United States
Environmental Protection
Agency
Region 8
1860 Lincoln Street
Denver, Colorado 80295
v>EPA Record of Decision
EPA 908/5-79-002E?
September 1980
Northglenn Water Management Program
City of NorthgSenn, Colorado
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749315/
EPA - 908/5-79-002D
RECORD OF DECISION
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 by>
' Rojfcr LV,Williams
jgior&T Administrator
Date:
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TABLE OF CONTENTS
Record of Decision
Northglenn Water Management Program
Northglenn, Colorado
Page
Scope of Decision 1
Alternatives Including the Proposed Plan
Descriptions of Options Within the Plan 2
Wastewater Treatment Alternatives 3
Treatment Site Alternatives 3
Water Supply Alternatives 7
No Federal Action Alternative 9
Discussion of the Environmentally Preferred Alternative 15
EPA Decision 17
Steps to Minimize Adverse Effects 25
NPDES Permit Conditions 25
EPA Grant Conditions 27
Response to Comments Received on the Final EIS 35
Agricultural Productivity 35
Canal Lining and the Flow Augmentation Plan 36
Tailwater Control 39
Intergovernmental Agreement with Weld County 40
Reduction in Residential Property Values 40
Analysis of Recreational Potential 40
Provisions of the Clean Air Act 41
Cost Analysis for the South Platte-Deep Well Alternative 41
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RECORD OF DECISION .
Scope of Decision" ;.
This Record of Decision has been prepared in accordance with Che
regulations of the Council on Environmental Quality (CEQ) and the
Environmental Protection Agency (EPA) for implementing the National Environ-
mental Policy Act (NEPA) (40 CFR, Parts 1500-1508, dated November 29, 1978.)
The National Environmental Policy Act requires that Federal agencies con-
sider environmental factors and alternatives in their decision-making process.
Section 102(2)(c) of NEPA establishes procedures for preparation of Environ-
mental Impact Statements (EISs) for Federally-funded projects which have the
potential to "significantly affect the quality of the human environment". The
scope of this record of decision includes all of the information and analysis
contained or referenced in the draft EIS, final EIS, public hearing records,
and public comment letters related to the Northglenn project.
Background
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 EPA has approved a facility plan for the
proposed project and performed an anlysis 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 agricultural water rights from the South Platte River
following denial by the State Engineer of permits for nontributary deep
wells. On June 27, 1980 EPA issued the Final EIS analyzing the environmental
impacts of the Northglenn Plan.
ALTERNATIVES INCLUDING THE PROPOSED PLAN
Description of the Northglenn Water Management Plan (Proposed 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.
Northglenn has entered into a water exchange agreement with The Farmers
Reservoir and Irrigaton 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. Northglenn proposes
to construct a year-round storage reservoir in Weld County adjacent to its
proposed wastewater treatment facility. Satisfying the payback requires the
development of a means of replacing the water borrowed by the City plus
10 percent. This plan for the water payback 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 and other water rights intended for
developmental purposes.
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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 with
each property owner in Northglenn which will expire in 1988. Consequently,
Northglenn has negotiated an agreement with Thornton whereby Northglenn's
wastewater treatment will be provided by Northglenn. Northglenn's revised
facility plan makes the following recommendations for wastewater trans-
port, treatment, and disposal:
Collection System - Northglenn will make improvements to the
existing collection system which include sealing off several
lines and connecting them to a new interceptor.
Conveyance System - 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.
Wastewater Treatment - The proposal is to construct an
aerated, three cell lagoon system for treatment prior
to storage and discharge.
Storage and Disposal - A 4362 acre-foot reservoir (Bull Canal
Reservoir) will be constructed in Weld County to provide for
winter storage of the effluent. 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. Chlor-
ination of the effluent will occur just prior to discharge from
the storage reservoir to the Bull Canal irrigation ditch.
Sludge Disposal - Sludge will be removed and injected in the
surrounding agricultural land.
Description of Options Within the Plan
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 - Northglenn obtains South Platte surface water
rights currently used for irrigation.
Option 2 - Northglenn is awarded 650 acre-feet per year
of nontributary groundwater, thereby reducing
the amount of South Platte surface water
rights needed.
Option 3- - Northglenn is awarded 2300 acre-feet per year of
nontributary groundwater thereby eliminating
the need for South Platte surface water rights.
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•Option 4 - 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.
Wastewater 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 treatment
continued at Denver Metro.
Northglenn's proposed wastewater treatment facility has been described
previously. Treatment at Denver Metro could be compatible with all water
supply alternatives considered with the exception of the FRICO exchange
agreement.
At present the wastewater from the City of Northglenn is treated at the
Denver Metro Treatment Plant. 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. In addition, the Denver Metro
discharge permit requires that the treatment plant be upgraded to meet more
stringent effluent requirements, including nitrificiation 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 wastewa£er 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 through
Thornton (Northglenn is not a member of Metro) would be exceeded. Costs were
also 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. The cost of these two alternatives
for wastewater treatment are presented in Table 1.
Treatment Site Alternatives
EPA conducted an alternative site analysis for a wastewater treatment and
storage system, which would be similar 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. The site analysis
evaluated three additional sites for treatment and storage of Northglenn's
wastewater (see Figure 1).
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TABLE 1
WASTEWATER TREATMENT
NORTHGLENN TREATMENT AND RETURN TO FRICO
. ITEM
Treatment Lagoons
Bull Canal Reservoir
Pump Sta. "A"
Force Main
Collection System
Field Monitoring
Dacono Disinfection
,
Tallwater Control
Maintenance Equipment
Construction Manager
Land & Easements
Contingencies
Engineering
Step 3 Engineering
Sub-Total
EPA Funding
TOTAL
Capital Costs
$ 2,643,100
4.354,700
597,800
1,729,000
10.151,100
57.400
20.000
110.200
150.000
429.700
,
161,400
1.082,570
2.212.600
513,000
24,212,600
6,948,000
$ 17,264,600
O&M
$ 260.800
86,000
32,190
14,430
98,160
35,100
1.600
1.500
0
0
0
0
0
0
529.780
0
$ 529,780
Salvage
$ 439,651
724,357
49,719
287.600
510.254
0
0
Land
72,000
f 0
0
0
180.074
0
0
2.198,855
0
$2.198.855
METRO DENVER TREATMENT
Item
Denver Expansion
So. Platte 15" Interceptor
Henderson Pump Station
Henderson Force Main
Washington Pump Station
Collection (Northglenn)
(Thornton)
Contingencies
Engineering'
Debt Service Existing
TOTAL
Capital Less
O&M (661,099
Capital
$ 662,679
670,312
866.700
1.847.376
49.819
546,800
8,991,900
900,777
501,400
$ 15.037,263
PRESENT WORTH
Thornton Pipes
Thornton Pipes
Sub-total
x 10.694644)
Salvage Value
Total P.W.
Annual Worth
llnlr C.nat
O&M
$ 383.389
21,400
18.100
300
97,900
0
0
88,800
$ 661,099
$ 6,045
7,991
14.037
7.070
(1,437
19.690
$ 1,839
1.41
Salvage
$ 66.822
132,973
85,966
366,473
0
71,594
713.507
Contained with-
•alvage value
0
$ 1.437.335
,863
,400
,763
,218
,335)
.146
,300 $/Yr.
S/1000 sal.
PRESENT WORTH
Capital Less Thornton Pipes
Thornton Pipes
Sub-total
O&M (529,780 x 10.694644)
Salvage Value
Total P.W.
Annual Worth
Unit Cost
4016 AF/Yr. from Northglenn
Average Household
74x3x365
4016 AF/Yr. fron Northglenn
Average household
74x3x365
114 $/Yr.
