Douglas Wastewater Treatment Plant Upgrade and
Bay Acres Colonia Wastewater Collection System Expansion
For the City of Douglas, Arizona
Environmental Assessment
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January 7, 2014
U.S. Environmental Protection Agency, Region IX
75 Hawthorne Street
San Francisco, California 94105
Border Environment Cooperation Commission
Comision de Cooperation Ecologica Fronteriza
Blvd. Tomas Fernandez, No. 8069
Cd. Juarez, Chihuahua, Mexico
Telephone: (011-52-16) 25-91-60
Douglas, Arizona
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Environmental Assessment
Douglas Wastewater Treatment Plant Upgrade and Bay Acres Colonia Wastewater Collection System Expansion
TABLE OF CONTENTS
1.0 INTRODUCTION 1
1.1 STUDY LOCATION 1
1.2 PURPOSE AND NEED 3
1.3 SCOPE OF ANALYSIS 3
2.0 PROIECT DESCRIPTION AND ALTERNATIVES 4
2.1 PROPOSED ACTION 4
2.2 ALTERNATIVES CONSIDERED—DOUGLAS WASTEWATER TREATMENT PLANT 5
2.3 ALTERNATIVES CONSIDERED—BAY ACRES COLONIA 9
3.0 AFFECTED ENVIRONMENT 14
3.1 LAND USE 14
3.2 SOILS 14
3.3 WATER RESOURCES 15
3.4 VEGETATIVE HABITAT 16
3.5 WILDLIFE RESOURCES 17
3.6 CULTURAL, HISTORICAL, AND ARCHAEOLOGICAL RESOURCES 18
3.7 AIR QUALITY 18
3.8 NOISE 19
3.9 ENERGY AND NATURAL RESOURCES 19
3.10 ROADWAYS AND TRAFFIC 20
3.11 HAZARDOUS MATERIALS 20
3.12 SOCIOECONMICS 20
3.13 ENVIRONMENTAL IUSTICE AND PROTECTION OF CHILDREN 21
3.14 SUSTAIN ABILITY AND GREENING 22
3.15 HUMAN HEALTH AND SAFETY 22
4.0 ENVIRONMENTAL CONSEQUENCES 23
4.1 LAND USE 23
4.2 SOILS 23
4.3 WATER RESOURCES 24
4.4 VEGETATIVE HABITAT 25
4.5 WILDLIFE RESOURCES 26
4.6 CULTURAL RESOURCES 27
4.7 AIR QUALITY 27
4.8 NOISE 28
4.9 ENERGY AND NATURAL RESOURCES 29
4.10 ROADWAY AND TRAFFIC 29
4.11 HAZARDOUS MATERIALS 30
4.12 SOCIOECOMICS 30
4.13 ENVIRONMENTAL IUSTICE AND PROTECTION OF CHILDREN 31
4.14 SUSTAIN ABILITY AND GREENING 31
4.15 HUMAN HEALTH AND SAFETY 31
4.16 CUMULATIVE EFFECTS 32
APPENDIX A CLASS III CULTURAL RESOURCE SURVEY 34
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Environmental Assessment
Douglas Wastewater Treatment Plant Upgrade and Bay Acres Colonia Wastewater Collection System Expansion
1.0 INTRODUCTION
The United States Environmental Protection Agency (EPA) administers the Border Environment
Infrastructure Fund (BEIF), which provides grant funding for water and wastewater infrastructure
projects located along the international boundary between the United States (U.S.) and Mexico.
EPA policy for use of border funds requires evaluation and certification of projects by the Border
Environment Cooperation Commission (BECC) as a condition for grant award. As part of the
BECC certification process, the proposed project must comply with (1) Mexican environmental
regulations and (2) the National Environmental Policy Act (NEPA). The EPA requires compliance
with NEPA before BEIF funds can be authorized. Projects within 62 miles (mi) (100 kilometers
[km]) of the U.S./Mexico border are eligible for BEIF assistance.
In accordance with the U.S. Council of Environmental Quality (CEQ) regulations, 40 CFR Parts
1500-1508, and EPA regulations (40 CFR Part 6) as guidance, this EA documents the
environmental consequences in the US of the proposed federal action. The purpose of this
document is to comply with NEPA documentation requirements for the proposed federal action
under consideration, which consists of the City of Douglas Wastewater Treatment Plant Upgrade
and Bay Acres Colonia Wastewater Collection System Expansion.
1.1 STUDY LOCATION
The City of Douglas is located in the southeastern corner of Arizona in Cochise County (see Figure
1.1). Douglas is on the US-Mexico International Border adjacent to the City of Agua Prieta,
Mexico, approximately 119 miles southeast of Tucson, Arizona. Douglas is located at latitude
31°20'38.65"N, and longitude of 109°32'42.79"W. State Highway 80 (Pan American Avenue)
runs north-south through the community and is the main access to Douglas. The San Bernardino
and Leslie Canyon National Wildlife Preserves are located 16 miles from Douglas. The Chiricahua
Mountains are approximately 40 miles northwest of Bay Acres Colonia.
The community consists of residential housing, small commercial districts, a 2,000 inmate prison,
hospital, fire station, post office, police department, recreation center, and an aquatic center. The
Bay Acres Colonia is located in the northeastern part of Douglas, outside of the City limits and
south of Highway 80. The City of Douglas is currently serving the residents of Bay Acres with
drinking water service; all of the residences have decentralized onsite sewage treatment systems,
many of them inadequate and non-functioning.
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Douglas Wastewater Treatment Plant Upgrade and Bay Acres Colonia Wastewater Collection System Expansion
Figure 1.1: Project Location Map
1.2 PURPOSE AND NEED
The expansion of the wastewater collection system to the Bay Acres Colonia and upgrade of the
Douglas Wastewater Treatment Plant addressed in this EA are intended to provide improved
health, sanitation, and security to the residents of the Bay Acres Colonia and the City of Douglas.
The Bay Acres Colonia is currently serviced by inadequate, failing onsite wastewater collection
systems (septic tanks with leach fields). These onsite treatment systems are problematic in Bay
Acres because the residential lots are small and the systems are either failing or near the end of
their useful life. As a result, the small lots do not provide an adequate area for a new or replacement
leach field. In addition, the economic downturn has resulted in many families moving in with each
other and these large households are contributing to system failure. When the septic systems fail,
the lots typically have no room for expansion. To help prevent system failure, at least 25% of the
Bay Acre residences appear to be discharging gray water in their yards to minimize the amount of
water into the onsite systems. Improper gray water techniques and onsite treatment system failure
are resulting in the discharge of inadequately treated sewage, black water, and gray water to streets,
backyards, and alley ways. In some instances, there has been evidence of small children playing
in the ponding from these discharges. The failing on-site wastewater collection systems are a
public health concern due to various pathogenic microorganisms, ammonia and nitrate that may
produce a health risk to humans and degrade the environment.
Currently the Douglas WWTP has flows that are averaging 2.3 MGD and is over the current
permitted capacity of 2.0 MGD. With the connection from the Bay Acres Colonia and other
existing homes along Washington Ave. and 24th Street along, the service flow will be about 2.5
MGD. Therefore, an expansion of 0.6 MGD will be required to accommodate the flows from full
build out of the Bay Acres Colonia. ADEQ requires that a WWTP operate at 85% of its permitted
capacity; thus, with Douglas WWTP operating at approximately 2.5 MGD, the minimum capacity
that the WWTP would be allowed is 3.1 MGD and still comply with Arizona's regulations.
In addition, this project will increase the capacity of the wastewater treatment plant from 2.0 MGD
under Aquifer Protection Permit (#APP-100831) to 3.1 MGD in order to accept and treat flows
from the wastewater collection system expansion and allow for limited and controlled build out of
the City and adjacent areas. The need for increased capacity at the WWTP facility to serve Bay
Acres Colonia triggers a new Aquifer Protection Permit with stricter effluent requirements. These
new requirements necessitate the inclusion of process units for the reduction of effluent nitrogen
concentration as part of the expansion/upgrade. The upgraded treatment process will help meet
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Environmental Assessment
Douglas Wastewater Treatment Plant Upgrade and Bay Acres Colonia Wastewater Collection System Expansion
the Douglas Aquifer Protection Permit requirements and minimum Class B+ effluent standards to
enable the reuse of the effluent on open access landscape areas in the project.
1.3 SCOPE OF ANALYSIS
The scope of this EA includes the evaluation of the impact to the relevant environmental resources
within the defined area of concern in the U.S. As defined in the CEQ regulations (§1508.25), the
scope consists of the range of actions, alternatives, and impacts to be considered in a NEPA-
compliant document.
