with SIPs.
The federal departmental responsibilities may generally be
satisfied by the use of existing notification and review procedures
such as this EIS. Because the rulemaking may take almost one year to
complete, EPA and other federal departments will establish interim
procedures for determining the conformity of federal actions to
approved and promulgated SIPs. Each agency including EPA must ensure
that their environmental documentation to meet the procedural
requirements of the National Environmental Policy Act will contain
sufficient information to make the following findings:
1. All necessary state and federal air quality permits have
been obtained for the activity. If a state variance has
been issued, then it must be in conformity with the
requirements of the Clean Air Act;
2. All population projections provided in the supporting data
base for the action are consistent with the population
projections used in the SIP;
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3. The stationary, area and mobile source emission growth rates
that are provided in the supporting data base for the action
are consistent with the emission growth rates used in the
SIP;
4. The increased emissions resulting from the action do not
conflict with the emission reduction requirement of the SIP;
5. The increased emissions resulting from the action do not
exceed the area's increment for the prevention of
significant deterioration of air quality;
6. The increased emissions resulting from the action do not
contribute to the violation of any national ambient air
quality standard;
7. The action is consistent with all the transportation control
measures that are provided for the SIP; and
8 The action complies with all other special provisions and
requirements of the SIP.
EPA has reviewed the Northglenn Wastewater Facilities Plan and
finds that it conforms with the Colorado State Implementation Plan
(SIP) in accordance with Section 176(c) of the Clean Air Act. Before
EPA makes a final conformity determination and proceeds with project
funding, the formal views based on review of the final EIS of the
Colorado Air Quality Control Commission and the Denver Regional COG
will be carefully considered as well as those views of the public.
Initial discussions have been held with DRCOG and the Air Quality
Control Division. EPA believes that funding of the Northglenn project
conforms with the Colorado State Implementation Plan (SIP) on the
following basis:
Determination Requirements defined
in the Advance Notice of Proposed
Rule Making Federal Register,
April 1, 1980.
Discussion of Finding
1. The proposed facility does not
require state or federal air
quality permits for operation,
because it does not emit materials
during operation that contribute to
standards violations. Construction
emissions permits specifying
control measures for fugitive dust
have been obtained by Northglenn
from the Colorado Air Quality
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Control Division. (Three Emission
Permits for Fugitive Dust were
issued on August 23, 1979. Permits
include numbers C-12,357-1FD, 2FD,
and 3FD for site preparation, force
main construction and the pump
station.)
2., 3., 4., 6., The proposed facility will support
growth in Northglenn, which is part
of the Denver Region nonattainment
area, by providing additional
treatment capacity. Community
growth contributes to air quality
problems because additional people
produce more auto travel and
associated exhaust emissions. Auto
emissions are the primary cause for
nonattainment in the Denver region.
The residential growth supported by
this project is reflected in the
DRCOG Regional Growth and
Development Plan (RGDP) which
formed the basis for all analytical
work in the SIP. The size of the
wastewater facility is based on the
1976 DRCOG population projections
for Northglenn which are also used
in the RGDP. Thus, the projections
of future air quality and the
analysis of controls in the SIP
account for the increase in auto
emissions over time that are
associated with higher residential
population in Northglenn.
Furthermore, as previously
described Northglenn has adopted
Ordinance Number 529 limiting the
number of sewer taps available
annually to 430 taps, which is
consistent with the DRCOG estimates
for growth rate. The City of
Northglenn has agreed to an EPA
grant condition that prevents any
connections to the proposed sewer
interceptor a provision which
encourages contiguous growth as
called for in the RGDP policy. In
addition EPA has required that
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before facility expansion occurs or
any new interceptor is approved,
Northglenn must obtain another
conformity determination. For
these reasons, EPA believes that
the subject considerations have
been met and that no additional
analysis is necessary.
5. Not applicable in nonattainment
areas.
7., 8. The City of Northglenn has
committed to participate in the
development and implementation of
the SIP effort. There are no
specific measures required under
the SIP for the city at this time.
EPA accepts these actions of the City of Northglenn to be in
compliance with agency policy to minimize air quality impacts within
the Denver urban area. Accordingly, EPA will require the following
grant condition:
"Northglenn shall execute those items specified in City
Resolution Number 78-94 regarding its intention to implement and
enforce compliance with the provisions of the Denver element of the
State Air Quality Implementation Plan. Northglenn shall maintain an
ordinance providing for sewer tap limits as defined in Ordinance
Number 529 adopted December 21, 1978 or as amended. The City shall
maintain a prohibition against connections to the Northglenn
interceptor for areas outside the current city limits as specified in
Section 16-11-5 or as amended, of the municipal code. The City shall
not expand the wastewater treatment facility or construct any new
interceptor to transport sewerage to the wastewater treatment facility
intended to service areas outside the current city limits unless they
first obtain concurrence from the appropriate metropolitan planning
organization designated under Section 134 of Title 23, United States
Code, the State Air Quality Control Division and EPA that such actions
conform to the State Air Quality Implementation Plan in accordance
with Section 176(c) of the Clean Air Act. The Regional Administrator
may withhold, condition, or restrict the Step 3 grant in the event
that he determines that the provisions of Section 316 (b) of the Clean
Air Act of 1977 have been met."
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Protection of Treatment .Cap_ac_i_ty_
According to EPA's cost-effective regulations the design life for
the Northglenn facility is 20 years. Northglenn is expected to have a
population growth rate of 3.1 percent per year resulting in a
population estimate of 42,500 people by 2000. The wastewater
treatment facility has been designed to accomodate flows for this
population. Substantially higher rates of development due to rapid
growth of Northglenn or expansion of the service area would create the
need to expand the facility before 2000. Managing growth within these
limits reduces the likelihood the city would need to expand the
facility within the design period. Measures to protect treatment
plant capacity are encouraged by EPA.
Northglenn's ordinances as described in the previous section
under Air^ Quality, limit the number of new sewer taps on an annual
basis and prevent any connections to the proposed interceptor. These
ordinances are sufficient to protect treatment plant capacity. In
order to ensure Northglenn will continue to abide by these
restrictions EPA is negotiating to have the following NPDES permit
condition:
"The City of Northglenn shall maintain an ordinance
providing for sewer tap limits as defined by Ordinance Number 529
dated December 21, 1978 or as amended by the City Council. The
City shall maintain a prohibition against connections to the
Northglenn interceptor for areas outside the current city limits
as specified in Section 16-11-5 or as amended to the municipal
code."
Urban Runoff Controls
The Denver Regional Council of Governments recommended in the 208
Clean Water Plan that urban runoff pollution be controlled by
nonstructural controls such as pollution control ordinances (see
Denver Overview Final EIS, Volume 1, page 33). The use of structural
pollution controls to collect and treat urban runoff was believed to
be too expensive to justify at this time. Accordingly, EPA determined
that prior to granting funds for construction or expansion of
wastewater facilities, the general-purpose governments within the
proposed service area must show progress, in the form of ordinances
adopted or recent efforts taken, towards implementing the nonpoint
source controls recommended by the Clean Water Plan. Northglenn has
met this requirement with respect to urban runoff control by adopting
a new ordinance to their municipal code entitled "City Urban Runoff
Drainage Ordinance".
Specific water quality purposes of this ordinance (Section 16-13
of the Municipal Code of Northglenn) include:
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a) A coordinated program of creating upstream ponding for
temporary detention of storm runoff waters;
b) Encouragement and facilitation of urban water resources
management techniques, including detention of storm runoff,
minimization of the need to construct storm sewers, reduction of
pollution, and the enhancement of the environment.
The Urban Runoff Management Plan, based on engineering studies,
indicates the location of all drainage facilities in the Cijty,
including those facilities which presently exist and those which are
determined to be needed in the future. The facilities shown on the
plan include all major drainage ways which directly or indirectly
affect drainage within the City, and all conduits, channels, natural
drainage courses, retention reservoirs, easements, culverts, bridges
and other facilities which are required to provide for the drainage
and control of surface waters within the basins of the drainage ways
and to carry such waters to designated points of outflow or discharge.
Maximum citizen participation during all phases of the
implementation of the storm drainage and flood control regulations is
encouraged.