$ 8,273,200
7,991,400
16,264.600
5,665.808
<2,198,855>
19,731,553
1,844,944 $/yr.
1.41 $/1000 gal.
114 $/yr.
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FIGURE 1
LEGEND
2J1 STUDY AREA BOUNDARY
^ PROPOSED SITE
II ALTERNATIVE SITES
RESIDENTIAL DEVELOPMENT
~MAJOR ROADS
...-WATERWAYS
Weld County
ALTERNATIVE SITE
STUDY AREA
N
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TABLE 2
ENVIRONMENTAL EVALUATION MATRIX OF ALTERNATIVE TREATMENT AND STORAGE SITES
CRITERION
SITE A
SITE B
SITE C
SITE 10
ijfology
Mineral Resources
Poult*
Suhftldr nee
Soils
Permeability
Suitability for Construction
Prime Agriculture Land
Tnpoftraphy,
Slop*
Flooding Potential
(>roundwater
Hcpth
Number of iells Onaltt .
L.ind Use
Current
Zoning
No. of Residences
Pronlmltv to Bull Canal
co.t y
No aand or gravel resources.
No active or potentially
active faults
Probably not of concern:
South of Boulder -
Weld Coal Field
Low pern., 0.06 - 20 in/hr
Hed. to low shear strength
Mod. to high ahrlnk-awell pot.
Yea - if irrigated
East half 3-5X slope to east
West half 0-31 slop* to es«t
Total elevation change 60 ft.
Slight
Perched: 6-12 ft.
Deepi 70 - 300 ft.
2(1 Municipal, 1 other uses)
Agriculture
A-J
None on sltet
20-30 within 1/2 mile
200 ft.
$30.247,900
No sand or gravel resources,
No sctive or potentially
active faults
Prohahly not of concern
South of Boulder -
Weld Coal Field
Low para., 0.06- 20 in/hr
Ned. to low shear strength
Hod. to high ahrlnk-awell pot.
Tea - if irrigated
0-31 slope toward southeast
Total elevation change 50 ft.
Moderate
Perched: 8-15 ft.
Dtep: 25 - 120 ft.
2(1 doneatlc, 1 irrigation
and stock)
Agriculture
A-3
-Non* on eite;
40 - 80 within 1/2 milt
900 ft.
$30,326,600
No sand or gravel reaourcea,
No active or potentially
active faults
Probably not of concern)
South of Boulder -
Weld Coal Field
Low pen., 0.06 - 20 In/hr
Med. to low sheer strength
Hod. to severe shrlnk-swell
pot.
Tea - If irrigated
3-91 dope around two knoll*
rear center of site;
total elevation change 35 ft.
Moderate
Perched: 8-12 ft.
Deep: 2) -70 ft.
0
Agriculture
A-3
None on tits;
30 - »0 within 1/2 sille
300 ft.
$30,110,400
No sand, gravel or recoverable
or gas.
No active or potentially
active faults
Probably not of concern:
South of Boulder -
Weld Coal Field
Low prra., 0.06 - 20 in/hr
Low ahear utrength,
Mod. ahrlnk-awell pot.
Yea - if irrigated
3-51 slope around knoll in
•outheaat corner; 0-31 (lope
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 "tie
50 ft.
$30,242,300
II Doea not Include coats of delaying project.
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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.
Summarized in Table 2 are the conclusions of the alternative site analysis.
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 projects
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. 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.
Participation in Existing Water Projects. Projects for which
Northglenn may be eligible for participation in with another municipality
include:
Aurora's Homestake Project
Colorado Big Thompson Project
Windy Gap Proj ect
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 Con-
servancy 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
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to existing users within the district. The extent of Northglehn'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.
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 fax exceed 5,000 cfs. 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. It now appears such
deep well rights will be granted.
Acquiring Existing Water Rights and Deep Wells. As explained in the EIS,
Northglenn decided to purchase some South Platte surface water (from
Consolidated Ditches among others) to secure sufficient make-up water
following initial denial by the State Engineer of their requested deep well
permits. Based on recent opinions of the Water Court, it now appears that
Northglenn will be permitted some if not all of the deep well water applied
for. If so, Northglenn could drill and produce this water, thereby having
excess supply for its design year needs.
The South Platte - Deep Well alternative includes combining the deep well
source and the South Platte surface source for raw water delivery. Under
these circumstances, an exchange with FRICO is no longer essential and a
wastewater system of transporting sewage to Denver Metro could be
implemented. The South Platte raw water would be treated at the Northglenn
water supply treatment facility now under construction. The South Platte
water would be diverted in accordance with the priority system and Northglenn
would return the historic depletion through Denver Metro supplemented as
necessary by release from storage.
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Participation in Existing Projects. The existing systems avail-
able for Northglenn to pursue as water supply options are: Denver Water
Board, Thornton, FRICO exchange, purchase or condemnation.. . . . .
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. 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 boudaries 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. 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 of Final EIS)
Costs of the alternative water supply/wastewater treatment systems
are shown in Table 3 and Table 4, and the estimated costs for Northglenn
to finance its portion of water supplied by Thornton is shown in Table 5.
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 im-
pacts. Northglenn's total water management program is expected to cost
$67 million with $6.9 million eligible under EPA regulations. As only
10 percent of the capital 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 a grant.
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TABLE 3 (8/15/80)
Surface Water
MUTER SUPPLY
Deep Wells & Surface Water Deep Wells
OPTION 1 OF
ITEM
Standley Lake Pipe
TreatjiHit Systan
Distribution, »tw&
Thornton Pipes
Deqj Wall d
Well #7
Maintenance Equip.
Const. Maintenance
6 Resident Engr.
Land & Eassnents
Contingencies, 25X
Eng. Legal &
Abninistrative, 15X
Overhead & AJnin.
Water Rights
Purchase
Subtotal
Replacement Water
Costs
TOTAL
CAPITAL COSTS
1,494,100
4,979,200
20,338,700
140,774
200,000
1,857,300
180,000
375,000
1,696,800
0
4.110,120
35,371,994
9,391,619
44,763,613
SALVAff
OSM VALUE
20,000 237,114
418,668 553,139
280,386 1,255,237
15,000 12,412
0 0
0 0
0 85,988
0 59,513
0 0
299,250 0
0 1.037.126
1,033,904 3,290,531
55,590 3,054,482
1,089,494 6,345,013
PRESENT WCRTH
Capital Cost Less
Thornton Pipes $27,650,313
Thornton Pipes
C&M
Salvage
Total P.W.
14,518,700
11,651,750
-6,345,013
$47,475,750
Annual P.W. ($/yr) 4,439,208
Unit Cost
(6840 AF/YR)
$1.99/1000 gal.
Annual Avg.
H>ushold Cost $261/>r
(131,400 gal/yr)
CAPITAL COSTS
1,494,100
4,979,200
20,338,700
629,984
200,000
1,857,300
180,000
375,000
1,696,800
0
4.110.120
35.861.004 1
6.512,560
42,373,564 1
TION 2
06M
20,000
418,663
280,986
116,171
0
0
0
0
0
299,250
0
,135,075
55.590
,190,665
OKflCm 3
SALVAZ
VALUE
237,114
553,139
1,255,237
55,543
0
0
85,988
59,513
0
0
1.037.126
3,333,660
2,009.431
5,343,091
PRESENT W3VTH
Capital Cost Less
Thornton Pipes
Thornton Pipes
C&M
Salvage
Total P.W.
$25,260,264
14,518,700
12,733,738
-5,343,091
$47,169,611
Annual P.W. ($/yr)
Uiit Cost
(6840 AF/YR)
Annual Avg.
Hxjsehold Cost
(131,400 gal/yr)
4,410,583
$1.98/1000 gal.