2.0 PROJECT DESCRIPTION AND ALTERNATIVES
In accordance with Council on Environmental Quality (CEQ) regulations (§1502.14), this section
of the EA: 1) presents and objectively evaluates three alternatives, including the No Action
alternative; 2) devotes substantial treatment to each alternative considered in detail so the
reviewers may evaluate comparative merits; and 3) includes appropriate mitigation measures.
Based on the information and analysis presented in Section 3.0 (Affected Environment) and
Section 4.0 Environmental Consequences), this section also presents the potential environmental
impacts of the alternatives in comparative form, which defines the issues and provides a clear basis
for choice among options by decision makers and the public.
2.1 PROPOSED ACTION
The Proposed Action involves the construction of a wastewater collection system for the Bay
Acres Colonia and expansion and upgrade of the existing Douglas WWTP from 2.0 MGD to 3.1
MGD with treatment to reduce effluent nitrogen concentrations. The proposed upgrade of the
Douglas WWTP would consist of the construction of two oxidation ditches, a secondary clarifier,
lift station, aerobic digester, and an operations and maintenance building. The WWTP
expansion/upgrade will be accompanied by decommissioning of existing components that will no
longer be in use. The proposed expansion/upgrade will fit within the confines of the existing
WWTP footprint. The City of Douglas will seek funding from agencies including the US EPA
through BECC and NADBank, and USDA-RD. This EA will analyze three alternatives, including
the No Action alternative for the Douglas wastewater treatment plant.
The proposed wastewater collection system improvements will be installed to provide wastewater
collection service to the Bay Acres Colonia and immediate surrounding area, which currently rely
on septic tank systems for sewage treatment. Many of the septic systems fail to provide adequate
treatment and need to be replaced. Approximately 370 total units will receive service from the
collection system expansion. Several action alternatives were developed for the wastewater
collection system improvements. This EA will analyze three alternatives, including the No Action
alternative.
Douglas Wastewater Treatment Plant
The existing wastewater treatment plant consists of an activated sludge process with headworks,
two aeration basins, two clarifiers, a belt filter press, chlorination contact chamber, dechlorination,
and concrete sludge drying beds. The existing WWTP currently has a capacity of 2.0 MGD.
According to ADEQ's reclaimed water rating system, the WWTP currently produces an effluent
classified as Class C. The effluent from the WWTP is discharged directly across the border to
Agua Prieta via a 24-inch PVC pipe. The effluent is used primarily for crop irrigation in Mexico.
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Douglas Wastewater Treatment Plant Upgrade and Bay Acres Colonia Wastewater Collection System Expansion
The upgrades to the wastewater treatment plant will be located in the same location as the existing
facility. The site is located in the southwest portion of the City of Douglas. The facility is bounded
to the north and east by private land that was previously used as a smelter facility; to the south by
the US-Mexico border; and to the west by City land.
The proposed WWTP will increase capacity from 2.0 MGD to 3.1 MGD. The proposed WWTP
upgrades will provide treatment for all residents of Bay Acres Colonia, and existing homes along
Washington Avenue and 24th Street, and will meet the existing needs of the City of Douglas plus
consideration for reasonable planned and controlled growth. The need for increased capacity at
the WWTP facility to serve Bay Acres triggers a new Aquifer Protection Permit with stricter
effluent requirements. These new requirements necessitate the inclusion of process units for the
reduction of effluent nitrogen concentration as part of the expansion/upgrade.
It is intended that the treated effluent from the WWTP will continue to be discharged for use in
Agua Prieta, Mexico. The proposed WWTP will be capable of producing a Class B+ effluent.
The Proposed Action includes a lift station, oxidation ditches, clarifier, and an aerobic digester.
Piping modifications to the existing headworks, disinfection contact chamber, Recycle and Waste
Activated Sludge (RAS and WAS) systems, and the belt filter press will also be incorporated into
the proposed improvements. The proposed improvements will be constructed within the existing
facility's footprint. An operation and maintenance building and perimeter security are also being
considered for the proposed improvements.
Bay Acres Wastewater Collection System
The Bay Acres community is located to the northeast of the City of Douglas, just outside of the
City limits and south of Highway 80. The City of Douglas currently provides the residents of Bay
Acres with drinking water service. None of the residents are receiving centralized wastewater
services.
The proposed collection system is expected to connect 318 dwellings within the Bay Acres
Colonia, 32 units along 24th Street, and 20 units in the surrounding area adjacent to Bay Acres, to
the City's centralized wastewater collection system. This amounts to 370 existing sewer services,
producing approximately 103,780 gallons per day (gpd) of wastewater flow. An additional 148
future connections for a total of 508 connections may produce up to 142,764 gpd of sewage within
Bay Acres, and along Washington Avenue and 24th Street, if and when full build-out occurs.
The Proposed Action will require approximately 25,840 linear feet of 8-inch PVC (SDR 35)
gravity sewer pipe, 370 sewer service connections (4-inch lines for laterals) for existing residences,
and 59 sewer manholes. Due to its natural slope in the south-west direction, the proposed
alternative is a gravity sewer system that will not require a lift station. The proposed collection
system would be routed along 24th Street and tie into an existing 8-inch gravity sewer line at Eddie
Avenue and 23rd Street. Septic systems for households connecting to the new centralized
collection system will be properly closed according Arizona Administrative Code (AAC), Title
18, Chapter 9, Section D.
2.2 ALTERNATIVES CONSIDERED - DOUGLAS WASTEWATER TREATMENT
PLANT
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Environmental Assessment
Douglas Wastewater Treatment Plant Upgrade and Bay Acres Colonia Wastewater Collection System Expansion
Alternative 1—No Action
The No Action alternative is intended to be used as the baseline alternative for all the other
alternatives to be compared. No action would result in repeated non-compliance with ADEQ
permit requirements since the WWTP is currently exceeding its plant capacity. The No Action
alternative would most likely result in a compliance action that prevents Douglas from adding
connections to the wastewater collection system. Bay Acres and other customers that have been
issued capacity assurances would need to look at other alternatives to repair failing onsite treatment
systems or provide new services. These compliance actions do not remedy the public health and
environmental threats and are not the preferred alternative for ADEQ, the EPA, the City of
Douglas, or other governmental agencies. The residents of Bay Acres do not have the area on their
properties for new leach fields. Many of the homes take up most of the lot, indicating that the
leach field was installed before the home was built or a leach field was never properly installed.
The No Action alternative does not protect public health or water quality in the Douglas city limits
and surrounding areas. If no action was taken, it would most likely result in significant violations
of the Douglas WWTP's APP permit and potentially an administrative order issued by ADEQ. In
addition to having to pay fines, Douglas would likely also have to pay attorney fees to deal with
the legal ramifications of non-compliance. When the possible violations and monetary fines are
taken into account, the operation cost of non-compliance can exceed the cost of building a new
plant and, in the end, the City would be required to upgrade the WWTP to meet the capacity limits.
igure 2.1: Existing Wastewater Treatment Plant Site Layout (No Action Alternative)
Alternative 2—Aeration Basin
This alternative includes constructing a new larger aeration basin and retrofitting one of the
existing aeration basins to get the needed 3.1 MGD plant capacity. In addition to the aeration
basin, the other existing aeration basin may be retrofitted to function as an anoxic basin for
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Environmental Assessment
Douglas Wastewater Treatment Plant Upgrade and Bay Acres Colonia Wastewater Collection System Expansion
nitrification/de-nitrification process, the smaller clarifier will be decommissioned and a new
clarifier the same size as the existing larger clarifier will be constructed, and a new aerobic digester
should be constructed for biosolids stabilization.
The existing aeration basins are over 30 years old and were constructed of a four-inch wire mesh
with two inches of pneumatically placed concrete. Due to the age and construction method of the
aeration basins, it is unlikely that the basins are watertight. The existing aeration basins may be
lined to mitigate any leakage that occurs. Replacement and/or modifications of the existing basins
will allow the use of more efficient aerati on, having a lower O&M cost.
The existing secondary clarifiers appear to be in good condition; however, they are shallower when
compared to today's standards. This alternative will replace the 50-foot clarifier with a new 77-
foot secondary clarifier that is equal to the size of the larger existing clarifier. Modification can
also be considered for the existing clarifier to improve the efficiency. The smaller secondary
clarifier can then be decommissioned.
All components proposed in Alternative 2 (shown in Figure 2.2) would be compatible should the
plant's capacity be expanded in the future.
Figure 2.2: Aeration Basin Site Layout (Alternative 2)
Alternative 3—Oxidation Ditch
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Environmental Assessment
Douglas Wastewater Treatment Plant Upgrade and Bay Acres Colonia Wastewater Collection System Expansion
The oxidation ditch is an activated sludge process. The oxidation
ditch will be capable of producing high quality effluent because
of the detention time and recirculation of the mixed liquor
suspended solids (MLSS) which gives it the capability of
removing more nitrogen than other activated sludge processes.