To insure citizen participation on actual construction projects,
any time a project is proposed by the City to implement the Urban
Runoff Management Plan, the City administration will hold a public
hearing in the neighborhood where the project is to be constructed.
The Planning Board and City Council shall hold public hearings prior
to construction of the project.
EPA accepts this ordinance as written as suitable to meet the
requirements of an urban runoff control plan. Accordingly, EPA will
require the following grant condition:
"Northglenn shall maintain for the design life of the
project an urban runoff control plan similar to the
provision contained in Ordinance No. 531 entitled "Urban
Runoff Management Plan or as amended."
Erosion Control
Northglenn had agreed to implement erosion control measures by
passing City Resolution Number 78-102, adopted December 21, 1978. The
resolution called for adoption of an erosion control ordinance by
June, 1979. Northglenn has failed to implement this provision to
date. Accordingly, EPA will require Northglenn to adopt measures to
limit erosion and to control sediment prior to final payment of the
grant. Northglenn has been notified to prepare an ordinance
specifying erosion controls and to follow: Guide for Erosion and
Sediment Control in Urbanizing Areas of Colorado; Interim Guidance,
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prepared by the U.S. Department of Agriculture, Soil Conservation
Service, Denver, Colorado, 1977. EPA will not award final payment of
the Step 3 grant until the grantee has adopted appropriate ordinances
or requirements to implement the erosion and sediment control
requirements for new development as included in the DRCOG 208 Clean
Water Plan.
Energy Conservation
EPA requires that during the planning or design of any wastewater
treatment works, the consideration of solar energy technology and
energy conservation techniques must be demonstrated by showing that
energy requirements, particularly for natural gas, have been reduced
as much as possible.
The Northglenn lagoon system is not a particularly energy
efficient method of treatment (see discussion under energy demand in
Chapter 4). The agriculture reuse system reduces energy requirements
by continuing to produce agricultural products near the Denver area
which will reduce transportation costs and by providing nutrient
recycling should reduce the use of inorganic fertilizers produced with
natural gas.
The Northglenn project includes a control building at the aerated
lagoon treatment plant. The building design has incorporated passive
solar design features including window positioning and partial burying
to conserve heat as illustrated on the cover of this report. The
building design also has included a heat recovery system that will
heat the building with heat recovered from aeration blowers, by
utilizing a heat pump.
EPA concludes no further measures are necessary regarding energy
conservation.
Water Conservation
EPA regulations for cost-effective analyses specify that adequate
consideration be made for reducing wastewater flow (generally called
water conservation) for communities over 10,000 population discharging
wastewater greater than 70 gallons per capita per day (gpcd). Under
these circumstances, the grantee must use the estimated future
reduction in flows for wastewater facility design.
The current average potable water use in Northglenn has been
measured at 144 gpcd with an average of 91 gpcd returning as
wastewater flow. Of the total wastewater flow, 18 gpcd are attributed
to either industrial sources or groundwater infiltration, leaving an
estimated 73 gpcd of residential wastewater flow. Because
Northglenn's current use is so close to 70 gpcd criteria, EPA
determined the formal cost-effective analysis of wastewater flow to be
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unnecessary, especially since Northglenn's plan includes several
methods for reducing water use. The proposed methods include
mandatory water saving devices for new construction and remodeling,
outdoor irrigation reduction measures, and economic incentives for new
taps to minimize water use.
Northglenn has adopted Ordinance Number 555 which establishes
fees and charges for connections to the water and sewer utility system
which bases charges on estimated use. The graduated fee schedule
establishes additional costs for each 5,000 square feet of irrigated
lawn with lower fees established if a resident installs drip
irrigation or automatically timed spray irrigation.
In addition, Northglenn is also in the process of adopting a city
ordinance to specifically promote water conservation. This
recommended ordinance, entitled "Water Conservation and Plumbing Code
of 1979," specifies that:
"The Director of Natural Resources shall develop within 120
days of passage of this ordinance, an inventory list of
commercially available fixtures designed to achieve conservation
of water in an economically feasible manner. The inventory list
shall include, but not be limited to the following:
a. Indoor Criteria - Construction and Remodeling
1. Low flow toilets using less than 3.5 gallons per flush.
2. Air pressure toilets.
3. Shallow drip toilets.
4. Pressure reducing showerheads or water pressure valves.
5. Instant mixing thermostatic valve or similar device
reducing time for tap outflow to reach desired hot
water temperature.
6. Faucet aerators.
7. Self-regulating automatic shutoff faucets.
8. Dye table testing for toilet tank leaks.
9. Water conserving dishwashers.
10. Water conserving clothes washing machines.
11. Use of air cooled air conditioners.
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B. Outdoor Criteria - Construction, Remodeling and Landscaping
1. Landscaping - For grassy areas, exclusive use of
buffalo grass, western wheatgrass, crested wheatgrass,
blue gramma, a mix of these or other grasses, or a
comparable grass which will have the effect of
minimizing the consumptive use of water applied to such
grass or grasses for irrigation.
For non-grassy, non-food producing areas, use of plants
native to Colorado or states bordering Colorado.
2, Irrigation - In all cases in which the economic
character of the development proposal is such that
nonindigenous species of grasses, shrubs and trees are
to be utilized in the landscaping plan, provision shall
be made in the development proposal for an irrigating
system which incorporates only equipment of the most
water conserving type commercially available at the
time the proposal is submitted for approval. At a
minimum, irrigation systems shall:
a) be equipped with a time activated automatic
shutof f,
b) be equipped with sprinkler heads of a type which
provide the most uniform coverage feasible, and
maximum feasible droplet size to reduce
evaporation and wind disturbance of coverage,
c) where slope of the proposed development so
requires, irrigation systems shall be designed to
control flow for the purpose of reducing runoff
and increasing ground absorption.
3. Drainage Management - All development proposals shall
include a drainage management plan incorporating at a
minimum:
a) collection of runoff from roofs, patios,
sidewalks, driveways, streets and alleys.
b) application or diversion of the water collected
through 3(a) to the irrigation of landscaping
vegetation within the development or adjoining
developed land.
c) the design, construction and operation of
detention facilities shall conform to the
requirements of the Division Engineer in
accordance with the statutes of the State.
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4. Swimming Pools - All swimming pools, both new and
existing, shall be equipped with blanket pool covers
which shall be employed whenever the pool is not in
use."
Accordingly, EPA will impose a grant condition which states:
"Northglenn shall develop a water conservation policy similar to their
proposed ordinance entitled "Water Conservation and Plumbing Code of
1979, which encourages further reductions in wastewater flows. Said
ordinance with amendments shall remain in effect for the design life
of the project."
Radiological Emergency Response Plan
The City of Northglenn is located just beyond the area known as
the Category II area (10 mile radius) of the Rocky Flats Plant. The
proposed water supply system, however, includes Standley Lake and
Woman Creek which are inside the Category I area (5 mile radius).
Accordingly, EPA has determined Northglenn must comply with the
provisions of the Radiological Emergency Response Plan for Rocky Flats.
State officials will distribute a pamphlet telling those who live
within 10 miles of the Rocky Flats nuclear weapons plant what to do in
case of an emergency there. Its distribution, however, has been
stalled by two obstacles. First, state and federal officials can't
agree on what might be the worst case accident that could happen at
the plant, or what precautions should be taken. Second, a test of the
state's Disaster Emergency Services Agency revealed that the state
would find it difficult to carry out the emergency response outlined
in the plan.
Providing these steps are completed, Northglenn can implement the
recommendations of this plan that are applicable to their area. EPA
cannot currently impose a condition on Northglenn which is dependent
upon other agency actions outside the city's control. Therefore, with
respect to this plan, EPA will apply as a grant condition: "The
grantee shall develop a notification procedure consisting of
distributing and redistributing annually, a pamphlet notice yet to be
developed, approved, and furnished by the State, for notifying
existing homeowners within the Category II area as defined by the
State Radiological Emergency Response Plan. The grantee shall provide
EPA with a copy of the procedures, as adopted prior to receiving a
Step 3 grant from EPA, provided the State and the Department of Energy
have completed this pamphlet at that time. If and when the pamphlet
is formally approved at a later date, Northglenn shall then adopt and
maintain for the project design life, those procedures necessary for
the City of Northglenn as specified in the Radiological Emergency
Response Plan."