$260/y
CAPITAL COSTS
1,494,100
08M
20,000
4,979,200 418,668
20,338,700
2,240,860
200,000
1,857,300
180,000
375,000
1,696,800
0
4.110,120
37,472,080 1,
0
280,996
127,426
0
0
0
0
0
299,250
0
146,330
0
37,472,080 1,146,330
SALVAGE
VALUE
237,114
553,139
1,255,237
197,569
0
0
85,983
59,513
0
0
1.087,126
3,475,686
0
3,475,686
PRESENT MRTH
Capital Cost Less
Thornton Pipes
Thornton Pipes
O&M
Salvage
Total P.W.
Annual P.W. ($/yr)
Ihit Cost
(6840 AF/YR)
Annual Avg.
Household Cost
(131.400 gal/yr)
$20,358,780
14,518,700
12,259,591
-3,475,686
$43,661,385
4,082,547
$1.83/1000 gal.
$240/yr.
Cost updated fron Itrthglem Water Management Progran Vol. 2 4/20/77 IZS/jr.
Assurptions: Capital costs for the Standley Lake transnission main will not
change. Operational procedures dictate that a certain sis pipe
will be required to acconodate the diurnal flow variation Mien
coupled with reservoir facilities; therefore, it is assured that
the transmission main has been designed on these operating
constraints.
water right ptrchase is for the p-esently-owied
water in Standley Lake:
Total Water Rights Costs
Total Water Rights =
9.261.000 = S2940/AF
~1EO
9,261,000
10
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TABLE 3 (Continued)
HVTER SUPPLY
ITEM
Standley Late Pipe
Treatment Systan
FRICO EXCHANGE
CAPITAL COSTS
1,494,100
4,979,200
AGREEftNT OPTION !••
SALVAGE
(KM VALUE
20,000 237,114
418,668 553,139
Distribution, few&
Thornton Pipes
Deep Mell b
Well #7
feintenance Equip.
Cbnst. teirrtenance
& Resident Engr.
Land & Easanents
Contingencies, 25X
Eng. Legal &
20,333,70!)
140,774
200,000
.1,857,300
180,000
375,000
Administrative, 15* 1,696,800
Overhead & Adnin.
Water Rights
Purchase
Subtotal
Replacement Water
Costs
TOTAL
0
12.930.120
44,191,994
280,936 1,255,237
15,000 12,412
0 0
0 0
0 85,968
0 59,513
0 0
299.250 0
0 3,420,017
1,033,904 3,290,531
SOUTH PLAI it-uttp M-LL «.iuwi ivt
ITEM
Standley Lake Pipe
Treatment Systan
Distribution, few&
Thornton Pipes
Deep Wells
Raw Water Storage
at Treatment Plant
SB. Platte Alluvial
Wells, Puips & Trans
Maintenance Equip.
Const. Maintenance &
Resident Engineering
Land & Easanents
Contingencies
Eng. Legal & Adnin.
Overhead & Adnin.
CAPITAL COSTS
1,494.100
6,979.200
20.338,700
2,922,860
1,800,000
2,389,000
200,000
1,857,300
180,000
1,740,000
2,515,800
0
Mater Rights Purchase 4,110,120
9,391,619
53,583,613
55,590 3,054,432
1,089,494 6,345,013
Replacement Water
TOTAL
RESENT VCRTH
Capital Cost Less
Thornton Pipes
Thornton Pipes
04M
Salvage
Total P.W.
Annual P.W. ($/yr)
Unit Cost
(6840 AF/YR)
Annual Avg.
toushold Cost
(131,400 gal/y)
$36,470,313
14,518,700
11,651,750
-6.345.013
$56,295,750
5,263,920
$2.36/1000 gal.
$310/y
0_
46.527,080
SALVAGE
am VALUE
20,000 237,114
1,319,073 775,319
280,986 1,255,237
113,980 257,699
15,000 285,660
202,315 424,630
0 0
0 0
0 85,988
0 276,138
0 0
299,250 0
0 1,087,126
0 0
2,250,604 4,408,803
36*. 20 yr
64X, 50 yr
30>rs.
18t, 20 yr
82X, 50 yr
WESENT WCRTH
Capital Cost Less
Thornton Pipes
Thornton Pipes
OLM
Salvage
Total P.W.
Annual P.W. ($/yr)
Ihit Cost
(6840 AF/YR)
Annual Avg.
Household Cost
(131,400 gal/*-)
$29,413,780
4,408,303
24,069,409
-4,408,903
$63,593,086
5,946,256
$2.67/1000 gal.
$351/yr
Cost updated fron Nrthglem Water Rraganent Program Vbl. 2 4/20/77 13/>r.
Assumptions: Capital costs for tte Standley Lake transnission main will rot
change. Operational procedires dictate that a certain sis pipe
will be required to acconodate the diurnal flow variation vten
coupled with reservoir facilities; therefore, it is assured that
the transnission main has been designed on these operating
constraints.
*Assunes 3,000 AF/YR additional water for flow augmentation
required die to adverse water court ruling.
Water right purchase is for the p-esently-owied
water in Standley Late:
Total W&ter Rights Costs
Total Water Rights =
9.261.000 = $2940/AF
~
$9,261,000
11
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TABLE 4 (8/15/80)
COSTS CF ALTERATIVE NORTHGLENN WATER SUPPLY/W4STEW/\TER TREATMENT SYSTEMS
FRICO WVTER SUPPLY
WINDY GAP W\TER SUPPLY
Capital ($)
Water Supply
Wastewater
Total
Operations & Maintenance ($/yr)
Water Supply
Wastewater
Total
Present Worth ($)
Water Supply
Wastewater
Total
Annual Average hbusehold
Costs ($/yr)
Water Supply
Wastewater
Total
FRICO Agricultural Reuse Denver tetro
(Proposed Project Options) Wastewater Treatment
Option 1
44,764,000
24,213,000
68,977,000
1,089,000
530,000
1,619,000
47,476,000
26,680,000
74,156,000
261
155
416
Opt ion 1*
53,584,000
24,213,000
77,797,000
1,089,000
530,000
1,619,000
56,296,000
26,680,000
82,976,000
310
155
465
Option 3
37,472,000
24,213,000
61,685,000
1,146,000
530,000
1,676,000
43,661,000
26,680,000
70,341,000
240
155
395
56,191,000
15,037,000
71,228,000
1,066,000
661,000
1,727,000
55,336,000
19,690,000
75,026,000
305
114
419
NDrthglerm
Wastewater Treatement
Denver fetro
Wastewater Treatement
61,136,000
24.213.000
85,349,000
1,392,000
530,000
1,922,000
66,966,000
26.680,000
93,646,000
369
155
524
61,136,000
15.037,000
76,173,000
1,392,000
661.000
2,063,000
66,966,000
19,690.000
86,656,000
369
114
483
*Assunes 3,000 AF/YR additional water for flow augmentation due to adverse water court ruling.