The higher quality effluent should have total nitrogen
concentrations within the WWTP's anticipated APP limits. An
oxidation ditch is an oval-shaped basin where MLSS
continuously flow around the oval at a speed of approximately
0.8 to 1.2 ft/s to keep the solids suspended, as shown in Figure
2.3.
The oxidation ditch is a looped system where water travels around the ditch several times before
it is discharged, creating a large internal recycle volume. The high internal recycle can lead to
nearly complete de-nitrification, resulting in low effluent nitrogen concentrations.
Figure
Figure 2.3: Oxidation Ditch
Oxidation Ditch Treatment Plant Site Layout (Alternative 3)
Alternative 4—Sequencing Batch Reactor
The Sequencing Batch Reactor (SBR) is an activated sludge process that operates in a batch mode.
If the SBR is chosen, it would include concrete reactor basins, mixers, waste pumps, and a control
area. The process utilizes a fill and draw reactor with complete mixing during the batch reaction
step; subsequent aeration and clarification steps occur in the same tank. As with other activated
sludge processes, BOD removal, and nitrification and de-nitrification processes are performed in
an SBR system. The SBR process does not require a RAS system like other activated sludge
processes since both aeration and settling occur in the same basin. Treated flow from the basin is
fed to the disinfection system prior to discharge. WAS from the SBR system is fed to digesters
Libduz, tbi in Uis
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Environmental Assessment
Douglas Wastewater Treatment Plant Upgrade and Bay Acres Colonia Wastewater Collection System Expansion
and the belt filter press for solids management. Figure 2.5 depicts the sequencing batch reactor
treatment plant layout.
Proposed
SBR
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Figure 2.5: Sequencing Batch Reactor System Site Layout (Alternative 4)
2.3 ALTERNATIVES CONSIDERED—BAY ACRES COLONIA
Alternative 1 - No Action
The No Action alternative is intended to be used as the baseline alternative to compare all viable
options. The current situation with the failing septic tanks presents an acute risk to human health
and safety. The City of Douglas has been trying for years to alleviate the wastewater issues
currently facing the Bay Acres Colonia, and adjacent areas.
The No Action alternative does not protect public health or water quality. The No Action
alternative would result in the potential for continued leakage of untreated or partially treated
wastewater, exposure of the residents to this public health threat, and possible contamination of
the surrounding area and soil, nearby water wells, and ground water.
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Environmental Assessment
Douglas Wastewater Treatment Plant Upgrade and Bay Acres Colonia Wastewater Collection System Expansion
Alternative 2 - Gravity Wastewater Collection System
This alternative involves discharging the sewage from the Bay Acres Colonia and the adjacent
areas into an existing 8-inch gravity sewer line on 24th Street and Eddie Street. Although the
closest discharge point is actually at a sewer manhole on 23rd Street and Washington Avenue, the
tie-in point on 24th Street and Eddie Street was selected since 24th Street (between Washington
Avenue and Eddie Street) also contains residents with failing septic tank systems. The tie-in will
be to the wastewater collection system within the jurisdiction of the City of Douglas. Initially, the
Bay Acres Colonia is expected to produce approximately 103,780 gpd of sewage with 370 sewer
connections to existing residents. The projected amount of sewage may increase to as much as
142,764 gpd with 508 sewer connections at total build-out.
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Proposed 8" Sewer Line (25,840 L.F.) ' 27th Street
Existing Sewer Line « * 'v
- Flow Arrow
Sanitary Sewer Manholes (59) {fA
Approx. 370 Sewer Services I ^ IB
24th Street
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Environmental Assessment
Douglas Wastewater Treatment Plant Upgrade and Bay Acres Colonia Wastewater Collection System Expansion
to as much as 142,764 gpd with 508 sewer connections projected as in-fill in the Colonia occurs.
The vacuum collection system is shown in Figure 2.7.
The system includes 24,600 linear feet of 4-inch and 2,600 linear of 6-inch PVC pipe. The best
location for the vacuum station was selected to be in the northeast corner of the intersection of 24"'
Street and Washington Avenue. A 6-inch PVC C-900 pressure line will be needed to eventually
discharge to the City of Douglas 8-inch gravity sewer line system. Flows from the project area
will then flow via gravity to the Douglas WWTP.
-
4" VACUUM MAIN
(TYPICAL)
B" VACUUM MAIN
(TYPICAL)
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6" Vacuum Main (2,600 L.F.)
Approx. 370 Sewer Services
Existing 6" Sewer Line
<•* sewer , ¦ ^. ¦: | i -
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Figure 2.7: Vacuum Collection System
Alternative 4 - Aerated Treatment Pond System. This alternative will involve the use of an
aerated treatment pond system. Although the ADEQ may ultimately not approve the use of aerated
ponds, it is presented herein for a streamlined comparison.
Aerated treatment system-type ponds use mechanical or a diffused air system (artificial aeration).
The system of this particular type offers a high efficiency level of oxygen in a one basin module
which is separated in several single treatment steps, such as the BIOWORKS-process.
Consequently the clarifier is embedded as well into this module. The main advantages of this
embedded design are: 1) reduced footprint because of compact construction; 2) waste water is
flowing by gravity through the single process steps and 3) there is no need for interconnecting pipe
or pumps.
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Douglas Wastewater Treatment Plant Upgrade and Bay Acres Colonia Wastewater Collection System Expansion
This system is not a fixed grid aeration system, but instead provides a lateral oscillating motion of
floating air header pipes combined with the suspended OXIWORKS" diffuser allowing free
movement within the bioreactor While the system provides aeration to zones with lower dissolved
oxygen content, it also makes treatment more efficient. The development of the cleaning system
OXIRISE® made the system easier for maintenance. By inserting pressurized air over a special
air distribution system into the diffuser body, each individual diffuser can independently float to
the surface. From there, it can be directly inspected in the boat or removed for other purposes.
Aerated lagoons require less land area and shorter detention times for wastewater than other
lagoons; which is why they are very common in small communities. The aerated treatment pond
system layout is shown in Figure 2.8,
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BAY ACRES COLONIA,
DOUGLAS ARIZONA
LEGEND:
Proposed 8" Sewer Line (25,840 L.F.)
Existing Sewer Line
- Flow Arrow
Sanitary Sewer Manholes (59)
Approx. 370 Sewer Services
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27th Street
[- PROPOSED AERATED
TREATMENT PONDS
(500' x 700" AREA)
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Figure 2.8: Aerated Treatment Pond System
Based on design parameters and specifications from BIOWORKS, a treatment plant of
approximately 1,799 people (build-out amount) requires at least two lagoons in series, with the
first being complete mix and the other being a partial mix. The second lagoon will achieve the 30
mg/1 BOD in the effluent. Each lagoon will have side slopes of 2:1 and about 2 feet of freeboard.
Details of the lagoon size and aeration requirements are listed in Table 2-1.
Ta
)le 2-1. Lagoon Details and Aeration Requirements
Lagoon 1 *
Lagoon 2*
Volume, MGD
0.2
0.2
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Environmental Assessment
Douglas Wastewater Treatment Plant Upgrade and Bay Acres Colonia Wastewater Collection System Expansion
Length x width (at grade), ft
295 X207
294 X 207
SWD, ft
12
12
No. aeration headers
10
4
No. OXIWORKS/header
7
4
SCFM req'd
1,700
400
*BOD and TSS limits of 30 mg/L
Each OXIWORKS assembly will have four tube diffusers for a combined total of approximately
284 tubes. Only one 100 HP blower out of two will be utilized to feed Lagoon 1 with one blower
as a spare. For Lagoon 2, two 25 HP blowers are needed, but one will act as a spare, for a total of
4 blowers. Lagoon 2 could be partitioned off for settling to achieve desired TSS levels. Sludge
production will be assumed at 0.5 pounds per pound of BOD removal.
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Douglas Wastewater Treatment Plant Upgrade and Bay Acres Colonia Wastewater Collection System Expansion
3.0 AFFECTED ENVIRONMENT
The purpose of this section is to describe the environmental resources that could potentially be
impacted by the project alternatives described in Section 2.0. The descriptions of the affected
environment focus on environmental resources located within the proposed project sites and near
the US-Mexican border. Figure 1.2 depicts the areas of interest for the upgrades to the Douglas
WWTP and the Bay Acres wastewater collection system expansion.
The environment setting in the vicinity of the project area consists of a small to medium size
community with a population of approximately 20,000. Douglas is located in the southeastern
corner of Arizona in Cochise County. Douglas is on the US-Mexico International Border adjacent
to the City of Agua Prieta, Mexico. The Project Site is located approximately 119 miles southeast
of Tucson, Arizona in the southern Sulphur Springs Valley of Cochise County.