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Archaeolog ica1/His tor ica 1 Resource s
As noted in Appendix B, the survey of archaeological/historical
resources conducted of the proposed interceptor route and reservoir
site identified a possible area of interest consisting of a
turn-of-the-century dump along the interceptor route. No other
significant historical resources were identified. Northglenn
discussed the situation with the State Historic Preservation Officer
and has agreed to modify the interceptor route to avoid this area.
EPA will apply the following grant condition: "If archaeological or
cultural artifacts are unearthed, construction will be halted and the
State Historic Preservation Officer will be consulted immediately.
Accommodations will then be made as necessary for excavation and/or
assessment of uncovered archaeological resources."
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CHAPTER 6
EPA FUNDING CRITERIA AND ANALYSIS
-------
"The open society, the. unteAtsu.c.te.d
acceAA to knowledge, the. unplanned and
uninhibited (UAOcuttton OfJ men fioti
fiusvth&iance.—-t/ie^e &te lohat may make.
a va&t, complex, eueA g/towtng, eve/c.
changing, e.v&i mo fin ^pe-C^atczzd and
expert te.c,hnoŁogi.c.at wonJtd, ne.veAthe.-
a \tiontd oft human community."
J. Robert Oppenheimer
Science and the Common Understanding (1953)
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CHAPTER 6
EPA FUNDING CRITERIA AND ANALYSIS
EPA FUNDING CRITERIA
The 1977 amendments to P.L. 92-500 enunciate a major policy of
promoting the use of innovative and alternative waste management
techniques, with special focus on the municipal waste treatment
program. Though mentioned only briefly, innovative and alternative
technology was explicitly encouraged in the 1972 law. Few projects
applied such technology however, largely because of perceived greater
risks and higher costs on the part of the water quality
administrators, public health officers and consulting engineers.
Congress, therefore, used the 1977 amendments to require every
community seeking an EPA grant for construction of wastewater
treatment facilities to fully evaluate innovative and alternative
treatment options. Innovative and alternative techniques taken
together foster three central objectives: recycling and reuse of
water and waste materials, energy conservation and recovery, and cost
reduc tion.
Innovative refers to new and promising technology which is not
yet fully proven under the circumstances of its intended use. In
conventional treatment systems, innovative describes technology which
reduces life cycle costs by 15 percent or more, or reduces the amount
of energy required for waste treatment by at least 20 percent.
Innovative can also refer to new technology which advances the state
of waste treatment art.
Alternative technology is better known than innovative, offering
treatment approaches which are clearly alternative to conventional
secondary and advanced waste treatment processes. Included in this
category are such techniques as land treatment, aquifer recharge,
water reclamation and reuse, use of nutrients, direct industrial reuse
of effluents, composting and land application of sludge, and anaerobic
digestion of sludge to produce methane.
To encourage the use of innovative and alternative treatment
facilities, Congress provided, in the act, that such facilities be
funded at 85 percent of construction costs rather than the normal 75
percent. To provide funds for the increase, two percent (three
percent in fiscal year 1981) of construction grant funds allocated to
each state must be set aside for innovative and alternative
facilities, with at least one-half of one percent earmarked for
innovative facilities. This two percent set-aside is considered the
maximum amount that states may use to supplement the basic 75 percent
wastewater treatment works construction grant; therefore not all
projects proposing innovative or alternative technology will receive
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the ten percent supplemental grant. Single-purpose projects using
innovative or alternative techniques qualify for the 85 percent grant
if their life cycle cost under a cost-effectiveness analysis does not
exceed the life cycle cost of the most cost-effecitve conventional
alternatiave by more than 15 percent. Within two years from the date
of final inspection, EPA will pay 100 percent of the costs of
modifying or replacing any innovative or alternative treatment
facility which does not meet design performance standards and for
which correction of the failure requires significantly increased
capital or operation and maintenance costs.
EPA MULTIPLE-PURPOSE CONSTRUCTION GRANTS REQUIREMENTS
Generally EPA awards construction grant funds for wastewater
treatment works which are shown to result in the minimum total
resource cost over time and be adequate to meet Federal, State or
local requirements. A cost-effectiveness analysis is used to screen
different alternatives in order to determine the least-cost wastewater
treatment alternative. Should a municipality desire to undertake a
project that simultaneously performs a wastewater treatment function
and another function, EPA can participate in the funding under
multiple-purpose project funding criteria.
The current funding policy of EPA for the design and construction
of most types of multiple-purpose projects is stated in Program
Requirements Memorandum 77-4 (1). This memorandum enunciates the
Alternative Justifiable Expenditure (AJE) method for cost sharing; it
has been used since 1976, primarily in projects which involve combined
sewer overflow and urban drainage problems. The AJE method is founded
on the assumption that achieving multiple-purposes simultaneously
should be less costly than achieving them separately, and all purposes
should share in the cost savings. Thus, the funding for a project
under this policy is less than it would have been had the project been
designed for the single purpose of pollution control.
At the time the amount of funding for Northglenn was determined,
EPA was in the process of developing a method for funding
multiple-purpose projects which involve innovative and alternative
technology incentives as provided by the 1977 Clean Water Act
Amendments. In June of 1979 the Office of Water and Waste Management
of EPA distributed "Strategies for Funding of Multiple-Purpose
Projects"(2).
Seven alternatives were given for funding of multiple-purpose
projects.
1. Keep the status quo. Use the Alternative Justifiable
Expenditure (AJE) method for allocating costs, except for recreation
projects where the eligibility level is the same as the single-purpose
wastewater treatment project.
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2. Make all multiple-purpose projects eligible at the cost level
of the least costly conventional wastewater treatment single-purpose
projec t.
3. Make all innovative/alternative multiple-purpose projects
eligible at 115 percent of the single-purpose costs, and all
noninnovative/alternative projects at the single-purpose level. (The
actual rule in this option is somewhat more complex, employing a ratio
of the present worth costs of the single and multiple-purpose
projects.) This is the funding alternative selected by EPA for the
Northglenn project.
4. Use the same eligibility rules as option 3, except make
certain reclamation and reuse projects fully eligible—those in which
the reuse replaces existing water withdrawal and leaves water in the
stream which is required by a water-quality standard or a
water-quality management plan, for a guaranteed period of 20 years.
Expand the definition of "Enforceable Requirements of the Act" so as
to make these reclamation projects eligible for placement on the state
priority list.
5. Use the same eligibility rules as option 3, except that all
reclamation and reuse projects would be fully eligible. Revise the
priority system process so that the list is based on a ranking of all
surface and groundwater quality problems. Also, expand the definition
of enforceable requirements as in option 4.
6. Use the same eligibility rules as in option 5. Expand the
definition of enforceable requirements, and institute limits on the
proportion of state allotments which can be used to fund reclamation
and reuse projects.
7. Fully fund "integrated facilities" as defined in
Section 201(e) of the Clean Water Act, and all other multiple-purpose
projects at the level of the single-pur pose project.
It should be noted that the implementation of options 4 through 7
may require that a legislative change be made.
After the draft policy was issued in July 1979, EPA decided that
multiple-purpose projects using innovative/alternative technology
would be eligible for a grant based on option 3 as described above.
The latest direction by EPA after consultation with the public and
Congress is to retain the AJE method as described in option 1. EPA
used option 3 for funding the Northglenn project. Option 3 employs
this eligibility formula for innovative/alternative technology
projects: 115 percent of the ratio of (a) the present worth cost of
the most cost-effective single-purpose option, to (b) the present
worth cost of the multiple-purpose project, with a minimum eligibility
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of 115 percent of the capital cost of the single-purpose alternative.
This formula calculates the fraction of the multi-purpose project
costs which are eligible for EPA funding. Portions of a multi-purpose
project which involve innovative or alternative technology are
eligible for an 85 percent grant. Other portions are eligible for a
75 percent grant. This grant amount is therefore 85 percent or 75
percent of the fraction of the multi-purpose project cost that is
eligible. The extra 10 percent grant for innovative or alternative
wastewater treatment technology grants is taken from limited,
set-aside funds for each State. This money will be allocated at the
direction of the State.