-------
CO
TABLE 4 (8/15/80) (Continued)
COSTS CF ALTERNATIVE NQRTHGLENN WATER SUPPLY/WASTEWATER TREATMENT SYSTEMS
DENVER WVTER BOARD WVTER SUPPLY
SOUTH PLATTE CEEP WELLS
WVTER SUPPLY
Raw Water Contract
Capital ($)
Water Supply
Waste water
Total
Operations & Maintenance ($/yr)
Water Supply
Waste water
Total
Present Worth ($)
Water Supply
Wastewater
Total
Annual Average hbusetold
Costs ($/yr)
Water Supply
Wastewater
Total
Itrthglem
Wastewater Treatment
51,834,000
24,213,000
76,047,000
2,112,000
530,000
2,642,000
65,333,000
26,680,000
92,013,000
360
155
515
Denver Mstro
Wastewater Treatement
51,834,000
15,037,000
66,871,000
2,112,000
661,000
2,773,000
65,333,000
19,690,000
85,023,000
360
114
474
Full
Service Contract
fbrthglem Denver tetro
Wastewater Treatment Wastewater Treatement
54,843,000
24,213,000
79,056,000
2,626,000
530,000
3,156,000
71,215,000
26,680,000
97,895,000
392
155
547
54,843,000
15,037,000
69,880,000
2,626,000
661,000
3,287,000
71,215,000
19,690,000
90,905,000
392
114
506
Denver Metro
Wastewater Treatement
46,527,000
15,037,000
61,564,000
2,251,000
661,000
2,912,000
63,593,000
19,690,000
83,283,000
j : '
351
114
465
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TABLE 5
COST SUMMARY
THORNTON WATER SUPPLY CONDITIONS
Condition 1 Condition 2 Condition 3 Condition 4
Total Capital Cost ($) 25,300,000 45,600,000 93,900,000 114,200,000
Operation &
Maintenance ($) 2,940,000 2,940,000 2,940,000 2,940,000
$280,000 x 10.492
(Present Worth Factor)3
Total Present Worth ($) 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.
14
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DISCUSSION OF THE ENVIRONMENTALLY PREFERRED ALTERNATIVE
The previous section describes the alternatives to the Northglenn Water
Management Program that have been considered and evaluated by EPA. According
to recent regulations promulgated by the Council on Environmental Quality, the
sponsoring federal agency shall specify in the Record of Decision the
alternative or alternatives which are considered to be environmentally
preferable. Selection of such alternatives is determined by their impact upon
the natural and human environment rather than economic consideration,
technical factors or the agency's statutory missions. Of the various
combinations of water supply alternatives and wastewater alternatives
available to Northglenn, EPA believes that three of these alternative systems
are environmentally preferrable over other systems. These include: 1) water
supply from Thornton with Denver Metro wastewater treatment, 2) South Platte -
Deep Well water supply with Denver Metro wastewater treatment and 3) the
proposed FRICO exchange using deep wells for a make up water supply source
with agricultural reuse and a treatment plant located at any of the four sites
identified in the final EIS. These three alternatives have been selected
based upon the following significant environmental factors: agriculturial
productivity, water quality in the effected streams, potential health risks,
and site impacts.
Agricultural Productivity
The most severe environmental impact of transmountain West Slope
diversions from 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. Any new appropriation from
transmountain diversions of Colorado River water will compound these impacts.
If Northglenn were to acquire existing water rights currently diverted on the
west slope, the associated impacts could potentially be less in terms of both
water quality and agricultural impacts. West slope sources include the Denver
Water Board, the Colorado Big Thompson Project and the Windy Gap Project.
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 appropriation of surface water would have the
least effect on agricultural production. However, new surface water is not
available in the overly appropriated South Platte system.
The least impact to agricultural productivity of any alternative
considered is the FRICO exchange especially when the make up source is
obtained from deep wells (Option 3). This is due to the following factors:
1) Option 3 does not require the use of South Platte surface water, 2) all
exchange options provide additional water to the FRICO system because of the
10 per cent bonus, 3) condemnation or purchase of the FRICO source would
reduce agricultural production in the FRICO system significantly while
additional return flow to the South Platte through the Metro treatment plant
is unlikely to increase agricultural production along the South Platte where
15
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irrigation water is available in adequate amounts- to agricultural
appropriators. Option 3 is preferred over the Thornton water supply system
since Thornton's water purchases would dry up hay meadows in South Park and
like the South Platte - Deep Well alternative, expose the FRICO water to
further condemnation action.
Water Quality and Public Health Risks
Water quality changes in the Bull Canal downstream of the proposed
reservoir may preclude its potential use for domestic supply and may increase
public health risk due to public exposure to treated effluent and uncontrolled
reuse of effluent on raw edible crops. Such potential adverse impacts are
avoided by selecting an alternative which includes the Denver Metro wastewater
treatment alternative. While discharging effluent to the Bull Canal may
represent a loss of a possible domestic water sources (it would be possible to
deliver Standley Lake water by pipeline) it is the same action which further
enhances the liklihood that this water will remain for the purpose of
irrigation of agricultural lands.
There is a difference among experts as to the likelihood of the effluent
from the facility meeting the suspended solids limit as specified in the
permit. EPA1a analysis of the feasibility of the proposed system indicates
there is substantial likelihood that the proposed process will not limit
carbon, thereby not limiting algal growth.
For environmental reasons EPA does not endorse the use of copper sulfate
to control algae since there is a chance that concentrations of copper could
be released which would be deleterious to crop production. Acceptable
operational controls to reduce algal growth are readily available and the
environmentally preferred controls include selective discharge (controlling
the depth and timing of discharge) and the use of introduced fish to consume
algae. This problem would be avoided by selecting the Denver Metro wastewater
treatment alternative.
Site Impacts
Three alternative sites, all 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 any one of the sites. The key issue regarding site
selection has concerned possible adverse odor and a possible reduction in
property values to nearby residences (within one-half mile). At least 20
houses are within a half-mile radius of each of the sites. Site B has 80
residences within one-half mile. Because of recent developments in the area,
it is likely that in the near future residential growth will occur in the
vicinity of all sites. Site C is slightly less desirable than the others
because one household would have to be relocated. Otherwise, the agricultural
use of all four sites makes them equally suitable for the proposed facility.
It would be preferable due to possible odor problems to select a site that has
very few residences around it; unfortunately, rapid growth of residential
housing within the study area has made this impossible. Site problems would
be avoided by selecting the Denver Metro wastewater treatment alternative.
16
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EPA DECISION
EPA has decided to approve the Northglenn proposal and offers a grant,
with conditions, for approximately $7,615,000. (The final EIS indicated the
estimated grant at $6,948,000 based on capital costs, to which has been added
the normal estimate for costs of architectural engineering fees, inspection
fees and contingencies. The final grant award will be dependent upon the
actual construction bids.)
EPA recommends that the City of Northglenn proceed with the construction
of the proposed wastewater treatment facility on Site 10 in Weld County. This
decision is based on the condition that all mitigation measures and grant
conditions contained herein or in the Final EIS (1980) be accepted and
undertaken by the City of Northglenn.
If the applicant fails to comply with the mitigation measures contained
in the Final EIS (1980) and the conditions set forth in this Record of
Decision, EPA may consider any of the following actions:
1. Terminating or annulling the grant
2. Disallowing project costs related to noncompliance
3. Withholding project payments
4. Suspending work
5. Finding the grantee to be nonresponsible or ineligible for future Federal
assistance or for approval for future contract awards under EPA grants
6. Seeking an injunction against the grantee
7. Recovery of funds expended
8. Instituting such other administrative or judicial action as may be
legally available and appropriate pursuant to EPA regulations
40 CFR 30.920-5
This decision and the conditions are based on the Final EIS record,
specifically an analysis of the following factors:
1) the project includes certain benefits to agriculture as compared to
other alternatives or the situation if water condemnation litigation had
proven successful;
2) the proposal is the most cost-effective water supply and wastewater
system (see Table 4);
3) 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;
4) 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;
5) the State of Colorado has included the project on its fundable
project list for Fiscal Year 1979.