The Douglas area has a semi-arid climate with hot summer days, moderate winter days, and low
humidity. Average monthly high temperatures range from 62.3° Fahrenheit (F) in January to 95.3°
F in June. Average monthly low temperatures range from 28.9° F in January to 64.2° F in June.
The prevailing wind direction in the Douglas area is from the southeast with mean wind speeds
from 7 to 9 miles per hour. Almost all of the precipitation occurs as rainfall. Precipitation ranges
from 10 to 20 inches per year with an average 14.60 inches per year. Almost half of the rainfall
occurs during the "monsoon" season between June and August. The nearest National Weather
Service (NWS) station is located in Tucson, Arizona.
3.1 LAND USE
Land use within the project site falls into one of six categories: low density residential, medium-
high density residential, commercial, golf course/schools/parks/ irrigation, Douglas Municipal
Airport, and undeveloped.
Infrastructure potentially affected by the project is the existing wastewater collection system and
the wastewater treatment plant. Land planned for the expansion of the wastewater collection
system and the wastewater treatment plant is in already developed and disturbed areas that need to
be connected to City infrastructure.
3.2 SOILS
Cochise County is located entirely within the Basin and Range Province and is characterized by
gently sloping plains broken by rugged mountain ranges. The mountain ranges in southeastern
Cochise County are generally aligned in a north-south direction, and define the boundaries of the
Douglas Basin (Mule Mountains to the southwest, Perilla and Swisshelm Mountains to the east,
and the southern end of the Dragoon Mountains to the north).
Soils within the City of Douglas and other developed areas within the project site are primarily
classified as Libby Gulch complex with inclusions of Ubik and Riveroad soils along drainageways
(NRCS 2012). Other soil types found within the Project Site are Blackeney-Luckyhills and
Forrest-Bonita complexes (NRCS 2012), consistent with local geology. Project area soils tend to
be well-drained with slow to moderately slow permeability rates with the exception of Ubik,
Blackeney, and Luckyhills soils which have moderately rapid permeability rates (NRCS 1999).
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The project site does not contain any farmlands designated Prime and Unique by the USDA-
Natural Resources Conservation Service (USDA-NCRS) (NCRS 1999).
3.3 WATER RESOURCES
Surface Water
The Douglas Basin lies within the Chihuahuan Desert interface with the Sonoran Desert at an
elevation averaging 4,100 to 6,966 feet amsl, and is located between mountain ranges reaching up
to 6966 feet amsl. The basin occupies approximately 949 square miles and is characterized as a
valley flanked by two mountain ranges. It is located in the southeastern corner of Cochise County
and extends from the US-Mexico border northward to the southern end of the Dragoon Mountains
northwest of Elfrida (Arizona Department of Water Resources, 2012).
There is one intermittent stream, Whitewater Draw, located within the basin and near the project
sites. The Whitewater Draw is the primary surface water drainage in the project area. Small
ephemeral washes are also present (AZDWR 2012). Whitewater Draw drains the 949 square mile
Douglas basin in a southerly direction, continuing across the US-Mexico border (AZDWR 2012).
The City of Douglas does not withdraw water from or discharge water to Whitewater Draw.
The two-mile reach of the Whitewater Draw through the project area was perennial until 1976
when it became intermittent after widespread groundwater pumping lowered the regional water
table. Since 1976, Whitewater Draw only flows during summer monsoon season and winter
snowmelt. The annual flow of Whitewater Draw averages 6,730 acre-feet, as measured at US
Geological Survey (USGS) stream gauging station 9537500 "Whitewater Draw near Douglas"
(AZWDR 1997).
Hydrology and Hydraulics
Average annual runoff varies within the basin from 0.2 inches per year in the middle portion of
the basin to 2 inches per year at the northern boundary of the basin (AZDWR 2012).
Wetlands and Waters of the United States
No wetlands or waters of the United States are located within the project area. However, small
palustrine and riverine type wetland habitat may be associated with the Whitewater Draw.
Wetlands are associated with aquatic habitat approximately 25 miles from the project area near the
border with Mexico on the San Bernardino Natural Wildlife Refuge. The Whitewater Draw flows
and is renamed Rio Agua Prieta after crossing the US-Mexico border as part of the Yaqui River.
The Yaqui River eventually drains into the Gulf of California near Guaymas. No construction
would occur within the Whitewater Draw (an intermittent stream) with the proposed project.
Whitewater Draw has designated uses established by the State of Arizona's Water Quality
Standards as aquatic and wildlife (warm water), full body contact, fish consumption, and
agricultural livestock watering (ACC, Title 18, Ch.77). Portions at the headwaters of the
confluence are designated as partial body contact.
Groundwater
The City of Douglas pumps groundwater from the Douglas basin-fill aquifer. The project area is
included within the boundaries of the Douglas Irrigated Non-Expansion Area (INA). Within the
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Douglas basin, irrigation is only allowed on land that was irrigated from 1975 through 1980.
Domestic and municipal water uses are subject to restrictions imposed by the INA classification.
The City of Douglas groundwater records show that the average pumping rate between 2000 and
2011 was 3.86 MGD (4,289 ac-ft/yr). Although, current pumping rates are not readily available,
pumping rates to serve current demand in the project area can be estimated as 4.4 MGD, assuming
a 15 percent loss factor.
According to data from the AZDWR, the measured water levels in the basin-fill aquifer range
between 8 and 402 feet below ground surface. Recorded water levels for Douglas' twenty wells
range from 32 to 283 feet below ground surface.
Total groundwater recharge in the Douglas basin is estimated to be 22,000 ac-ft per year.
Mountain-front precipitation is the main source of groundwater recharge in the Douglas basin at
20,000 ac-ft per year. A small amount of recharge may result from streambed infiltration from the
Whitewater Draw and other ephemeral washes in the basin. Direct recharge from valley floor
precipitation is negligible because high evaporation rates and clay and caliche layers impede
percolation of water.
Floodplains
The majority of the project area is not located within a Federal Emergency Management Agency
(FEMA) Flood Hazard Zone. However, a small portion of the Douglas Wastewater Treatment
Plant and Bay Acres Colonia are located in a Flood Zone A. The Bay Acres collection system will
be constructed underground and will not impact the existing floodplains. For the wastewater
treatment plant, the floodplain is located where existing sludge drying beds are located, thus not
producing additional impacts on floodplains.
3.4 VEGETATIVE HABITAT
The project area is located in the semidesert grassland biotic community, which transitions into
the Chihuahuan Desert scrub community east of Douglas. Vegetation encountered is typical of
the semidesert grasslands consisting of short grasses intermingled with a variety of large, well-
spaced scrub-shrub perennials. Perennial grasses commonly found include black grama
(Bouteloua eriopoda) and other grama species (Bouteloua spp.). Sotols (Dasylirion spp.), agaves
(Agave spp.), yuccas (Yucca spp.), and beargrasses (Nolina spp.) may also be found. Dominant
scrub-shrub species can include mesquite (Prosopis spp.), one seed juniper (,Juniperus
monosperma), grayhorn (Zizyphus obtusifolia, Condalia spathulata), and Mormon or Mexican tea
(.Ephedra trifurca, E. Antisyphilitica). Various cactus species are common. Important species
include barrel cactus (Ferocacutus wislizenii). cane cholla and prickly pears (Opuntia spp.), and
pincushions (Mammillaria spp.).
The Chihuahuan desert scrub community, which borders the semidesert grasslands, is shrub
dominated. Creosote bush (Larrea tridentate), tarbush (Flourensia cernua), and whitehorn acacia
(Accacia neovernicosa) are common. Yuccas, agaves, sotols, and beargrasses are also found in
the Chihuahuan desert community.
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3.5 WILDLIFE RESOURCES
Typical wildlife species found in the semidesert grassland include small mammals such as black-
tailed jack rabbit (Lepus californicus); spotted ground squirrel (Spermophilus spilosoma); Ords,
banner-tailed, and Merriam's kangaroo rats (Dipodomys ordii, D. spectabilis, D. merriami); badger
(Taxidea taxus); and coyote (Canis latrans). Common birds of the semidesert grassland include
Swainson's hawk (Buteo swainsoni); prairie falcon (Falco mexicanus); mourning dove (Zenaida
macroura); scaled quail (Callipepla squamata); road runner (Geococcyx californianus); loggerhead
shrike (Lanius ludovicianus); and meadow lark (Sturnella magna).
Herpetofauna are more prevalent than mammals in the Chihuahuan desert scrub community
bordering the semidesert grassland. Typical species include the Texas banded gecko (Coleonyx
brevis); roundtail horned lizard (Phrynosoma modestum); spiny lizards (Sceloporus sp.); trans-
Pecos ratsnake (Elaphe subocularis); western hooknose snake (Ficimia cana); and Mohave
rattlesnake (Crotalus scrutulatus).