Since the decision on the eligibility of the Northglenn project
was made, EPA has adopted the policy of funding new multiple-purpose
construction grant projects that involve innovative or alternative
technology under the Alternative Justifiable Expenditure (AJE) method
(3). Under the AJE method the amount of EPA construction grant
funding for the Northglenn project would be less than it would be
under the option 3 method. Based upon previous commitments, EPA will
use the option 3 method in order to determine the eligibility of the
Northglenn project.
For EPA to participate in the funding of a multiple-purpose
project, the following should apply:
1. The cost, of the multiple-purpose project must not exceed the
sum of the costs of the most cost-effective single-purpose options
which accomplish the same purposes.
2. The primary and secondary environmental effects must be
assessed in accordance with the NEPA review procedures, and the
project must not have any significant net adverse environmental
effects.
3. At least one of the purposes must be necessary to meet an
enforceable requirement of the Act.
4. There is no purchase of existing facilities with federal
funds.
5. The project meets the definition of treatment works, and the
works are publicly owned.
6. The project is consistent with the adopted and approved water
quality management plan.
7. For agricultural reuse projects a commitment to this use for
the design life of the project is necessary.
Northglenn meets all of these requirements (see Chapter 1 - EPA
decision).
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Application of EPA Funding to the NorthgJ.enn Project
The application of option 3 funding for Northglenn requires that
two costs be used, the present worth cost of the Northglenn
Multi-Purpose Project and the present worth cost of the most
cost-effective single purpose wastewater treatment alternative which
was determined to be continuing the conveyance of Northglenn's
wastewater to the Denver Metro wastewater treatment plant for
treatment.
Although at present the wastewater from the City of Northglenn is
treated at Denver Metro, there are costs associated with continuing
this alternative. Expansion of the secondary treatment capacity of
the treatment plant is necessary in order to enable the treatment
plant to continue to meet its present effluent limitations and treat
increased projected flows from the service area (2), In addition, the
Denver Metro discharge permit requires that the treatment plant be
upgraded to meet more stringent effluent requirements, including
nitrification of the effluent. Capital costs of the treatment of
Northglenn's flow at the Denver Metro facility were determined to be
the difference between the costs of building facilities that are
designed to handle the projected design year capacity with and without
the design flows from Northglenn. The operation and maintenance costs
of the treatment of Northglenn's flows at Denver Metro were determined
by the prorated fraction of the total operation and maintenance costs.
If Northglenn were to continue to have its wastewater treated at
Denver Metro for the 20-year planning period, the capacity of the
existing interceptor system which conveys Northglenn's flow to Denver
Metro would be exceeded (3). Costs were developed for an interceptor
and force main system that could accommodate the increased projected
flows. This system would serve Northglenn and part of Thornton. The
cost of this system that was attributed to Northglenn was a prorated
share of the capital and operation and maintenance (O&M) cost based
upon Northglenn's flow and the total flow.
For the purpose of calculating the EPA funding of the Northglenn
project, it has been determined that the multi-purpose project will be
considered to be a wastewater treatment and agricultural reuse
project. Therefore, portions of the Northglenn Water Resource
Management Plan, which involve domestic water treatment and
distribution, water supply, and urban runoff control, will not be
included as part of the cost of the project. The purchase of the
existing wastewater collection system by Northglenn was not considered
as a cost of the project in the analysis since it involved the
transfer of existing facilities between municipalities. The parts of
the project that shall be included are the costs of required
wastewater collection system changes, the conveyance of wastewater to
the treatment plant site, wastewater treatment, wastewater storage,
and measures taken to monitor and control potential adverse impacts of
the reuse plan.
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Shown in Table 6-1, the funding ratio for the Northglenn project
is calculated to be .67. The construction costs of the eligible
portions of the project were therefore multiplied by .67 to find the
eligible fraction of each item. EPA Construction Grant funds may then
be used to pay 75 percent or 85 percent of this eligible fraction.
EPA has determined that only the storage reservoir and the facilities
that are planned to monitor and mitigate impacts of the agricultural
reuse system are eligible for EPA funding at the 85 percent level
since these items relate directly to the alternative function of the
project - agricultural reuse. The extra 10 percent grant is taken
from limited funds that have been set aside for alternative wastewater
treatment technology projects which will be allocated by the State of
Colorado. It is therefore unclear at this time if this money will be
made available to Northglenn.
The Step 3 EPA Construction Grant estimate was determined to be
$6,948,000 if the alternative wastewater treatment technology funds
are allocated to Northglenn and $6,503,000 if the alternative
technology funds are not made available by the State.
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TABLE 6-1
GRANT ESTIMATE
Funding Ratio:
Costs of Treatment at Denver Metro +
Costs of Conveyance to Denver Metro
Cost of Northglenn Multi-Purpose Project
x 1.15
5,095,000 + 5,434,000
18,067,000
x 1.15 = .6702
Item
Treatment Lagoons
Storage Reservoir
Force Main
Pump Station A
Field Monitoring
Program
Dacono Disinfection
Firestone & Frederick
Tailwater Control
Cost
Estimate*
$3,450,700
6,361,100
2,139,500
712,600
77,500
32,500
Eligible
Fraction
(.6702X.75)
(.6702K.85)
(.6702X.75)
(.6702X.75)
(.6702X.85)
(.6702X.85)
75%
Grant
$1,734,494
3,197,407
1,075,420
358,188
38,955
16,336
Bonu s for
Alternative
Techno logy
$ 426,321
5,194
2,178
163,700 (.6702X.85)
82,284
10,971
$6,503,084 $ 445,654
TOTAL - $6,947,748 (rounded to $6,948,000)
*The actual cost will be the construction bid amount (see Appendix J for
further details of these cost estimates).
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CHAPTER 7
PUBLIC PARTICIPATION AND COORDINATION
-------
"Whateve/i an author. pat& between the.
couew o& hU> book Jut> public ptuop&uty; wb.cute.veSL
OjJ lujn&eŁ{l he. doz& not put theste. Jti> hi* private.
pfiopesity, a* much (u> i.^ he. had nevet wfutten a.
wold."
Gail Hamilton
Country Living and Country Thinking (1862)
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CHAPTER 7
PUBLIC PARTICIPATION AND COORDINATION
During preparation of this document several meetings have been
held to inform the public and solicit public comment. These meet-
ings have involved the public at large, vested interest groups, and
local and regional governmental entities. At the outset of the
project a discussion panel was established. The panel met offi-
cially in two public meetings and other informational meetings.
Participants on the advisory panel are listed below in Table 7-1.
The first public meeting was held August 30, 1979 and concentrated
on public health risks and direct impacts of the facilities. The
second public meeting on September 13, 1979, discussed the flow
augmentation plan and impacts on agriculture.
The following is a chronology of the public meetings held, and
a summary of the issues discussed during these meetings.
July 19, 1979 - EPA and Weld County citizens met in Frederick,
Colorado. EPA staff were shown problem areas in-
cluding Dacono's reservoir tailwater flow near
Frederick and asked to protect canal water quality
for drinking water use. EPA has determined that
it is necessary to require chlorination of Dacono's
nonpotable water supply, however, the canal need
not be protected as a drinking water supply source
(see EPA's decision in Chapter 1).
August 15, 1979-EPA and Consolidated Ditch met in Brighton, Colo-
rado. The meeting centered around Northglenn's
preliminary flow augmentation plan, how it may
effect South Platte water rights and South Platte
agriculture. Key issues discussed included: tri-
butary groundwater reductions; nitrogen concen-
trations; effects on sugar beets, barley, and
livestock; noxious weeds; and impacts to the
South Platte. These issues are discussed under
"Agricultural Issues" in Chapter 4.
August 28, 1979-EPA, State Health Department and Northglenn met
in Denver, Colorado. The purpose of this meeting
was to discuss grant eligibility, proposed permit
requirements and Northglenn's commitment to agri-
culture reuse. Key conclusion of this meeting
was that Northglenn owns sufficient land to ensure
an agricultural commitment. The issue of meeting
a 200/100 ml fecal coliform limit was discussed
and Northglenn has now agreed to meet this cri-
terion(see Chapter 5 on Steps to Minimize Adverse
Effects).