17
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6) 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;
7) additional public health control measures beyond those originally
proposed in the Northglenn facilities plan are required and will be
implemented by Northglenn; however the proposal identified in the Draft EIS to
prevent the sale of raw edible crops will not be required at this time;
8) assuming the Bull Canal is currently suitable as a domestic raw water
source, if the proposal is implemented the Bull Canal downstream of the Bull
Canal Reservoir will no longer be suitable as a source of domestic raw water,
since treated 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;
9) selecting one of the environmentally preferred alternatives that
includes continued wastewater treatment at Denver Metro ignores the legally
binding commitments that have been entered into by Northglenn, FRICO,
Thornton, and Westminster. Previous water condemnation actions against FRICO
resulted in the agreement among these parties for the water exchange with
FRICO. The exchange agreement between Northglenn and FRICO is a function of
water supply development which then translates into the need for Northglenn to
obtain control of its wastewater in order to satisfy the water exchange
agreement. Legal arrangements have been made to execute the exchange
independent of federal action.
Further detailed explanation of the analysis of some of these factors
follows:
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. 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 the extent of
agricultural benefits of the proposal was unclear. EPA decided that further
study of the possible economic impact upon agriculture was necessary.
18
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The agricultural economic analysis indicates 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. An
estimated value, of $1,950,000 in a similar year which productivity could be
lost if FRICO water was successfully condemned or purchased outright by
Northglenn or another municipality. The proposed Northglenn exchange plan is
therefore 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 or reduce the costs of maintaining current production levels.
EPA concludes 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.
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 are attributable to increased
nitrates in water from the canal include:
reduction in sugar beet purity
reduction in barley starch content
Based on comments from knowledgeable affected parties including Great
Western Sugar Company and Coors, Inc., EPA concludes that with 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 or value adversely.
Direct Effects of the Proposal
EPA1 s conclusions as to the nature, extent, and significance of direct
adverse impacts are:
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. (A proposed draft of an Intergovernmental Agreement
offered by Northglenn includes payments in lieu of taxes.) ,
Effect on Adjacent Land Values - A decrease in adjacent residential
values up to five percent is possible. No change in farmland values
is anticipated. No mitigation for such possible reduction in
residential property values is recommended.
Groundwater pollution - The proposed clay liner of the reservoir and
lagoon system will minimize any change in groundwater quality.
Additional construction measures will be required by EPA and the
Corps of Engineers to properly seal well penetrations and/or an
inactive fault, if present. No adverse impact upon groundwater is
predicted.
19
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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. The probability is judged to be slight, and mitigating
measures are incorporated into the plan.
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.
The Proposal Qualifies for EPA Funding
EPA has proposed alternative methods 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 has
determined that Northglenn's proposed project is eligible for grant awards as
a multi-purpose project using alternative technology. Using the 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 the eligible fraction of the multiple-purpose project costs are
determined. 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.
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.)
20
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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 Flan. 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 in agricultural use to reuse all water generated by
the treatment plant throughout the design life of the plant.
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 over appropriated South Platte system must comply
with Colorado 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.
-------
These legal-issues will be resolved through the judicial process. EPA
concludes that some changes to the water plans as filed may thereby be imposed
but the probable effect of any such changes during the court process will
likely be limited to requirements for additional water for augmenting
purposes. Northglenn can acquire such additional water from non-agricultural,
agricultural or a mix of sources similar to their present plan.
Need for Additional Public Health Control Measures
Based upon review of the medical literature, and EPA and Colorado
policies, EPA concludes that to provide the highest possible degree of
protection of public health, the following additional measures not initially
proposed by the applicant nor normally incorporated into NPDES permits are
necessary:
1. Chlorination of Bull Canal effluent prior to discharge, to assure
limitation of the concentration of fecal coliform bacteria to not
more than 200 fecal coliform organisms per 100 milliliters (ml).
A permit criterion of 1000/100 ml has been considered
sufficient for agricultural use where some dilution of the
effluent would occur. Northglenn has agreed to meet a permit
criterion of 200/100 ml for the discharge into Bull Canal. For
comparison, the fecal coliform limit in the NPDES permit for
the Denver Metro facility is 1000/100 ml. This effluent is at
times discharged into the Burlington Ditch.
2. Control of irrigation runoff into the Towns of Frederick and
Firestone.
Present agricultural practices combined with a lack of proper
stormwater drainage allows runoff to flow along certain streets
of these communities. Northglenn will be required to intercept
and control these flows in order to further reduce public
contact with tailwater runoff which may consist in whole or in
part of treated sewage effluent.
3. Disinfection of Bull Canal water supplied to Dacaono's nonpotable
irrigation system.
The Town of Dacono operates a nonpotable water system used for
lawn and garden irrigation. Its source is Bull Canal water
which may consist in whole or in part of treated wastewater
effluent from the Northglenn facility. In order to minimize
the potential for disease transmission in this situation,
Northglenn is required to disinfect this source of nonpotable
water, or replace its source.
22
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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 irrigated with effluent
from the Northglenn facility. The draft EIS contained the following proposed
grant condition:
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 conditions which provide sufficient detention time. Pathogen
survival will be further reduced by chlorination of the effluent to meet the
limit of fecal coliform bacteria concentration of not more than 200/100 ml.
EPA concludes that public health risks under these conditions are not
significant and that the public health will be adequately protected. However
there is still some unknown albeit small risk that waterborne disease could be
transmitted to humans who ingest raw vegetables irrigated with water from the
Bull Canal.
At this time, EPA has not developed criteria or guidelines to establish
treatment criteria for the use of sewage effluent on raw edible crops. During
the next two years the Agency intends to establish national guidelines for
effluent criteria for unrestricted agricultural reuse. Upon completion of
Agency action in this regard and upon permit renewal, Northglenn will be
required to comply with these new guidelines.
If the Northglenn facilty is capable of meeting such new requirements or
if it is determined that operational or design changes are necessary and
cost-effective to meet these requirements, then compliance will be obtained.
In the event that compliance with future Agency guidelines as applied to is
not cost-effective for the Northglenn facility, appropriate measures to
protect public health will be required.
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 treated
wastewater, EPA recommends farmers locate process markets for the crops.
23
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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 may receive some flow from Bull Canal as their future
domestic water supply source. 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.
The use of treated 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 the Town of Frederick should seek an alternative water supply
sour ce.
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STEPS TO MINIMIZE ADVERSE EFFECTS
Summary of NPDES Permit Conditions
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 an municipality, industry, or other entity
discharging into waters of the United States may do so only 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.
Northglenn has concurred that certain impacts will require mitigation,
particularly those associated with changes in quality of the water of Bull
Canal. EPA has developed the following mitigating programs for the impacts
identified:
1) Potential for disease transmission through direct body contact with
Bull Canal water, as a result of farm irrigation practices and public
recreation around the Bull Canal.
The NPDES permit effluent limitation is: "The City shall chlorinate
the effluent prior to discharge to achieve a criterion 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."
2) 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 change in quality of the water in the Bull
Canal will unnecessarily cause an increased health risk within Dacono.
Northglenn will resolve this problem by either substituting an alternative
water source for Dacono's use in place of the Bull Canal water currently used,
or installing and operating a system to disinfect 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 a chlorine level of not less than 0.3 mg/1.
EPA is negotiating to include the following as a NPDES permit condition
and will also require it as a grant condition: "Northglenn will undertake the
cost of installations, operation and maintenance of a disinfection system 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 suitable 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.
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3) During irrigation periods, Bull Canal tailwater from lands nadj acent-
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 as 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 it as a grant condition: "Northglenn will provide
physical measures to prevent the flow of tailwater from the Bull Canal from
adjacent agricultural land into any residential area. Consultation with
Frederick and Firestone on the design and location of these facilities is
necessary."
Alternatively, at Northglenn's expense, a suitable replacement for this
system could be provided, in which case this permit condition would be
withdrawn. Northglenn shall consult with the Towns of Frederick and Firestone
and the property owners to obtain their concurrence with these plans.