Protected Species and Critical Habitats
Under the Endangered Species Act of 1973, nine endangered species and six threatened species
are found within Cochise County, Arizona (USFWS 1999). In addition, two species proposed for
listing and four candidate species were also identified by USFWS as potentially occurring within
Cochise County; however, no critical habitat for any listed, proposed, or candidate species was
identified within the project area. Threatened, endangered, proposed, and candidate species
identified by the USFWS for Cochise County are as follows:
Endangered Species
Madrean ladies' tresses (Spiranthes delitescens)
Huachuca water umbel (Lilaeopsis schaffneriana ssp. recurva)
Jaguar, United States Population (Panthera onca)
Lesser long-nosed bat (Leptonycteris curasoae yerbabuenae)
Gila chub (Gila intermedia)
Yaqui chub {Gila purpurea)
Yaqui topminnow (Poeciliopsis occidentalis sonoriensis)
Southwestern willow flycatcher (.Empidonax traillii extimus)
Sonora tiger salamander (Ambystoma tigrinum stebbinsi)
Threatened Species
Cochise pincushion cactus (Coryphantha robbinsorum)
New Mexican ridge-nosed rattlesnake (Crotalus willardi obscurus)
Beautiful shiner (Cyprinella formosa)
Yaqui catfish (.Ictaluruspricei)
Mexican spotted owl (Strix occidentalis lucida)
Chiricahua Leopard Frog (Rana Chiricahuensis)
Proposed Species
Lemon fleabane (Erigeron lemmonii)
Huachuca springsnail (Pyrgulopis thompsoni)
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Candidate Species
American peregrine falcon (Falcoperegrinus anatum)
Bald eagle (Haliaeetus leucocephalus)
Sprague's Pipit (Anthus spragueii)
Yellow-billed Cuckoo (Coccyzus Americana)
San Bernardino springsnail (Pyrgulopsis bernardina)
Northern Mexican Garter snake (Thamnophis eques me galops)
3.6 CULTURAL, HISTORICAL, AND ARCHAEOLOGICAL RESOURCES
Cultural resources are any prehistoric or historic district, site, or building, structure, or object
considered important to a culture, subculture, or community for scientific, traditional, religious, or
other purposes. They include archaeological resources, historical architectural resources, and
traditional cultural resources. Only significant cultural resources, as defined in 36 CFR 60.43, are
considered for potential adverse impacts from an action. Significant archeological and
architectural resources are either eligible for listing, or listed on, the National Register of Historic
Places (NRHP).
In accordance with the provisions of the NHPA, EPA consulted with nine Native American
governments with cultural affiliation in southern Arizona to determine whether there are
Traditional Cultural Places in the vicinity of the proposed project or other issues of concern that
need to be addressed. EPA received responses from three tribes. None of these indicated that a
tribe was aware of any historic, religious or culturally significant resources that may be affected
by the proposed project.
In addition, as required by Section 106 of the National Historic Preservation Act, 16 U.S.C.470,
and the Arizona State Historic Preservation Act, A.R.S. §41-861 et seq., a Class III Cultural
Resources Survey of the Bay Acres Colonia and Douglas Wastewater Treatment Plant was
conducted. The survey concluded that work within the project area would not impact historic
properties. (See Appendix A) On December 5, 2013, EPA received concurrence from the Arizona
State Historic Preservation Office of the determination of no adverse effect on historic properties
from the proposed project.
3.7 AIR QUALITY
The EPA established National Ambient Air Quality Standards (NAAQS) for specific pollutants
determined to be of concern with respect to the health and welfare of the general public. Areas
that do not meet these NAAQS are called non-attainment areas. The Federal Conformity Final
Rule (40 CFR Pars 51 and 93) specifies criteria or requirements for determination of conformity
with NAAQS. The Federal Conformity Rule was first promulgated in 1993 by the EPA, following
the passage of Amendments to the Clean Air Act (CAA) in 1990. The rule mandates that a
conformity analysis must be performed when a Federal action generates air pollutants in a region
that has been designated a non-attainment or maintenance area for one or more NAAQS.
EPA is currently finalizing a determination that the Paul Spur/Douglas nonattainment area is now
attaining the NAAQS for PMio, based on certified, quality-assured ambient air monitoring data for
the years 2009-2011. However, pending finalization of EPA's determination, the area in and
around Douglas is still considered in nonattainment of the PMio ambient air quality standard.
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Studies of the particulate emissions indicate that 60% of the PMio in the Douglas area originates
in Mexico. The largest source of PMio was generated from unpaved road dust (81%). The second
largest emission source is agricultural activities (12%). In response to the nonattainment status,
ADEQ has developed a State Implementation Plan (SIP) to address the airborne dust issue and has
submitted this plan to the EPA.
The Paul Spur/Douglas area is also out of attainment for sulfur dioxide (SO2). Historically,
emissions of SO2 in the Douglas area were largely attributed to the Phelps-Dodge Douglas
Reduction Works smelter, which was the major source of SO2 in Douglas until operations closed
in 1987. The smelter had the potential to emit 400,000 tons of SO2 annually, which was over 100
times the total of any current sources combined.
In December, 2005, EPA signed a direct final rule approving Arizona's plan to maintain attainment
of the short-term (24-hour) and long-term (annual) primary NAAQS for Sulfur dioxide (SO2) in
the Douglas area, as well as Arizona's request to re-designate this area from nonattainment to
attainment for SO2. As a formally designated maintenance zone for SO2, Douglas area federal
actions must follow the requirements of the Federal Conformity Rule, as described above.
Odor
There are no odor-producing sources near the Douglas wastewater treatment plant other than the
wastewater treatment plant and associated sludge drying beds. Due to the remote location of the
wastewater treatment plant, no odor problems have been experience in the Douglas area.
3.8 NOISE
Noise is generally described as unwanted sound, which can be based either on objective effects
such as hearing loss or damage to structures or subjective judgments such as community
annoyance. Sound usually represented on logarithmic scale with a unit called the decibel (dB).
Sound on a decibel scale is referred to as sound level. The threshold of human hearing is
approximately 3 dB, and the threshold of discomfort or pain is around 120 dB.
Noise levels occurring at night generally produce a greater annoyance than do the same levels
occurring during the day. It is generally agreed that people perceive intrusive noise at night as
being 10 dBA.
Acceptable noise levels have been established by the U.S. Department of Housing and Urban
Development for construction activities in residential areas: 1) Acceptable (not exceeding 65 dB);
2) Normally Unacceptable (above 65 but not greater than 75 dB); and 3) Unacceptable (greater
than 75 dB).
3.9 ENERGY AND NATURAL RESOURCES
The City of Douglas purchases electricity from Arizona Public Services. The electricity
distribution system appears adequate for the City's current needs as no evidence of brownouts or
other forms of power shortages was identified. Southwestern Gas Corporation provides natural
gas to the City Douglas.
3.10 ROADWAYS AND TRAFFIC
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The wastewater collection system will be installed in public rights-of-way where possible or in
easements. The major roadways that will be affected during construction will include:
Washington Avenue
23rd Street
24th Street
27th Street
34th Street
Pan American Avenue
5th Street
Chino Road
These roadways will be most likely be used as haul routes during construction. Roadway impacts
will be temporary.
3.11 HAZARDOUS MATERIALS
Hazardous materials and substances are regulated in Arizona by a combination of mandated laws
promulgated by the EPA and the ADEQ. A search of Federal and state records for known
hazardous waste sites, potential hazardous waste sites, and remedial activities, including sites that
are on the National Priorities List or being considered for the list. No evidence of hazardous
materials or recognized environmental conditions was detected on-site or near the site during the
field surveys conducted on August 13, 2012.
3.12 SOCIOECONMICS
Population and Demographics
According to the US Census Bureau, the City of Douglas had a population of 14,312 persons and
19,772 persons in 2000 and 2010, respectively. The majority of the growth in population occurred
in 2001 when the City annexed the Arizona Prison Complex-Douglas. The prison complex
increased the City's population by approximately 2,000 residents. In order to accurately model
the population growth in Douglas, the prison population was subtracted from the 2010 census
population for the annual growth rate calculation. The annual growth rate was determined to be
2.189 percent. To project out the population from 2010 to 2035 for the City of Douglas, the
population was projected forward without the prison population. The prison population was then
added to the projected Douglas population to determine flow rates. The Douglas area comprises
the City of Douglas (including the prison), Pirtleville, and surrounding unincorporated areas.