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August 30, 1979-Citizens Discussion Panel met in Frederick,
Colorado. Discussion at this meeting focused on
public health and direct impacts of the facili-
ties. It was concluded that significant public
health risks are associated with the plan as pro-
posed. A permit requirement of 200/100 ml fecal
coliform x.;ould reduce health risks and provide a
better degree of protection. Panel members dis-
cussed the following issues before the session was
opened to questions and answers from the floor:
Issue: Northglenn expressed a fear of setting precedent which
will impact all waters of the State.
Response: There are similar circumstances in the State where
secondary treated effluent is used for irrigated agri-
culture especially when low stream conditions exist.
However, under the Northglenn plan discharge of treated
effluent without any dilution from another source is
part of the day-to-day operational plan. EPA concludes
that additional measures are necessary for this unique
situation. Both EPA and the State of Colorado are
considering establishing uniform permit requirements for
uncontrolled agricultural reuse.
Issue: There is a lack of downstream monitoring to insure
compliance.
Response: Additional monitoring will be done by Northglenn in
order to understand the effects of the plant operation
(See Chapter 5 on "Additional Monitoring Requirements").
Issue: .Treatment process will not be able to control pathogens.
Response: Die-off of pathogens in lagoon systems is excellent.
(See Literature Review of Public Health Risks in Appendix C)
Issue: Hazards associated with a treatment plant upset during
peak irrigation season.
Response: Northglenn's operational plan must provide for this con-
tingency.
Issue: Effect of nutrients on fertilizer requirements and
groundwater.
Response: (See both the Agricultural Reuse Manual requirement and
Additional Monitoring Requirements in Chapter 5).
Issue: Panel members expressed concern over lack of advanced
information.
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Response: EPA has tried to accomodate all requests for informa-
tion as the information becomes available. EPA has
placed all public materials concerning the Northglenn
Project on reserve in EPA's library (See the Index
and Reference section).
Issue: The plan degrades Bull Canal water quality thus elimina-
ting it as a future water supply source.
Response: This is correct, see analysis on this issue in Chapter 4.
Issue: Complaint issued that treatment process operation has
not been evaluated.
Response: EPA intends to complete further analysis of the treatment
process during preparation of the final EIS.
Issue: Public health risks of Bull Canal tailwater in Frederick
and Firestone.
Response: A tailwater control plan is required (See
EPA decision in Chapter 1).
Issue: Stability and lining of Bull Canal reservoir.
Response: EPA will require additional construction measures to
reduce seepage (See Chapter 5).
Questions from the floor addressed the following topics:
Issue: Does the treatment process have the ability to meet the
BOD and suspended solids limit of 30-30 (BOD-SS)?
Response: Northglenn must comply with provisions under the State
issued NPDES permit to meet these limits. The proposed
treatment method is unique in using controls on alkali-
nity to meet these standards. EPA has conducted further
analysis of the treatment process and concludes suspended
solids concentrations could exceed permit limits.
Therefore, control of algal growth may be necessary.
Issue: Can FRICO farmers be restricted in the crops they choose
to grow and were cropping practices studied^
Response: Cropping practices were studied (See Agriculture in
the Study Area in Appendix G). Farmers are not restricted
in crop selection, however, Northglenn must advise
farmers regarding raw edible crops grown with their
effluent. (See Public Health Measures in Chapter 5.)
Issue: Why are there no EPA or State studies to develop viral
correlations to coliform counts ?
Response: Studies on the relationships of viral concentrations
to coliform bacteria have been conducted. However, pre-
sent data are inconclusive to establish any meaningful
correlations.
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Issue: What effect will industrial wastes have on water quality
and treatment processes'?
Response: See discussion on Heavy Metals and Industrial Pretreatment
Requirements in Chapter 4.
Issue: Is there an effect from nitrates on Ft. Lupton's future
water supply?
Response: No, see Use of Canal Water for Drinking Water Supply.
Issue: Will storage eliminate virus?
Response: No, but pathogens do die-off during storage, see Appendix C.
Issue: Will quality of water restrict farmers in irrigation prac-
tices?
Response: Changes in some irrigation practices will be necessary
See outline of Agricultural Reuse Manual in Chapter 5.
Issue: Northglenn will have to develop physical measures for
tailwater in Frederick and Firestone and irrigation water
in Dacono.
Response: Yes, see EPA's decision in Chapter 1.
Issue: Odor will create a problem in the surrounding area.
Response: Possibly, see analysis of odor problems in Chapter 4.
Issue: Treatment facility will not work as designed.
Response: See previous answer on this issue.
Issue: The potential for cross-contamination of vegetables.
Response: EPA believes the potential for cross-contamination of
vegetables does not create a health risk. Vegetables
irrigated with effluent are not to be sold commercially
and Northglenn's operational plans require a mode for edu-
cating farmers of appropriate precautionary measures
for private use.
Issue: Can Denver Metro handle Northglenn until 1985?
Response: Denver Metro must expand its facilities by 1985, see
EPA funding criteria in Chapter 6.
Issue: Who is responsible for enforcement of standards?
Response: The Colorado State Health Department.
-------
Issue: Who controls stopping discharge if water quality is
not suited for agriculture?
Response: EPA and Colorado State Health Department.
Issue: Is there going to be groundwater pollution under
canals?
Response: The Bull Canal will be lined by FRICO, see section on
"Canal Lining" in Chapter 4.
Issue: Will EPA address potential for canals to be used as
potable water supplies?
Response: EPA has determined such protection is unwarranted.
Issue: If Frederick were using the water as a domestic source
would there be a different determination as to protecting
this supply ?
Response: Yes, if a water source is currently used for any purpose
EPA is required to protect water quality for that use.
Issue: FRICO shareholders have not approved plan by a majority.
Response: The Board of FRICO has approved this plan.
Issue: The plan results in a loss of taxable income to Counties,
will impact local communities and is not consistent with
Weld County Land Use Plan.
Response: Tax loss is quantified in Chapter 4. The Weld County
Planning Commission has approved the treatment plant site.
Issue: The plan is not consistent with 208 plans, and conflict
in designating a Management Agency.
Response: See discussion on Management Agency designation in
Chapter 5.
Issue: Water lost from South Platte is a concern which may be
prevented if alternative water supplies besides Standley
Lake are evaluated. Project should be held up until
Water Court decision is made.
Response: EPA believes Water Court approval is likely with changes,
see Proposed EPA Decision.
Issue: Frederick's future water supply was discussed as to how
they intend to meet their requirement.
Response: EPA advises Frederick to seek an alternative water supply
other than the Bull Canal.
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Issue: What happens if Water Court requires more augmentation
water to implement plan?.
Response: Then Northglenn" must secure such water flows.
Issue: What water supply alternatives were evaluated?
Resp^ns"1: See Water Supply Alternatives in Chapter 3.
Issue: Can the concept of the augmentation plan be approved
by the Water Court?
Response: This must be resolved by the Water Court.
Issue: If groundwater is contaminated in wells near the reservoir
will Northglenn provide a new water supply?
Response: If such contamination is a result of Northglenn's
facility then presumably Northglenn would have to replace
these wells. EPA plans to require additional construction
requirements to further assure such a situation does not
occur, see Additional Measures to prevent groundwater
seepages in Chapter 5.
September 7, 1979 - EPA and Citizens Discussion Panel meeting in
Denver, Colorado. The purpose of this meeting was to
discuss with the panel issues of the plan and provide
additional information to the panel members.
September 11, 1979 - EPA and State 208 coordinator meet in Loveland,
Colorado. Primary discussion related to Management
Agency designation, See Chapter 5.
September 13, 1979 - Citizens Discussion Panel met in Northglenn,
Colorado. Discussion during this meeting focused on
the flow augmentation plan and agricultural impacts.
Several of the issues discussed during this meeting were
identified in the first Panel meeting. The new issues
and comments of this meeting are summarized below.
Issue: The flow augmentation plan appears to be viable but this
determination will be made in the Water Court.
Response: Correct, see EPA evaluation regarding protection
of vested water rights in Chapter 1.