4) Protection of Treatment Capacity
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
accommodate flows for this population. A substantially higher rate of
development in Northglenn or expansion of the service area would create the
need to expand the facility before the year 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.
Northglenn1s ordinances as described in the 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."
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Summary of. EPA Grant Conditions
Under EPA's Construction Grants Program, a grant offer contains a list of
requirements to which 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. The following grant conditions must be met by
Northglenn to receive final grant payment:
1) Regarding the possible irrigation of private gardens, Northglenn has
agreed to develop an educational plan that will inform farmers of the problem
and discourage direct contact with the water and its use on private gardens.
The EPA grant condition is: "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 Standley 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."
2) 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. 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 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.
The EPA grant condition is: "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."
3) 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 20 year design life of the project. 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 in
agricultural use and under the City's control will be continuously committed
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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.
The EPA grant condition is: "Northglenn shall assure that sufficient
land in agricultural use, 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. Further, Northglenn will assure that
discharge only occurs when there is irrigation use. This condition is binding
for the 20-year design life of the project."
4) 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.
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.
EPA has required as a 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 six
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."
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5) 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 contam-
ination of water and subsequently crops by heavy metals, and pathogenic
organisms.
EPA has required the following grant condition: "A monitoring
program will be developed to include locations and depths of ground-
water 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.
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 con-
dition 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 noncon-
formance 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.
6) 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
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County has 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.
EPA has required the following grant condition: "The City of
Northglenn and Weld County shall share responsibilities as Management 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."
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.
Urban Runoff Controls
Erosion Controls
Water Conservation Efforts
Radiological Emergency Response Plan
Archaeological/Cultural Resources
Analysis of Recreational Potential
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With certain limited exceptions, EPA has accepted Northglenn1s-efforts to
fulfill these conditions. The current status of these efforts includes the
following:
1) 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.
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 a willingness to
comply 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.
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. EPA finds that the Northglenn Plan is in conformance with the Colorado
State Implementation Plan (SIP) in accordance with Section 176(c) of the Clean
Air Act. Accordingly, EPA has required 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 (SIP). Specific measures required under the SIP for
local governments including Northglenn include consideration of a local
smoking vehicle control ordinance, bicycle and pedestrian facility
requirements for local zoning ordinances, and subdivision regulations.
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 serve 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(fa) of the Clean Air Act of
1977 have been met."
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2) Urban Runoff Controls . . •
The Denver Regional Council of Governments recommended in Che 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 the 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 the 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".
EPA accepts this ordinance as written as suitable to meet the
requirements of an urban runoff control plan. Accordingly, EPA has required
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."
3) 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 not yet implemented this provision. Accordingly, EPA will require the
following grant condition: "Northglenn will adopt measures to limit erosion
and to control sediment prior to final payment of the grant. Northglenn will
prepare and adopt an ordinance specifying erosion controls that follows: Guide
for Erosion and Sediment Control in Urbanizing Areas of Colorado; Interim
Guidance, 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 requirement to
implement the erosion and sediment control requirements for new development as
included in the DRCOG 208 Clean Water Plan."
4) 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).
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.
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In addition, Northglenn is also in the process of adopting a city
ordinance to specifically promote water conservation. This recommended
ordinance is entitled "Water Conservation and Plumbing Code of 1979."
EPA has imposed 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
be adopted and remain in effect for the design life of the project."
5) 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 1 area (5 mile radius). Accordingly, EPA has determined
Northglenn must comply with provisions of the Radiological Emergency Response
Plan for Rocky Flats.
EPA has applied 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."
6) Archaeological/Historical Resources
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 has applied
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."
7) Analysis of Recreational Potential
During the review of the final EIS, EPA was notified that the present
planning efforts failed to formally consider potential recreational
opportunities of the proposal. While many informal discussions were held
regarding recreation at the proposed plant site such as waterfowl observation,
trails, etc., a complete review of options for recreation has not yet been
accomplished.
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Accordingly EPA has required the following grant condition: "Northglenn
will submit an analysis of recreational potential of the proposed exchange
plan. This analysis shall he accomplished by close coordination with Adams
County, the Denver Regional Council of Governments, the Heritage Conservation
and Recreation Service and the State of Colorado. Said analysis shall provide
opportunity for public involvement and shall be due to EPA prior to 50 percent
construction completion."
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RESPONSE TO COMMENTS RECEIVED ON THE FINAL EIS
Eleven written comments were received and twelve individuals presented
oral statements at the public hearings following the publication of the
final EIS on June 27, 1980. Three of the oral statements were duplicated by
written comments. Six of the respondents, of which four were consultants to
the City of Northglenn, favored the project, with eleven in opposition to
all or a portion of the project. Two other respondents asked questions of
timing or specific effects. EPA has reviewed all of these comments and
offers the following response to the major issues raised.
Agricultural Productivity
The Consolidated Ditches Company engaged W.W. Wheeler and Associates
and Charles E. Turner, P.E., presently associated with Colorado State
University, to review the impact of the project and alternatives upon
agricultural productivity. In Mr. Turner's 25-page report entitled
"Analysis of Agricultural Productivity as Used in the Final Northglenn EIS",
June 1980, he criticizes the methodology and economic theory of the analysis
in the EIS. The basic complaint is that by using 1979 year water use data
for FRICO and average year data for the South Platte System, the analysis is
inaccurate, since 1979 was wetter than normal. Mr. Turner then provides an
alternative method (the Blaney-Criddle Procedure) for determining economic
value per unit of water. Use of this method alters the conclusion that the
Northglenn proposal provides some benefits to the agricultural community.
Turner's analysis indicates that an alternative which relies on continued
wastewater treatment at Metro and a return flow to the South Platte is
preferable.
Only limited crop yield data was available for FRICO, primarily 1979
data. The EIS analysis used 1979 crop values for both systems. Average
year water use data for the South Platte system was also used. Since the
FRICO system is water short the estimated average economic productivity for
FRICO is not unduly affected by higher precipitation. The water use pattern
of FRICO is to use all available supplies to irrigate more land or crops
needing additional water. In 1979, FRICO water use was 40 percent higher
than in the average year despite the additional rainfall, because the wetter
year provided a larger Standley Lake reserve. In the adequately, even
overly irrigated, South Platte system, however, where land not water is the
factor limiting agricultural productivity, water use from direct flow
ditches is less during wetter years. The average year water use is the
appropriate data reference for the South Platte system. Therefore, the use
of such a data base results in a conservative approach for estimating
production value per unit of water.
The Blaney-Criddle procedure is used as a water supply planning tool.
The Blaney-Criddle procedure assumes that the crop evapotranspiration rate
varies directly with the sum of the products of mean monthly air temperature
and monthly percentage of daytime hours. The consumptive use rate of crops
determined by this procedure is valid to determine what water supply is
necessary for optimal production of a crop. The irrigation requirements of
a crop are made up by the consumptive use requirement of the crop as
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determined by the Blaney-Criddle procedure after accounting for effective
precipitation plus water withdrawn from storage in the soil during the
growing season. (See "Irrigation Water Requirements" USDA, SCS, Engineering
Division, Technical Release No. 21, September 1970). In a report by Blaney
and Griddle it is stated: "Accordingly, the Blaney-Criddle methods assumes
that with adequate water available, consumptive use varies directly with
monthly mean temperature multiplied by monthly percentage of daytime hours
of the year, and with the type of crop grown." (emphasis added) (From
Blaney, H.F. and Griddle, W.P, "Report on Irrigation Requirements for West
Pakistan", produced for Tipton & Kalmbach, Inc., Denver, April 30, 1957,
page 3.)
