NC0090239_Other_20230508

Engineering Alternatives Analysis (EAA) Guidance Document
North Carolina Division of Water Resources
NOTE: The N.C. Division of Water Resources (DWR) will not accept an NPDES application for a new or
expanding wastewater treatment plant discharge unless all the required application requirements are
submitted. A complete NPDES application will include the following items:
NPDES Application Form (in triplicate)
Application Fee
Engineering Alternatives Analysis (in triplicate)
Local Government Review Form (non -municipals only)
Failure to submit all of the required information will result in return of the incomplete package. If you have
any questions about these requirements, contact the NPDES Unit staff. Contact names, application forms,
applicable fees, and guidance documents are available on the NPDES website at:
https: deq.nc.gov/about/divisions/Nvater-resources/water-resoumes-perm ts/Nvastewater-branch/nl2des-wastewater-permits.
Completed applications should be mailed to: NCDENR/DWR/NPDES Complex Permitting Unit,1617 Mail
Service Center, Raleigh, NC 27699-1617.
Background
The NPDES permit program was enacted in 1972 as part of the Clean Water Act. The original goal of the program
was to eliminate all point source discharges to surface waters by 1985. Although this goal was not achieved, the NPDES
program continues to strive toward it. In that light, an Engineering Alternatives Analysis (EAA) is required with
any NPDES application for a new or expanding wastewater treatment plant discharge, in accordance with 15A
NCAC 2H.0105(c)(2). In order for an NPDES application to be approved, the FAA must provide complete
justification for a direct discharge to surface water alternative, and demonstrate that direct discharge is the most
environmentally sound alternative selected from all reasonably cost-effective options (per 15A NCAC 2H.0105(c)(2)].
The purpose of this EAA Guidance Document is to provide guidance to the regulated community for die evaluation of
wastewater disposal alternatives. The impetus behind this comprehensive guidance was based on the following: 1) a
majority of new NPDES applications were being returned as incomplete due to inadequate FAA submissions; and 2) a
few recent court cases resulted in unfavorable rulings for the NPDES discharger due in part to inadequate EAAs. DWR
most frequently returns EAAs as incomplete due to inadequate flow justification, inadequate alternatives evaluations,
and/or lack of documentation/references used to design and cost alternatives.
Please note that this guidance document is designed primarily for domestic wastewater discharges. For other proposed
discharges such as water treatment plant discharges from ion exchange and reverse osmosis units, some alternative
disposal options may not be technologically feasible. Within this guidance document, we have attempted to point out
where such technological limitations may exist. You are urged to review NPDFS permitting guidance documents on the
NPDES website, which discuss some of the limited disposal options for some discharges.
Please note that if a proposed municipal expansion is subject to SEPA Environmental Assessment (FA)/Environmental
Impact Statement (EIS) requirements, the FAA requirements should be incorporated into the SEPA document. In
addition, the NPDES Unit cannot accept an application fox a new/expanding NPDES discharge until departmental
review of the SEPA document is complete and a Finding of No Significant Impact (FONSI) has been submitted to the
State Clearinghouse for circulation.
The following step-by-step outline should be used for the preparation of all FAA submissions. If an FAA submission
lacks any of these basic elements, the NPDES application will be returned as incomplete.
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STEP 1. Determine if the proposed discharge will be allowed
Before beginning any engineering evaluation of alternatives, you must first determine if the proposed wastewater
discharge will be allowed. Otherwise, time and money maybe spent needlessly for an EAA preparation that will ultimately
be rejected on the basis of existing water quality restrictions. There are several potential restrictions to a wastewater
discharge to surface waters, including:
• Zero flow stream restrictions [15A NCAC 2B.0206(d)(2)] apply to oxygen -consuming waste in zero -flow
streams. In order to determine streamflow at the proposed discharge location, contact the U.S. Geological
Survey at919-571-4000.
• Receiving stream classification restrictions [e.g., ORW, WS, SA, NSW, and HQ class waters have various
discharge restrictions or require stricter treatment standards]. Stream classifications are available on the
the D\XVR Classification and Standards/Rule Review Branch website:
(http://portal.ncdent.org/web/wq/ps/csu), while wastewater discharge restrictions for various stream
classifications are presented in state regulations [ 15A NCAC 2B.0200].
• Basinwide Water Quality Plans. These basin -specific plans list NPDES permitting strategies that may limit
wastewater discharges to particular streams within the basin due to lack of stream assimilative capacity, etc.
Basin plans are available on the DWR Nvebsite, or you may contact the DWR Basinwide Planning Branch
Oittp://portal.ncdenr.org/web/wq/ps/bpu)..
• Impaired waters and TMDLs. Certain waterbodies listed as impaired on the 303(d) list and/or subject to
impending TMDLs may have wastewater discharge restrictions. The list of 303(d) impaired waters is
located on the DWR website, or you may contact the DWR Modeling and Assessment Branch
Oittp://portal.ncdcar.org/web/wq/ps/mtu).