Issue: There will not be any impact to sugar beets or barley
in FRICO.
Response: Proper management can prevent any problem, see discussion
on agriculture in Chapter 4.
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Issue: Concern was expressed about basing water supply on deep
wells. Can they be used only in dry years?
Response: See alternative water supply options in Chapter 3.
Issue: The plan protects agriculture, does not impact ground-
water in the South Platte valley, Northglenn will
develop plans to protect public health.
Response: No response necessary.
Issue: Green corn with high nitrate concentration will be toxic
to cattle. How will they be protected?
Response: Proper drying of silage corn prevents this problem. See
discussion on water quality in Chapter 4.
Issue: Energy may be saved by using fertilizer benefit of
wastewater to reduce purchase of chemical fertilizer.
Response: Some energy costs will be reduced by recycling nutrients.
Issue: Industry will require pretreatment prior to treatment at
facility.
Response: Correct, see disscusion on this issue in Chapter 4.
Issue: Advisory Panel is supposed to have technical advisory
group.
Response: Not necessarily, EPA believes the Panel provided valuable
recommendations which are reflected in EPA's decision.
Issue: Federal money should help provide additional storage
of Colorado water.
Response: Not related to EPA mission.
Issue: Big Thompson water for Frederick is too expensive.
Response: Frederick needs to find the least-cost solution to their
needs.
Issue: Agricultural impacts are - shifting agricultural water,
drying up agricultural land, creating salt problem in
soil, dust bowl effect, shallow wells not protected,
not consistent with Governor's wishes to protect farms,
noxious weeds, tax losses, nitrogen on crops, livestock
and groundwater.
Response: See analysis in Chapter 4 regarding these issues.
143
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Issue: Need another meeting to address Interagency agreements
and input to consultants.
Response: EPA will require Northglenn and Weld County to execute
an Intergovernmental agreement prior to grant award,
See Chapter 5.
October 2, 1979 - EPA met with opponents of Plan in Loveland,
Colorado. A list of requirements for the Intergovern-
mental agreement was presented and is discussed under
the Management Agency Designation section in Chapter 5.
October 12, 1979 - EPA tours project area and meets with citizens
near Frederick. Tailwater control, chlorination at
Dacono and groundwater contamination were discussed.
A new issue raised was whether a proposed coal strip
mine by Coors would create potential for groundwater
contamination. This issue will be addressed by the
Office of Surface Mining, Department of Interior should
Coors submit a mining plan.
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TABLE 7-1
NORTHGLENN DISCUSSION PANEL
NAME
Western Wilson
Dick Lundahl
Frank Culkins
REPRESENTING
EPA, Panel Moderator
City of Northglenn
Weisner Subdivision
Bill Schuler
Adolph Bolander
Elton Miller
Ray McNeil (Dick Johnson)
John Hall
John Kemp
Bob Doyle
John Rutstein
Tess McNulty
Michael Richen (John Bermingham)
Jerry Armstrong
Town of Frederick
Farmers Reservoir and
Irrigation Company
Consolidated Ditch Company
Denver Metro
Weld County Health Department
Adams County
Denver Regional Council
of Governments
Larimer-Weld Council of
Governments
Colorado League of Women
Voters
Colorado Open Space
Council
Rocky Mountain Fuel Company
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PUBLIC REVIEW OF DRAFT EIS
On January 11, 1980 EPA distributed for public review and comment the
Draft Environmental Impact Statement of the Northglenn Water Management
Program. A public hearing was held on February 13, 1980 to receive comments
on the draft report. A summary of the public hearing, written comments
received on the draft environmental impact statement, and EPA's response
to the public hearing and comments are presented in Appendix A.
146
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CHAPTER 8
LIST OF PREPARERS
Environmental Protection Agency
Weston W. Wilson - Project Officer - Environment al Engineer
B.S. in Geological Engineering and M.S. in Water Resources
Administration from the University of Arizona, Tucson, Arizona.
Five years experience with EPA as project officer for environ-
mental impact statements for wastewater treatment facilities
including Steamboat Springs, Colorado, and Jackson Hole,
Wyoming. Special emphasis has been on land application of
effluent, investigation of water rights, protection of environ-
mentally sensitive areas and federal-state-local government
agreements. Preparation of numerous EPA reports including water
quality analyses, mined land reclamation reviews, power plant
sitings and dredge and fill permits. Worked as EPA's consul-
tant for the preparation of the President's National Water
Policy.
William Rothenmeyer - Sanitary Engineer
B.S. in Civil Engineering at Rensselaer Polytechnic Institute
in Troy, New York. Graduate level study at University of
Colorado at Denver in Civil Engineering. Three and one half
years experience with EPA in Regions II and VIII involved with
permits and construction grants for municipal wastewater treat-
ment facilities .
Engineering Science
Paul N. Seeley - ZLL^^JLJ^JIM?.!-^
B.A. in Environmental Biology, University of Colorado. Seven years
experience in water quality monitoring, water resource planning
environmental assessment, aquatic and terrestrial ecology,
evaluation of land application, and impact analysis for a
variety of wastewater treatment and disposal projects.
Allan L. Udin - Sanitary Engineer
B.S. and M.S. in Civil Engineering from Montana State University.
Fifteen years experience in water and wastewater treatment
facility planning, design, and operation. Projects have in-
cluded water treatment and storage facilities, water transmission
lines, water master plans, wastewater facilities plans, design
of conventional and advanced wastewater treatment facilities,
and plant operations consulting.
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Richard L. Elton - Sanitary and Chemical Engineer
B.S. and M.S. in Chemical Engineering from University of Texas.
Nine years experience in wastewater treatment facility planning,
design and operation. Projects have included municipal and industrial
wastewater treatment and solid waste management systems, wastewater
characterization pilot - scale treatability tests, and conceptual
designs of facilities.
Earnest F. Gloyna, Ph.D. - Special Consultant
Dr. Earnest F. Gloyna, P.E. is dean of the College of Engineering at
the University of Texas at Austin. He holds the Joe J. King Professor-
ship. He is a registered professional engineer in the State of Texas.
He received his BS degree in civil engineering from Texas Technological
College, 1946; MS degree in civil (environmental) engineering from the
University of Texas at Austin, 1949; and Doctor of Engineering degree
in environmental and water-resources engineering from the Johns Hopkins
University, 1952. Dr. Gloyna is author of two books in the field of
environmental engineering, including one on Radiological Health, editor
of five books in water resources and wastewater treatment. He has
chaired several major committees and panels for the U.S. National
Academy of Sciences and the National Academy of Engineering, including
Committee on Radioactive Waste Management, Ocean Disposal, Environmental
Manpower Planning and Waste Management. In addition, he is author of
140 professional papers on industrial wastewater management, water reuse,
radiation protection, environmental health engineering and engineering
education. He recently served on the Executive Committee and Director
of the Water Pollution Control Federation. Dr. Gloyna has served as
consultant or advisor to numerous U.S. governmental agencies, cities,
and industries; to the United Nations and the World Health Organization;
the World Bank; and various foreign governments and cities.
Raymond L. Anderson, Ph.D. - Special Consultant
Dr. Raymond L. Anderson is a resource economist with the Economic
Research Service of the U.S. Department of Agriculture working at
Colorado State University, Fort Collins, Colorado. He has been
extensively involved in water resource management, and economic
management of irrigation systems. He has authored more than forty
publications dealing with various aspects of irrigation water use and
land resources.
Bishop Associates
Harold F. Bishop - President
B.S. Civil Engineering University of Utah. Responsible for investi-
gation and design of water resource projects, including detailed
investigations of water rights, irrigation requirements, design of
drainage facilities and hydraulic structures, feasibility reports
and flood studies. He has served as Project Engineer on numerous
water rights studies and has testified as an expert witness on water
matters in various water courts in Colorado and in Jefferson County
District Court. Over 50 percent of his work has been with water
rights and consulting services to irrigation ditch companies.
150
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Tipton and Kalmbach
Clinton W. Mehring - President
Mr. Mehring has an M.S. in Civil Engineering University of Colorado.
Project experience includes design and structural analysis of canals,
dams, and tunnels, preparation of feasibility studies, designs,
specifications, and supervision of construction for numerous water
resource projects throughout the world.