According to the 2010 U.S. Census Bureau American Community Survey, the racial mix of
Douglas consists predominantly of Hispanic. The remainder is divided among African Americans,
Native Americans, Asians, Hawaiian or Pacific Islander, and people claiming to be two or more
races. A small portion of the population self-identifies as multi-racial.
Housing
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The total number of housing units in Douglas was 7,388 in 2010 (Table 3-3), of which 87 percent
were occupied. The majority of these (55.1 percent) were owner-occupied (U.S. Census Bureau).
Comparatively, the owner-occupied housing for the State of Arizona was estimated at 55.2 percent
of the total occupied houses (U.S. Census Bureau).
Table 3-3: Housing Units
Geographic
Region
Total Housing
Units
Status
Occupied
Vacant
Owner
Rented
Douglas
7,388
6,436
2,362
952
Cochise County
59,041
34,711
16,154
8,176
Arizona
2,844,526
1,571,687
809,303
463,536
Income and Employment
In 2008, Douglas had an average household income of $26,579. This was considerably lower than
the countywide median of $43,821 and the statewide income of $51,124. Douglas had an average
per capita income of $13,223 in 2008, compared to $22,160 for Cochise County, and $25,639 for
the state. Data for the county and state are based on the US Census Bureau's 2006-2008 American
Community Survey. Income estimates for Douglas are based on data collected by the US Census
Bureau in 1999, adjusted for inflation to 2008 dollars.
3.13 ENVIRONMENTAL JUSTICE AND PROTECTION OF CHILDREN
The fair treatment of all races has been assuming an increasingly prominent role in environmental
legislation and implementation of environmental statues. In February 1994, President Clinton
signed Executive Order (EO) 12898, Federal Actions to Address Environmental Justice in
Minority Populations and Low-Income Populations. The action requires all Federal agencies to
identify and address disproportionately high and adverse impacts of its programs, policies, and
activities on minority and low-income populations. Cochise County has approximately 31.5
percent of their population claiming Hispanic or Latino origin. Furthermore, Cochise County has
a greater percentage of its population in poverty relative to both Arizona and the Nation.
EO 13045 requires each Federal agency "to identify and assess environmental health risks and
safety risks that may disproportionately affect children"; and "ensure that its policies, programs,
activities, and standards address disproportionate risks to children that result from environmental
health risks or safety risks." This EO was prompted by the recognition that children, still
undergoing physiological growth and development, are more sensitive to adverse environmental
health and safety risks than adults. In Cochise County, about 7 percent of the population is 5 years
old or less and approximately 27 percent is younger than 18 years. The potential for impacts on
the health and safety of children will be slight with increased dust emissions during construction
of the project; however the health benefits of the centralized sanitary sewer collection system will
positively impact the health and safety of children in the area.
3.14 SUSTAIN ABILITY AND GREENING
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In accordance with EO 13423 - Strengthening Federal Environmental, Energy, and Transportation
Management (72 FR 3919), the City of Douglas would incorporate practices in an
environmentally, economically, and fiscally sound, integrated, continuously improving, efficient,
and sustainable manner in support of their mission. CBP implements practices throughout the
agency to: 1) improve energy efficiency and reduce greenhouse emissions, 2) implement
renewable energy projects, 3) reduce water consumption, 4) incorporate sustainable environmental
practices such as recycling and the purchase of recycled-content products, and 5) reduce the
quantity of toxic and hazardous materials used and disposed of by the agency. Additionally, new
facility construction would comply with EO 13514 Guiding Principles for Federal Leadership in
High Performance and Sustainable Buildings set forth in the Federal Leadership in High
Performance and Sustainable Memorandum of Understanding. CBP would also be in compliance
with the Energy Act of 2005 and the Energy Independence and Security Act of 2007 and reduce
total consumption of petroleum products and use environmentally sound practices with respect to
the purchase and disposition of electronic equipment.
3.15 HUMAN HEALTH AND SAFETY
Current health concerns are associated with discharges of raw or inadequately sewage in the
neighborhoods, either from failing septic systems or sewer backups.
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4.0 ENVIRONMENTAL CONSEQUENCES
4.1 LAND USE
Bay Acres
Under the No Action alternative, land use and infrastructure will remain unchanged.
Under the Preferred Alternative and other action alternatives, infrastructure improvements will
increase the number of homes connected to the City's centralized wastewater collection and
treatment system. The areas that are affected are generally developed with mostly residential lots
and a few commercial lots. There are 138 lots that are currently vacant, predominantly within the
Bay Acres Colonia, and it is expected that infill may occur at a faster pace once sewer service is
available, effectively channeling growth into areas that are already disturbed and reducing
pressures to grow the city into areas of open space. These are expected to be the minor long-term
impacts to land use. Short-term impacts from construction will also be minor, and located within
the existing rights-of-way. It is not expected that the construction will have long-term adverse
effect on land use.
Wastewater Treatment Plant
Under the No Action alternative, the Preferred Alternative and the other action alternatives, land
use will remain unchanged.
The proposed site for the Preferred Alternative is at the existing wastewater treatment plant site.
It is not anticipated that additional land will be required when expanding the wastewater treatment
plant; therefore, no adverse direct impacts are expected. Indirect impacts associated with growth
resulting from wastewater treatment plant expansion should be limited to in-fill in already
developed areas.
4.2 SOILS
Bay Acres
Under the No Action alternative, adverse impacts to the soil from failed septic systems will
continue. Furthermore, adverse impacts to soil may increase in the future since new homes in the
Bay Acres Colonia will continue to use septic systems and an upgraded wastewater collection
system will not be available for connection.
The Preferred Alternative and other action alternatives will minimize impacts to soil from failed
septic systems. All current and future residents of Bay Acres and along the gravity collection
system alignment will be connected to the existing Douglas wastewater collection system.
Wastewater Treatment Plant
The No Action alternative may pose an adverse impact to soils at the Wastewater Treatment Plant
site since the older process may leak untreated wastewater into the soil. Additionally, should the
processes fail, there is a potential for a large release of untreated wastewater.
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The Preferred Alternative and other action alternatives for the Wastewater Treatment Plant
upgrades are not expected to generate impacts to the soil. The Wastewater Treatment Plant will
meet water quality standards as directed by the City of Douglas' Aquifer Protection Permit.
4.3 WATER RESOURCES
Surface Water
Bay Acres
The No Action alternative, the Preferred Alternative and other action alternatives are not expected
to have any long-term adverse impacts on surface water quality in the US. In the short-term,
construction of the wastewater collection lines associated with the Preferred Alternative may result
in sediment discharge. Best Management Practices (BMPs) will be used to minimize erosion and
sedimentation around construction areas. Sediment impacts, should they occur, will be temporary
and are not expected to increase annual total suspended solids (TSS) loads over time.
Wastewater Treatment Plant
The No Action alternative is not expected to have any long term adverse impacts on surface water
quality in the US.
The WWTP discharges to community of Agua Preita where it is used for agricultural irrigation.
An increase in the discharge volume from 2.0 mgd to 3.1 mgd would increase the availability of
irrigation water. The water quality would be improved for all action.
Wetlands
Bay Acres
The No Action alternative will not directly or indirectly impact the wetlands or water of the US.
The US Army Corps of Engineers (USACE) administers Section 404 of the Clean Water Act,
governing the placement of dredged or fill material into wetlands and other Waters of the US.
Activities resulting from the project may likely be covered under the Nationwide Permit number
12 with regards to utility line backfilling and bedding. Based on a review of topographic maps,
wetlands have not been identified in the project area.
Wastewater Treatment Plant
The No Action alternative, the Preferred Alternative and other action alternatives will not impact
wetlands or other Waters of the US from any of the activities that are proposed.
Groundwater
Bay Acres
The No Action alternative may have adverse impacts from untreated or inadequately treated
sewage leaking from failed and improperly maintained septic systems that may contaminate the
ground water. In addition, due to the lot sizes and soil conditions within the Bay Acres Colonia,
sufficient land for proper leach fields is not available. Untreated sewage could potentially reach
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the aquifer through the soil or downward movement through poorly cemented groundwater wells
drilled for domestic water supply.
Under the Preferred Alternative and other action alternatives, removal of the septic systems will
eliminate discharges of untreated and inadequately treated wastewater to the environment,
reducing the potential risk to the aquifer from contamination.
Wastewater Treatment Plant
The No Action alternative may have adverse impacts on groundwater from untreated sewage
leaking and contaminating groundwater resources.
The Preferred Alternative and other action alternatives will eliminate discharges of untreated
wastewater to the environment, reducing the potential risk to the aquifer from contamination. The
Preferred Alternative may have positive benefits with the availability of additional treated effluent
to use for irrigation in Agua Prieta, Mexico. The additional effluent available will also reduce the
impacts to groundwater resources in Mexico.