Hence reliance on Blaney-Criddle as a method of comparing the
agricultural productivity of two parcels of land is misplaced unless there
is a comparable supply of water for each.
The FRICO irrigation system does not have a full water supply
available for crop production and the "potential" evapotranspiration rate
determined by the Blaney-Criddle procedure can not be achieved under field
conditions since the full moisture supply is not available.
In the South Platte system most of the canals have very senior water
rights and are able to provide the optimal requirement for their crops.
Under this circumstance the evapotranspiration rates estimated by the
Blaney-Criddle procedure are valid and can be achieved under field
conditions. EPA believes the 0.67 acre-foot per acre of consumptive use of
irrigation water for FRICO as presented in the EIS is realistic, primarily
because FRICO does not have a full water supply available to the crops.
While the 1.66 acre-foot per acre of consumptive use of irrigation water
developed by Turner may be optimal, it is inaccurate since it is based on
the assumption that crop water requirements are completely satisfied.
EPA believes the analysis of agricultural productivity as contained in
the EIS is reasonable and warrants the conclusion that net agricultural
production is greater for the exchange options than for condemnation or
purchase of FRICO water supplies with a discharge to the South Platte
through Denver Metro. The use of the South Platte - Deep Wells alternative
gives an intermediate result (less than Option 3 but greater than Option 2)
and also exposes the FRICO water to conversion from agricultural to other
uses (see Table 6). Therefore assisting Northglenn in this project is
consistent with EPA policy to protect environmentally significant
agricultural lands.
Impacts Due to Canal Lining and.the Flow Augmetation Plan
Several commentors stated that the EIS failed to fully analyze the
agricultural and environmental impact due to canal lining. FRICO intends to
line most of the Bull Canal system in order to improve efficiency of water
delivery. The final EIS summarized studies undertaken by consultants for
FRICO and Northglenn which evaluated canal losses due to seepage. The
report by Wright-Water Engineers concluded that seepage loss along Big Dry
Creek was too small (five percent) to warrant lining and that due to
urbanization such losses may eventually be reversed. Total losses along
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TABLE 6
CO
GROSS PRODUCTIVITY OF FRICO AND SOUTH PLATTE
IRRIGATED LANDS AFFECTED BY THE NORTHGLENN PROJECT
(IN MILLION DOLLARS)
FRICO1
SOUTH PLATTED
TOTAL GROSS
PRODUCTIVITY
Option Description
i Without deep wells
2 650 acre-feet from non-
tributary wells
.1
3 2300 acre-feet from non-
tributary wells
It Water from Standley Lake
Wastewater to Metro
i
South Platte - Deep
Well Alternative
Average Year
1.95
1.95
. 1.95
1.49
^1.90
Dry Year
1.76
1.75
1.74
1.04
1.61
Average Year Dry Year Average Year Dry Year
0.16
0.33
0.53
0.53
0.53
0.15
0.31
0.48
0.48
0.48
2.11
2.28
2.48
2.02
2.43
1.91
2.06
2.22
1.52
2.09
Based on $342/acre-foot of consumptive use of irrigation water. FRICO deliveries given in Table 4 of Final EIS,
irrigation efficiency = 65% in average year and 70% in dry year.
^ 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 $60/acre.
Sample Calculation - Option 1, Average Year:
FRICO
Farm Headgate Delivery = 6390 A-F
Productivity oE Irrigated Land •= (6390)(.65)(342)=$!.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)=$0.096^
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.
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Bull Canal were estimated by Hydro-Triad to be 40 percent of the Standley
Lake releases (see page 76 of final EIS). Subtracting the estimated five
percent seepage loss along Big Dry means that during an average year changes
in flow affected by canal lining could amount to 3500 acre-feet per year
(35 percent of average annual release of 10,000 acre-feet). This water is
currently lost due to canal bank evapotranspiration and evaporation as well
as groundwater recharge.
Several commentors indicated that substantially all this water has
historically recharged groundwater which then flows to the South Platte
River. If so, stream flow could be reduced by that amount. Relatively
small changes in stream flow would not economically impact the direct flow
irrigators, since there is sufficient river flow to physically divert and
they are sufficiently senior so as to assure priority.
If the water court determined that any quantified water losses due to
canal lining must be offset by a flow augmentation plan there could be both
an adverse economic impact to agriculture and to the responsible party. If
one assumes that 3000 acre-feet must be augmented annually and that the
source is other agricultural water, then agricultural production could
drop. (Note: In the EIS the agricultural productivity analysis eliminated
both the adverse effects of obtaining this water and any benefit in the
FRICO system that canal lining provides). It is not clear in the event of
such a water court ruling whether FRICO, Northglenn, or another party would
be responsible to replace such water. If Northglenn were responsible, then
it is possible that capital costs of the system could increase by the cost
of such water augmentation. At the present price of water ($3000 per
acre-foot in the area) 3000 acre-feet would cost $9 million. The cost of
the Northglenn proposal under these circumstances in shown in Tables 3 and
4. It remains EPA1s position as presented in the EIS that lining of the
Bull Canal by FRICO is a private action unrelated to EPA's or any federal
action and the issue will have to be resolved in water court.
Several objectors to Northglenn's flow augmentation plan have opposed
the plan on the basis that the exchange will increase historical depletions,
i.e. decrease stream flow previously available to other water users.
Northglenn's plan includes a claim for 100% depletion credit for its storage
rights. These sources may have had some historical return flow to the South
Platte system. In view of EPA policies to protect agricultural land, EPA
considered and rejected the following grant conditions:
"Northglenn shall revise its flow augmentation plan so that there will
not be an increase in historical stream depletions except if such depletion
is due to canal lining".
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Such an admittedly ambiguous condition would be meant to force
Northglenn to revise its augmentation plan to met the environmental and
social objectives of further protecting farmlands and maintaining historical
stream flow. If implemented the condition would be intended to prevent
Northglenn from obtaining 100% depletion credit on its purchase of Standley
Lake (FRICO shares) storage water and its claims to 300 acre-feet per year
of sewer line infiltration. Stream depletion due to canal lining would be
exempt since it is generally recognized that a farmer's ability to line
canals without augmentation is desirable in order to provide an incentive to
improve irrigation efficiency. Of course the legal contraints on water
transfers in Colorado are based upon a century of property rights experience
and not based upon such factors that may be considered to be in the best
interests of the public. Transfers of water are usually approved through
private bargaining for such property rights amoung those affected parties.
Public scrutiny of the effect is provided by the State Engineer's office and
subject to water court procedures. Some prior appropriation states have
recently revised their water law to avoid some of these abuses and
ambiguities and have therefore limited water transfers to those deemed to be
in the public interest.
EPA decided not to apply this grant condition because it would
interfere with Northglenn's rights under Colorado water law. Anyway the
agricultural productivity of the proposed plan has been determined to be
beneficial and therefore sufficient to be compatible with EPA policy to
protect agricultural land without such a grant condition. Nevertheless EPA
encourages Northglenn to resolve the objections to their flow augmentation
plan as expediously as possible.
EPA also received several requests to delay grant award until such
time as the Northglenn Flow Agumentation Plan has been approved by the water
court. Some of these objections were based on the concept that failure to
obtain water court approval of the plan as submitted could even mean federal
funds would be wasted on an unuseable system. Based upon expert opinion
provided to EPA, the more likely situation is that water court approval may
change but not negate the exchange plan. EPA believes it is generally
unnecessary to delay any grant until all pending litigation is resolved. At
this point all EPA grant requirements have been satisfied. The grant award
is limited to eligible portions of the proposed wastewater treatment and
reuse system. If for any reason Northglenn does not construct and operate
this system in accordance with the facilities plan EPA could terminate and
anull the grant seeking recovery of funds expended and other such
adminstrative or judicial actions as may be legally available persuant to
EPA regulation 40CFR30.920-5.