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/ V
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CHAPTER 9
REFERENCES
CHAPTER 2
1. CH2M Hill, Water Diversion and Treatment Reconnaissance Study.
2. City of Thornton. Utilities Department Annual Report, 1978.
3. Personal communication, Gary Palmer, Director of Utilities.
Thornton, Colorado, October 5, 1979.
4. FRICO - Northglenn Agreement, September 2, 1976.
CHAPTER 3
1. City of Northglenn. Application for Site Approval - Northglenn/FRICO
Return Flow Facility. Submitted to the Colorado Water Quality Control
Commission. March 19, 1979.
2. Wright Water Engineers, Inc. Environmental Study Addendum East Slope
Alternatives Review. March 21, 1980.
CHAPTER 4
1. U. S. Army Corps of Engineers and U. S. Environmental Protection
Agency, Process Design Manual for Land Treatment of Municipal
Wastewater.
2. U. S. Environmental Protection Agency, EPA Policy on Land Treatment
of Municipal Wastewater, October 3, 1977
3. Colorado Department of Health. Memorandum on Interim Division
Guidance on Planning and Design Review for Land Application
Systems, March 18, 1977.
4. Sheaffer and Roland, Wastewater Facilities Northglenn, Colorado,
Volume 3, April 25, 1977.
5. Sheaffer and Roland, 201 Wastewater Facilities Plan, Volume 4,
August 24, 1977.
6. Northglenn - Thornton Agreement, May 4, 1979.
7. U. S. Environmental Protection Agency. EPA Policy to Protect
Environmentally Significant Agricultural Land, September 8, 1978.
8. Wright Mclaughlin, Northglenn Water Management Program,
Volumes 1 and 2. April 20, 1977.
9. Wright Water Engineers - City of Northglenn South Platte
Augmentation Plan Engineering Report, March 31, 1980.
10. Personal communication. Cheryl Signs, City of Westminster.
August 1979.
153
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11. Hydro Triad Ltd. Engineers, Review of Northglenn/FRICO Land
and Water Resource Management Report, April, 1977.
12. Wright Water Engineers, Interim Report on Seepage Studies,
September 5, 1978.
13. Personal communication, Robert McGregor, Sheaffer and Roland,
August 1979.
14. Wright Water Engineers, Report on Operation of Standley Lake,
September 1979.
15. Personal communication, Wright Water Engineers, August 1979.
16. Colorado Department of Health, Water Quality Control Commission,
Regulations Establishing Basin Standards and an Antidegradation
Standard and Establishing a System for Classifying State Waters,
for Assigning Standards, and for Granting Temporary Modifications.
Adopted May 22, 1979, Effective July 10, 1979.
17. Water Quality for Agriculture, FAO Irrigation and Drainage Paper
No. 29.
18. Chen and Associates, Inc. Preliminary Engineering Geology and
Soils Investigation for a Proposed Reservoir. Sections 26 and
36, T.1N., R.68W. Weld County, Denver, Colorado, March, 1978.
19. Chen and Associates, Inc. Subsurface and Geological Investigations
for a Proposed Reservoir Site Weld County, Colorado, Denver,
Colorado, September, 1978.
20. Four-way Agreement, May 9, 1979.
21. Wright Water Engineers, Interim Letter Report on Seepage Losses
September 5, 1978.
22. Personal communication, Ron Halley, Hydro-Triad, August, 1979.
23. Personal communication, Wright Water Engineers, August, 1979.
24. Whittlesey, Norman K., Irrigation Development Potential in
Colorado. Environmental Resources Center, Colorado State
University, May 1977.
25. Personal communication with Boulder County Realtors and Land
Appraisers.
26. Personal communication, Ralph Mock, Chen and Associates, October 29,
1979.
27. Davis, C. V., and K. E. Sorensen. Handbook of Applied Hydraulics,
Third Edition, 1969.
28. U. S. Bureau of Reclamation, Earth Manual, Second Edition,
U. S. Department of the Interior, 1974.
154
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29. Mostertam, L. J. Waves of Long and Short Period in Selected
Aspects of Hydraulic Engineering, Technological University of
Delft, The Netherlands.
30. Colorado Department of Health, Air Pollution Control Commission,
Regulation 2, Odor Emission Regulations, 5CCR 1001-4 Adopted,
March 11, 1971, Effective: April 20, 1971.
31. Turner, D. B., Workbook of Atmospheric Dispersion Estimates.
Environmental Protection Agency, Research Triangle Park, N.C.,
1970.
32. Ugo, Coty. The Challenge of Wind Energy, Lockheed-Gal Company,
Burbank, California.
33. Personal communication, Climatological Center, Colorado State
University, August, 1979.
CHAPTER 6
1. U. S. EPA, Funding Policy for Design and Construction-Multiple-Purpose
Projects, PRM 77-4.
2. U. S. Environmental Protection Agency, Strategies for Funding of
Multiple-Purpose Projects, Office of Water and Waste Management,
June 1979.
3. Longest, Henry L. Ill, "Draft PRM Regarding Procedures for Determining
Grant Eligibility for Multiple-Purpose Projects." Office of Water and
Waste Management USEPA Washington, D. C., March 20, 1980.
155
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INDEX
ADAMS COUNTY il, 14, 26, 28, 76, 88, 109, 110, 11, 115, 147
AESTHETICS AND VISUAL EFFECTS 11, 88, 90, 91
AIR QUALITY 80, 100, 113, 114, 116, 117, 118, 119, 120
ALTERNATIVE TECHNOLOGY iii, 7, 12, 129, 130, 131, 132, 134, 135
ARAPAHOE FORMATION 54, 106
ARCHAEOLOGY 100, 114, 126
AUGMENTATION PLAN iv, 6, 10, 18, 21, 24, 54, 57, 58, 59, 61, 62, 63, 102,
139, 144
BACTERIA 7, 8, 43, 48, 50, 141
BARLEY 10, 53, 70, 139, 144
3ERTHOUD CANAL (BERTHOUD PASS DITCH) 23, 58, 60
BIG DRY CREEK 26, 28, 56, 57, 75, 76
BULL CANAL 5, 7, 8, 10, 12, 26, 27, 28, 29, 35, 48, 49, 53, 56, 57, 61, 62,
68, 69, 70, 74, 75, 76, 82, 85, 86, 99, 100, 101, 102, 103, 111,
141, 143
BULL CANAL RESERVOIR 5, 47, 57, 58, 103, 104, 141
BURLINGTON DITCH 33, 34, 58
CHLORINATION 5, 7, 8, 17, 47, 49, 50, 68, 86, 101, 111, 139, 146
CHURCH DITCH 58, 60
CLEAR CREEK 22, 33, 34, 35, 56, 57, 58, 59
COLORADO DEPARTMENT OF HEALTH 8, 40, 49, 50, 99, 111, 139, 142, 143
CONSOLIDATED DITCHED (i.e. Lower South Platte Ditches) 139, 147
CORN AND SILAGE 73, 145
156
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CROKE CANAL 56, 57, 61
DACONO 8, 26, 40, 48, 100, 101, 102, 11, 113, 135, 139, 142, 146
DENVER iii, 17, 30, 32, 33, 34, 77, 80, 89, 109, 110, 113, 114, 117
118, 119, 120, 122, 139, 144, 147
DENVER WATER BOARD 6, 14, 32, 33, 35, 36, 37, 38
DISEASE 8, 47, 48, 49, 101
DISINFECTION 8, 40, 68, 100, 101, 102, 111, 113, 135
EARTHQUAKE 77
EDIBLE FOOD CROPS 6, 8, 9, 48, 49, 68, 102, 103, 111, 141
ENERGY CONSERVATION 100, 114, 122, 129