Floodplains
Bay Acres
Portions of the Bay Acres Colonia are in an area designated as a Zone A floodplain, as shown in
the Federal Emergency Management Agency (FEMA) Flood Insurance Rate Maps Nos.
04003C2881F and 04003C2882F, created in August 28, 2008. A Zone A designation indicates
that an area has a 1% annual risk of flooding. However, because wastewater collection system is
underground, there will be no impacts to flood plains.
The No Action alternative, Preferred Alternative, and other action alternatives will not directly or
indirectly impact the floodplains.
Wastewater Treatment Plant
The existing sludge drying beds located within the wastewater treatment plant site are designated
to be within FEMA's Zone A floodplain. Since there will be no change to the existing sludge
drying beds, this alternative will have no impacts to floodplains.
The No Action alternative, Preferred Alternative, and other action alternatives will not directly or
indirectly impact the floodplains.
4.4 VEGETATIVE HABITAT
Bay Acres
The majority of the area affected by the project consists of developed urban or suburban
landscapes. Under these conditions, habitat for native species is typically degraded and where
vegetation exists it is often dominated by non-native plants, and noxious or other weedy species.
These conditions would be expected to continue under the No Action alternative.
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For the Preferred Alternative and other action alternatives, impacts would primarily occur within
existing rights-of-way in areas that have been developed. Impacts to previously undisturbed native
communities would be minimal. Impact to the non-native vegetation within the urban and
suburban areas would likely be short-lived, as reseeding and re-vegetation would occur following
disturbances. Some type of re-vegetation measure is necessary or, there would be an increased
potential for the establishment and proliferation of noxious or other weedy species. If left
unchecked, a weed infestation could spread to native communities causing localized areas of
habitat degradation.
The Federally listed endangered lesser long-nosed bat is found within the project area. At the
recommendation of the U.S. Fish and Wildlife Service, a walk-through was conducted of the
project site to identify the presence of agave plants. Only three agaves were identified when the
field investigation was performed. All three of the agaves were found inside residential home
properties and appear to have been planted by the home owners as an enhancement to their garden.
There are no agaves present within the currently vacant lots or in the open space areas that the
project may potentially impact.
Wastewater Treatment Plant
The project area for the Wastewater Treatment Plant consists of developed light industrial land.
Under these conditions, habitat for native species is degraded and little vegetation exists. Where
vegetation does exist, it is often dominated by non-native plants, and noxious or other weedy
species. These conditions would be expected to continue under the No Action alternative, the
Preferred Alternative and other action alternatives. No agave plants were found within the WWTP
site.
4.5 WILDLIFE RESOURCES
Bay Acres
Since the gravity wastewater collection system construction activity would occur primarily within
previously disturbed area, the proposed activities would have minimal effect on wildlife. The No
Action alternative would maintain the current situation and would thereby not produce any
additional effects. The Preferred Alternative and other action alternatives involve construction of
a wastewater collection system that could potentially affect some wildlife species primarily
through noise and dust. These effects would be limited and short-lived. The impacts would be
limited to existing rights-of-way in urban and suburban areas.
Wastewater Treatment Plant
The proposed improvements to the Wastewater Treatment Plant would occur primarily within
previously disturbed area and would thereby have minimal effect on wildlife. The No Action
alternative would maintain the current situation and would not produce additional effects. The
Preferred Alternative and other action alternatives involves construction of new processes and
decommissioning of existing processes that are no longer used that could potentially affect some
wildlife species, primarily through noise and dust. These effects would be limited and short-lived
as well.
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Protected Species and Critical Habitat
The No Action alternative would maintain the current situation and would thereby not produce
additional effects.
There would not be any adverse effects on threatened or endangered species since these species
and critical habitats have not been documented within the project area. In addition, during a walk-
through of the project site, no protect species or critical habitat was observed.
4.6 CULTURAL RESOURCES
Under No Action alternative, the current situation would continue.
As required by Section 106 of the National Historic Preservation Act, 16 U.S.C.470, and the
Arizona State Historic Preservation Act, A.R.S. §41-861 et seq., a Class III Cultural Resources
Survey of the Bay Acres Colonia and Douglas Wastewater Treatment Plant was conducted. The
survey concluded that work within the project area would not have adverse effect on historic
properties. The Arizona State Historic Preservation Office agreed with the survey's determination.
4.7 AIR QUALITY
PM10 - Under the No Action alternative, no PM10 emissions impacts would be expected. Under
the action alternatives for both the expansion of wastewater collection to Bay Acres and the
upgrade of the WWTP, temporary fugitive dust emissions could be created during construction.
To determine compliance with the General Conformity Rule for PM10, EPA completed a
conformity analysis to estimate the pollutant emission from the proposed action. EPA completed
an emission's inventory for the proposed action, and determined that the PM10 impacts to the Paul
Spur/Douglas nonattainment area from construction activities will be minimal. The inventory,
which was based on conservative estimates of project activity (including but not limited to
trenching, grading, demolition and construction) and EPA's Compilation of Emission Factors
known as AP-42, determined that project-related fugitive dust emissions would range below the
di minimis threshold of 100 tons PMlO/year.
S02 — Under the No Action alternative, no significant S02 emissions impacts would be
anticipated. Under the action alternatives for the expansion of wastewater collection to Bay Acres
and the upgrade of the WWTP, temporary but insignificant emissions of S02 would be generated
during construction due to the combustion of sulfur containing diesel fuels in heavy machinery.
As with the PM10 Conformity Analysis, EPA reviewed the project's emission inventory
estimation for S02. EPA determined that the construction activities associated with the proposed
action project will be minimal and well below the di minimis threshold of 100 tons of S02 per year.
4.8 NOISE
Bay Acres
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The No Action alternative would not result in any increase in noise events since this option would
result in no construction activities.
The action alternatives would be constructed in rural residential/commercial areas. Installation of
the pipeline would require the use of heavy construction equipment. The construction activity has
the potential to expose sensitive receptors to noise levels that are not normally unacceptable at
urban sites. Table 4-1 describes noise emission levels for construction equipment which range
from 70 dBA to 84 dBA (Federal Highway Administration [FHWA] 2007).
Table 4-1: Weighted (dBA) Sound Levels of Construction Equipment and Model Attenuation at Various
Distances
Noise
Source
50 feet
100 feet
200 feet
500 feet
1000 feet
Backhoe
78
72
68
58
52
Dump
Truck
76
70
64
56
50
Excavator
81
75
69
61
55
Front end
Loader
79
73
67
59
53
Concrete
mixer
79
73
67
59
53
truck
Pneumatic
Tools
81
75
69
61
55
Bull dozer
82
76
70
62
56
Generator
81
75
69
61
55
Assuming the worst case scenario of 82 dBA, the noise level would have to travel 500 feet before
it attenuates to acceptable levels of 65 dBA. Common construction equipment can produce noise
levels of 81 dBA, although noise emissions attenuate to normally acceptable levels of 65 dBA,
approximately 300 feet away from the noise source.
The construction activities for the Preferred Alternative would be adjacent to residential properties
and may experience normally unacceptable noise levels (65 to 75 dBA). However, emissions are
expected to be minor and short-term in duration. Construction activities are estimated to last 150
to 180 days. To minimize this impact, construction activities near residential neighborhoods would
be limited to daylight hours during the work week when most of the residents are at school or at
work. Specifically, construction activities will be limited to hours between 7:00 am and 7:00 pm,
Monday through Friday.
During the operational phase of the proposed project, when utilized, backup generators will create
noise levels up to 75 dBA. To minimize noise levels, generators will be equipped with appropriate
sound muffling devices.
Wastewater Treatment Plant
The No Action alternative, the Preferred Alternative, and other action alternatives are not expected
to impose significant long-term noise impacts on the project area. Background noise levels may
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be elevated during construction activities associated the Preferred Alternative. Construction noises
tend to be short in duration and concentrated around immediate work area. Construction related
noise will be mitigated through the use of standard procedures such as specific, weekday hours of
operation and the use of mufflers on construction equipment.
4.9 ENERGY AND NATURAL RESOURCES
Bay Acres
The No Action alternative, the Preferred Alternative, and other action alternatives are not expected
to impose significant positive or negative impacts on the energy supplies and natural resources.
The wastewater collection system flows by gravity and none of the Alternatives will significantly
increase the use of electricity required for lift stations.
Wastewater Treatment Plant
The No Action alternative is not expected to impose significant positive or negative impacts on
the energy supplies and natural resources.
The action alternatives may impose slight impacts to the energy supplies and natural resources
because of the new processes installed; however, these impacts can be minimized by selecting
mechanical equipment that is energy efficient.
4.10 ROADWAY AND TRAFFIC
Bay Acres
The No Action alternative is not expected to impose significant positive or negative impacts on
roadways and traffic.