Tailwater Control
Several objectors to the plan indicated that the EPA requirements to
require tailwater control created additional problems. It was stated that
elected officials are not likely to approve or allow construction of the
tailwater control structures due to community opposition to the entire
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project and a belief that:stored wastewater creates a public nuisance such
as fostering mosquitoes. It is EPA's intention in placing this requirement
upon Northglenn to reduce the unnecessary public contact with treated
effluent which might result from tailwater runoff into residential areas.
If the community and land owners continue to oppose the use of the land in
this manner, Northglenn may need to use eminent domain to acquire this
property in order to-comply with the grant condition. Alternatively, if
future residential growth or the ongoing condemnation action against the
water right owner is completed, then the grant condition will be met by not
irrigating these areas. The tailwater ponds will not create new mosquito
breeding habitat since the water will be pumped automatically until all
water is consumed by the crop or infiltrates the soil.
Intergovernmental Agreement with Weld County
In response to EPA, the Commissioners of Weld County indicate they are
reluctant to enter any agreement to enforce grant conditions. Weld County
has misinterpreted EPA's requirement for Northglenn to negotiate an
Intergovernmental Agreement (IGA) with Weld County. Although EPA recommends
that the IGA contain many of the same measures contained as EPA grant
conditions, the purpose is not for Weld County to enforce EPA requirements.
Rather if Weld County concurs that such measures or other measures are
necessary and desirable for the citizens of Weld County, they can mutually
agree with Northglenn to monitor compliance and be reimbursed by Northglenn
for their expenses. EPA is prepared to enforce required grant conditions as
specified in the section on "EPA's Decision" in this Record of Decision.
Compensation for Reduction in Residential Property Value
EPA has received several requests that EPA should require Northglenn
to pay property owners the difference in appraised real estate value. The
facility has been designed and should be operated in accordance with
applicable state and federal regulations. There is the possibility as
analyzed in the Final EIS, that an odor nuisance could occur if the plant is
operated improperly. The course of action for these property owners may be
through the courts in order to quantify any losses.
Analysis of Recreational Potential
The Denver Regional Council of Governments suggested to EPA that a
formal review of recreational opportunities should have been included in the
EIS analysis. EPA concurs and notes that while Northglenn officials have
informally discussed such opportunities including water fowl habitat
enhancement, a trail around the proposed reservoir and many other
recreational facilities, none of the suggestions are planned. The DRCOG
1977 report entitled "Regional Parks, Recreation and Open Space Plan" shows
a planned bike path between Barr Lake and Boulder which parallels the last
mile of the proposed interceptor. EPA suggests that this opportunity as
well as options for other bike routes, for tours of the facility, public use
of the facility site, and other recreational facilities be evaluted by
Northglenn. EPA has therefore added a grant condition that requires
Northglenn to prepare an analysis of recreational potential prior to
50 percent grant payment. (See list of grant conditions in the preceding
section.)
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Compliance with Provisions of the Clean Air Act
The Denver Regional Council of Governments in comments to EPA
indicated that they concur with EPA's finding that the project is consistent
with the State Air Quality Implementation Plan (SIP). However, DRCOG
indicated that there are specific measures required under the SIP for local
governments to consider and that Northglenn has not yet considered these
issues. These measures include consideration of a local smoking vehicle
control ordinance and bicycle and pedestrian facilities for new residential
development. These requirements have been added to EPA's grant conditions
regarding compliance with the SIP.
Cost Analysis for the South Platte - Deep Well Alternative
The analysis in the final EIS of the South Platte - Deep Well
alternative did not include a detailed analysis of the cost of the
additional well fields, pipelines, storage and treatment facilities which
would be necessary to implement this alternative. A detailed estimated cost
of this alternative is shown in Table 3 along with the other alternatives
considered. In addition to the water supply facilities proposed under
Option 3 which include the water treatment plant, (the Standley Lake
pipeline is still necessary under this option in order to deliver
Northglenn-owned water) and the purchase of the existing water distribution
system from Thornton, the following items are also necessary:
Estimated
Item Capital Cost
1. South Platte well field, pumps, transmission $2,384,000
line to treatment plant.
2. Raw water storage reservoir near treatment 1,800,000
plant (1000 acre/feet).
3. Additions to treatment plant for water 2,000,000
softening.*
4. Additions to the Deep Well field. 542,000
5. Engineering contingencies 2,324,OOP
legal and administration at 40%.
Total $9,055,000
* Due to the high dissolved solids content of the shallow well water,
water softening equipment would be necessary. The average total
dissolved solids (TDS) of the alluvial shallow wells is 800 to 1000
mg/1 and TDS of the deep wells would be 100-200 mg/1. When blended,
the TDS would exceed the 500 mg/1 the recommended limit under the Safe
Drinking Water Standard. Therefore precipitation of solids and
hardness is necessary.
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As proposed by Consolidated Ditches, this alternative would also
require Northglenn to provide FRICO 500 acre/feet annually in order to meet
the minimum return flow called for in the FRICO-Northglenn Exchange
Agreement. If necessary, this item would be common to any alternative which
relied upon the Denver Metro wastewater treatment alternative. For
consistency, the cost of this item, estimated at $1,580,000 is not included
here since it was not included in the cost of the other Denver Metro
alternatives.
The capital cost of this water supply alternative when combined with
the less costly Denver Metro Wastewater treatment system is less than the
proposed exchange plan. When the higher operation and maintenance costs, are
included, this alternative is 12 percent higher based on present worth cost
than the proposed exchange plan under Option I. Therefore, the results and
analyses stated in the EIS regarding the cost selection of alternatives are
not changed.
An estimate of agricultural productivity of this option has also been
made (see Table 6). The results indicate that the estimated total
productivity of $2.43 million under the South Platte-Deep Well option during
an average year is slightly less than Option 3 and greater than other
options. Hence the conclusions reached in the EIS that Option 3 has the
highest agricultural productivity remains the same.
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.-
EPA-908/5-5-79-002D
2.
3. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
Record of Decision
Northglenn Water Management Program
City of Northglenn, Colorado
5. REPORT DATE
September 9. 1980
6. PERFORMING ORGANIZATION COOE
7. AUTHOR(S)
Weston W. Wilson, EPA
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
U.S. Environmental Protection Agency
Region VIII
1860 Lincoln Street
Denver, Colorado 80295
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 80295
13. TYPE OF REPORT AND PERIOD COVERED
Final
14. SPONSORING AGENCY CODE
15. SUPPLEMENTARY NOTES
Draft Environmental Impact Statement dated January 11, 1980 and Final Environmental
Impact Statement dated June 27, 1980 issued by EPA.
16. ABSTRACT
This is a public record of decision regarding 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 agreement with
the Farmers Reservoir and Irrigation Company, approximately 5,000 acre-feet of
water will be diverted annually 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, has authorized a grant for 75 and up to 85 percent matching funds for
construction costs of the proposed 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 were in progress.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS C. COSATI Field/Group
Wastewater Reclamation
Sewage Irrigation
Agricultural Reuse
Alternative Wastewater Treatment Techno!o
Environmental Impact Statement
Record of Decision
iy
Denver Regional EIS fo
Wastewater Facilitie
and the Clean Water
Denver Metro Sewage
Farmers Reservoir and
Irrigation Company
'rogram
18. DISTRIBUTION STATEMENT
Release Unlimited
19. SECURITY CLASS (This Report)
21. NO. OF PAGES
43
20. SECURITY CLASS (This page)
22. PRICE
EPA Form 2220-1 (Rev. 4-77) PREVIOUS EDITION is OBSOLETE
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