ENGINEERING SCIENCE, INC. iii, 151, 164
FARMERS RESERVOIR AND IRRIGATION COMPANY (FRICO) iv, 3, 4, 5, 9, 10, 18, 21,
22, 23, 24, 25, 30, 32, 34, 35, 36, 38, 47, 48, 50, 53, 54, 56, 57, 59, 60,
61, 62, 63, 65, 66, 69, 75, 103, 104, 105, 141, 143, 144, 147
FARMERS HIGHLINE CANAL 23, 58, 60
FAULTS 11, 29, 74, 75, 105, 106
FECAL COLIFORM 7, 8, 47, 48, 49, 50, 101, 113, 139, 140, 141
FIRESTONE 7, 48, 102, 111, 135 141, 142
FORT LUPTON 12, 69, 142
FREDERICK 7, 12, 26, 48, 69, 102, 111, 135, 139, 140, 141, 142, 143, 145,
146, 147
GRANGE HALL CREEK 22, 23, 24, 54, 58, 59, 60
GRANT CONDITIONS 6, 8, 9, 40, 81, 99, 101, 102, 103, 104, 105, 106, 110, 112,
118, 119, 121, 125, 126
157
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HEALTH RISK (HEALTH HAZARDS) 8, 43, 47, 48, 49, 50, 51, 68, 99, 100, 101,
139, 140, 141, 142
HEAVY METALS 50, 51, 72, 73, 106, 112, 142
cadmium selenium zinc vanadium maganese chromium
lead plutonium copper mercury molybdenum
HYDRO-TRIAD INC. 75
INTERGOVERNMENTAL AGREEMENT 13, 14, 108, 109, 113, 146
LAKAMIE-FOX HILLS FORMATION 54
MANAGEMENT AGENCY 100, 107, 108, 109, 110, 112, 143, 144, 146
NITRATES 3, 10, 12, 17, 43, 46, 53, 68, 69, 70, 72, 73, 75, 85, 86, 87, 103,
133, 139, 142, 145
nitrogen
nitrate
nitr ification
ODOR 6, 11, 45, 80, 81, 83, 85, 142
PATHOGENS 8, 48, 49, 50, 106, 112, 140, 142
PERMITS ii, 3, 7, 9, 13, 14, 40, 47, 50, 81, 99, 100, 101, 102, 107, 108,
116, 120, 133, 139, 140, 141
]
RADIOLOGICAL IMPACTS 79, 100, 114, 125
ROCKY FLATS PLANT 79, .125
SAFETY 11, 25, 77
SAND HILL LAKE 12, 69
SCHAEFFER AND ROLAND, INC. 86
SEEPAGE 25, 59, 61, 73, 74, 75, 76, 78, 100 105, 106, 112, 141, 144
SOIL CLASSIFICATIONS
158
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SOUTH PLATTE RIVER iv, 3, 4, 5, 9, 10, 21, 22, 25, 32, 33, 34, 35, 36, 53,
54, 57, 58, 50, 62, 64, 65, 66, 69, 76, 83, 89, 139, 143, 145
STANDLEY LAKE iv, 4, 10, 18, 21, 22, 23, 25, 48, 52, 56, 57, 60, 61, 62, 63,
64, 75, 76, 79, 102, 103, 104, 105, 125, 143
STATE ENGINEER 3, 9, 10, 11, 22, 54, 58, 62, 74
TAILWATER 7, 8, 40, 48, 69, 100, 102, 106, 111, 112, 135, 139, 142, 146
TAXES 11, 76, 88, 113, 143, 145
TIPTON AND KAL3ACH, INC. iii 152
THORNTON 3, 4, 6, 14, 17, 18, 23, 24, 25, 32, 33, 34, 35, 36, 37, 50, 51, 52,
56, 59, 60, 75, 115, 133
URBAN RUNOFF iii-iv, 3, 4, 5, 6, 21, 100, 113, 120, 121, 133
VIRUS 141, 142
WATER CONSERVATION 6, 114, 122, 123, 125
WATER COURT 4, 6, 9, 10, 18, 24, 33, 34, 54, 57, 58, 59, 62, 102, 143, 144
WATER RIGHTS 4, 6, 10, 21, 22, 23, 25, 30, 31, 32, 33, 34, 35, 36, 54, 57,
58, 59, 61, 62, 76, 102, 105, 139, 144
WEEDS 88, 139, 145
WEISER SUBDIVISION 82, 84, 85, 88, 90, 92, 93, 147
WELD COUNTY iv, 4, 5, 11, 13, 14, 21, 26, 28, 76, 82, 88, 94, 95, 107, 108,
110, 111, 113, 139, 143, 146, 147
WESTMINSTER 17, 18, 56, 75
WOMAN CREEK 79- 125
WRIGHT WATER ENGINEERS 54, 55, 64, 75, 76
159
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-908/5-5-79-002B
2.
3. RECIPIENT'S ACCESSION NO.
A. TITLE AND SUBTITLE
Final Environmental Impact Statement
Northglenn Water Management Program
City of Northglenn, Colorado
5. REPORT DATE
June 27, 1980
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
Weston W. Wilson and William Rothenmeyer, EPA
Al Udin and Paul Seeley, Engineering Science, Inc.
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Engineering Science, Inc.
2785 North Speer Blvd., Suite 140
Denver, Colorado 80211
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
12, SPONSORING AGENCY NAME AND ADDRESS
U.S. Environmental Protection Agency
Region VIII
1860 Lincoln Street
Denver, Colorado
13. TYPE OF REPORT AND PERIOD COVERED
Final
14. SPONSORING AGENC CODE
15. SUPPLEMENTARY NOTES
Environmental Appraisal and Negative Declaration dated September 29, 1978, issued by
EPA. Draft Environmental Impact Statement dated January 11, 1980 also issued by EPA.
16. ABSTRACT
This is a final Environmental Impact Statement (EIS) for proposed construction of
facilities to provide water supply, wastewater treatment and agriculture reuse of
sewage effluent for the City of Northglenn, Colorado. Under an exchange anreement
with the Farmers Reservoir and Irrigation Company, approximately 5,000 acre-feet
annually will be diverted for Northglenn's municipal use, treated, augmented from
other sources, stored, and then returned for irrigation purposes.
The U.S. Environmental Protection Agency (EPA), Region VIII, Denver, under the
authority of Section 201 of the Federal Water Pollution Control Act Amendments of
1972, is authorized to grant 75 and up to 85 percent matching funds for construction
costs of designated wastewater treatment facilities.
The recommended action is to construct an 8 mile interceptor, aerated lagoon and
a storage reservoir. Implementation of the exchange program negates the pending
water condemnation actions that are in progress.
The appendix includes responses by EPA to comments recieved on the draft EIS,
analysis of the alternative systems and cost estimates.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS
c. COSATI Field/Group
Wastewater Reclamation
Sewage Irrigation
Agricultural Reuse
Water Pollution
Flow Augmentation Plan
Alternative Wastewater Treatment Techrrolog.
Environmental Impact Statement
Denver Regional EIS for
Wastewater Facilities
and the Clean Water
Program
Denver Metro Sewage
Farmers Reservoir and
Irrigation Company
18. DISTRIBUTION STATEMENT
Release Unlimited
19. SECURITY CLASS (This Report)
21. NO. OF PAGES
20. SECURITY CLASS (This page)
22. PRICE
164
EPA Form 2220-1 (Rev. 4-77)
PREVIOUS EDITION IS OBSOLETE
164
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NOTE
Excess woier over repayment requirement
available under overage year conditions
-------
NOTE
Excess water over repayment requirement
TAL SERVICE AREA - 15,000 ACRES
ANNUAL IRRIGATED AREA- 7,OOO-S,OOO ACRES
11970-19781
d upon I9B6 development conditions
ENVIRONMENTAL PROTECTION AGENCY
NORTHGLENN/FRICO WATER MANAGEMENT PROGRAM
OPTION NO. 2
(65O A.F. FROM DEEP WELLS)
-------
—-Yield to Ncrthglenn under
drY year and overage yea
conditions in acre feet
NOTES
>d upon 1938 development conditions
NORTHGLENN/FRICO WATER MANAGEMENT PROGRAM
OPTION NO. 3
(230O A.F. FROM DEEP WELLS)
-------
— -riela Jo Nonhglenn una
dry year and average year
ENVIRONMENTAL PROTECTION AGENCY
NORTHGLENN/FRICO WATER MANAGEMENT PROGRAM
OPTION NO. 4
(RETURN TO METRO)
U. S. GOVERNMENT PRINTING OFFICE 1980 - 678-895/M6 Reg 8
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