Implementing the action alternatives would create minor and short-term impacts on roadways and
traffic within the project area. The increase in vehicular traffic would be anticipated due to the
delivery of supply materials and the presence of work crews to the site during the construction
period. The initial construction would include creation of a staging area for materials and
equipment within the project site. Traffic near the construction site would be from construction
workers and material once staging is complete. Long-term impacts on traffic are not expected
from the installation of the Preferred Alternative.
Wastewater Treatment Plant
The No Action alternative is not expected to impose significant positive or negative impacts on
roadways and traffic.
Implementing the action alternatives would create minor and short-term impacts on roadways and
traffic within the project area. The increase in vehicular traffic would be anticipated due to the
delivery of supply materials and the presence of work crews to the site during the construction
period. The initial construction would include creation of a staging area for materials and
equipment within the project site. Traffic near the construction site would be from construction
workers and material once staging is complete. Long-term impacts on traffic are not expected
from the installation of the Preferred Alternative.
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4.11 HAZARDOUS MATERIALS
Bay Acres
The No Action alternative would not involve excavation, so hazardous materials that may be
present in the environment would not be encountered. However, sewage already released into the
environment would remain in place and future releases of sewage from failing septic systems will
continue. The No Action alternative would continue to have adverse impacts that would be
substantially reduced with the Preferred Alternative.
The action alternatives would not involve removal or modification of any known hazardous
materials.
Wastewater Treatment Plant
The No Action alternative would not involve excavation, so hazardous materials that may be
present in the environment would not be encountered. However, sewage already released into the
environment would remain in place and future releases of sewage from aging and under capacity
treatment plant would continue. The No Action alternative would continue to have adverse
impacts that would be substantially reduced with the Preferred Alternative.
Under the Preferred Alternative, the quantity of sludge generated by the wastewater treatment plant
is expected to decrease with the addition of an aerobic digester. Even though the amount of
wastewater being processed will increase, the digester will reduce the amount of dry solids
produced. Furthermore, the dry solids will be stabilized reducing the number of pathogens and
vectors associated with the dry solids. Sludge composition is not expected to change significantly
as most new users will be residential.
4.12 SOCIOECOMICS
Bay Acres
The No Action alternative may have a negative economic impact on individuals not currently
connected to the municipal wastewater collection system. These individuals may have to pump
septic systems on a regular basis to prevent failure. Also, septic system owners must absorb the
full cost of repairing or replacing their septic systems in the future.
Under action alternatives, property owners will be charged for wastewater service, although these
new costs will be offset by the elimination of the costs associated with maintenance and
replacement of septic systems. In addition, property owners may experience an increase in
property values by being connected to the municipal wastewater collection system. Indirectly, the
Preferred Alternative should improve economic opportunities for project area residents by
providing reliable sewer service to businesses and households. Population growth may be slightly
accelerated as a result of improved services within the project area.
Wastewater Treatment Plant
The No Action alternative may have a negative socioeconomic impact for both individuals
currently on septic systems and the City of Douglas. Without the expansion of the wastewater
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treatment plant, the City will not be able to extend treatment service to the Bay Acres Colonia and
to properties within the City of Douglas.
The action alternatives will provide the capacity needed to extend sewer service to the Bay Acres
Colonia and provide capacity for growth within the City of Douglas. Current septic users will be
able to curtail use of septic systems and avoid the costs associated with maintenance and
replacement of failed systems by being on the municipal sewer system. Indirectly, the Preferred
Alternative should improve economic opportunities and growth for project area residents by
providing reliable sewer service to businesses and households.
4.13 ENVIRONMENTAL JUSTICE AND PROTECTION OF CHILDREN
No disproportionately-high or adverse environmental health or safety impacts on minority or low-
income populations or children would be expected with any of the project alternatives.
4.14 SUSTAIN ABILITY AND GREENING
Bay Acres
The No Action alternative would not result in any direct or indirect impacts, as no construction
activities would take place.
Under the Preferred Alternative and other action alternatives, greenhouse emissions and energy
consumption would be minimized since the wastewater collection system will be gravity.
Therefore, no major adverse impacts are expected to occur as a result of the Preferred Alternative.
Wastewater Treatment Plant
The No Action alternative would not result in any direct or indirect impacts, as no construction
activities would take place.
Under the Preferred Alternative and other action alternatives, greenhouse emissions and energy
consumption will be closely monitored to incorporate equipment and processes that realize the
opportunities for sustainability.
4.15 HUMAN HEALTH AND SAFETY
Bay Acres
The No Action alternative results in a continuation of public health and safety concerns within the
project area. Without proper maintenance, septic systems will continue to fail.. The lot sizes
typically found in the project area do not have extra room for the replacement of septic tank
systems and this may continue to result, as it has in the past, in sewage overflows coming from the
septic tanks and reaching backyards and the surrounding streets.
The action alternatives provide the most positive benefits to public health and safety. Under the
Preferred Alternative, residents of the Bay Acres Colonia and the residents adjacent to the
collection system alignment will be connected to the sewer system. Under the Preferred
Alternative, the City will be able to ensure that all project area residents have access to a public
wastewater collection system.
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Wastewater Treatment Plant
The No Action alternative results in a continuation of public health and safety concerns within the
project area. Without the expansion of the wastewater treatment plant, the City of Douglas will
not be able to extend service to the Bay Acres Colonia and future infill development will be
restricted. The effluent that the wastewater treatment plant produces will continue to be a Class
C, greatly limiting the uses.
The action alternatives provide the most positive benefits to public health and safety. Under the
Preferred Alternative, the treatment plant will be able to extend service to the Bay Acres Colonia
and other residents along the new collection alignment. The effluent that is produced from the
treatment plant will be a Class B+, which offers more opportunities for reuse.
4.16 CUMULATIVE EFFECTS
CEQ defines cumulative impacts as an "impact on the environment which results from the
incremental impact of the action when added to other past, present, and reasonably foreseeable
actions regardless of what agency or person undertakes such other actions" (40 CFR 1508.7).
Cumulative impacts can result from individually minor but collectively significant actions taking
place over a period of time by various agencies or individuals. Informed decision-making is served
by consideration of cumulative impacts resulting from projects that are proposed under
construction, recently completed, or anticipated to be implemented in the reasonably foreseeable
future.
The Preferred Alternative would accommodate the addition of 138 new homes within the service
area. Currently, there are no other development plans in the nearby area that would have a
cumulative effect in the environment.
The combination of the alternatives and the improvements to the Douglas wastewater treatment
plant is expected to generate positive cumulative impacts. Currently, septic conditions exist in the
Rio Agua Prieta because of the river's flat gradient, warm air temperatures, occasional overflow
from Douglas' secondary clarifier, and illegal sewage discharges originating in Mexico.
Upgrading the WWTP and improving the water quality of the effluent will improve the water
quality of the Rio Agua Prieta.
The quality of water discharged by the Douglas wastewater treatment plant to Agua Prieta is
expected to improve with the installation of a new secondary clarifier and the issuance of a new
APP by the ADEQ. The proposed improvements at the wastewater treatment plant require an
Aquifer Protection Permit (APP) from the Arizona Department of Environmental Quality
(ADEQ). The City of Douglas will need to submit monthly discharge monitoring reports to ADEQ
to ensure that water quality standards are not being violated (AAC Title 18, Ch. 9). Additionally,
effluent turbidity cannot exceed one nephelometric turbidity unit based on a monthly average
(AAC Title 18, Ch. 11); low turbidity is indicative of an efficient treatment process. The
combination of improvements to the wastewater treatment plant and compliance with the APP are
expected to significantly and consistently improve the quality of Douglas' effluent and have a
positive effect on odors in Mexico.
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The cumulative environmental impacts from the Preferred Alternative are positive. The City of
Douglas is in the process of constructing improvements to the municipal wastewater treatment
plant. The combination of an improved wastewater treatment plant with the expanded wastewater
collection system is expected to result in increased, higher quality discharges to the Rio Agua
Prieta. Increased surface water flows can be used by Mexican irrigators and potentially reduce
groundwater withdrawals. Higher flow levels have additional environmental benefits, including
dilution of other sources of water pollution in Mexico and in-stream flows for aquatic and
terrestrial wildlife.
The City of Douglas has considered implementing a Wastewater Reuse Program at some point in
the future. The Reuse Program will allow for the reduction of groundwater withdrawal from the
Douglas-Agua Prieta basin. Water reuse eliminates the need for additional water wells for
irrigation purposes. This program would use treated effluent to irrigate the golf course, airport,
and other public spaces. The reuse project, however, is not part of the BECC project certification
package.
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APPENDIX A - Class III Cultural Resources Survey
Douglas, Arizona
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