• Presence of Endangered Species. If endangered species are present in the proposed discharge location,
there may be wastewater discharge restrictions. Endangered species information may be included in the
Basinwide Water Quality Plan, or you may contact the U.S. Fish and Wildlife Service (919-856-4520), N.C.
Wildlife Resources Commission (919-733-3633), or the N.C. Natural Heritage Program (919-733-7701).
Municipal applicants.
As a public service, the NPDES Unit will evaluate whether a proposed municipal discharge is considered allowable. The
municipality needs to initiate thus review by submitting a letter request for Speculative Effluent Limits to the NPDES
Unit. You must obtain streamflow estimates for the proposed discharge location to ensure that the receiving stream is
not subject to zero flow restrictions. Low flow data (specifically, drainage area, summer and winter 7Q10, average flow
and 30Q2 flow statistics) can be obtained for a nominal fee from the U.S. Geological Survey in Raleigh at 919-571-4000.
The low flow data must be submitted with the speculative limits request letter. If the proposed discharge appears to be
allowable, the NPDES Unit will prepare speculative effluent limits for a maximum of 2 flows and 2 discharge locations
using water quality models. The municipality can then use the speculative limits to prepare preliminary engineering design
and cost estimates for the direct discharge alternative within the FAA. In limited instances where complex water quality
models are necessary to develop speculative limits and determine potential water quality impacts, some municipalities
have undertaken the modeling effort (with DWR review) in order to expedite this portion of the NPDES permit review
process.
Non -municipal applicants.
Due to staff constraints, the NPDES Unit cannot prepare speculative limits for non -municipal applicants. Thus, it is
your responsibility to make your own determination as to whether the proposed discharge might be allowed by the
Division, by evaluating the water quality factors listed above. It is highly recommended that you discuss the proposed
discharge with the applicable DWR Regional Office and/or NPDES Unit staff, who may be able to provide input on the
likelihood of a new/expanding discharge. As a first step, you must obtain streamflow estimates for the proposed
discharge location to ensure that the receiving stream is not subject to zero flow restrictions. Low flow data (specifically,
drainage area, the summer and winter 7Q10, average flow and 30Q2 flow statistics) can be obtained for a nominal fee
from the U.S. Geological Survey in Raleigh at 919-571-4000. The low flow data must be submitted with the EAA, and
will be used by the permit writer to develop permit limits. You must also verify that the proposed action (i.e., construction
of a wastewater treatment plant and its appurtenances) is consistent with local zoning and/or subdivision ordinances.
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You will need to request the local government(s) to complete a Local Government Review Form (Attachment A), and
include the signed and notarized form with your NPDES application package.
All applicants.
If you conclude that the proposed discharge will pass the "allowable discharge" criteria, then begin the F.AA preparation
by summarizing the following general information about the proposed project:
• Provide a description of the proposed project. If the project will be constructed in phases, provide a
schedule for constructing each additional phase, and provide the projected flow per phase (see STEP 2).
• Applicant name, mailing address, phone number, contact person
• Facility name, address, county, phone number, contact person
• FAA preparer's name, mailing address, phone number, contact person
STEP 2. Provide reasonable projections for population and flow
Residential Population Projections.
Facilities requesting an NPDES discharge permit for new or expanding domestic wastewater discharges must document
the population to be served within the service area over a 20-year planning period. The NC State Demographics unit
provides population data for each county and municipality and can be accessed on the Internet at
http://www.demog.state.nc.us. If 20-year population projections for specific areas are not available, a linear
extrapolation of population tends from the past decade should be used. Any deviation from a linear projection method
must be clearly justified. If population projections include future annexations, include a proposed annexation schedule
as well as any annexation requirements that must be met.
Municipal Flow Projections.
justification of flow as well as a demonstration of need shall be provided. Mere speculation is not sufficient. Flow
projections should represent average anticipated flows, since permit flow limits are based on monthly averages. Peaking
factors used to design various components of the wastewater collection system (e.g., collector sewers, interceptor sewers,
pumping stations) should not be used in the justification of the average anticipated flow. For municipal wastewater
dischargers, flow must be justified using the Clean Water Loan Program (CWLP) Guidance for Preaparing Engineering
Reports available on the Internet at http://portal.ncdenr.org/web/wi/cleanNvater/er. Exceptions to these flow criteria
may be approved on a case -by -case basis provided adequate justification is supplied.
• Current Flow- Provide current flows including residential, commercial, industrial, and infiltration/inflow
(I/I) based on actual flow data or water billing records. Current residential flow and current commercial
flow may be based on water billing records minus a 10% consumptive loss. Current industrial flow may
be based on dual metering to determine consumptive losses.
• Future Residential Flow- Provide 20-year residential flows based on projected residential growth. Multiply
the projected growth in residential population by 70 gallons per day per capita.
• Future Commercial Flow- Provide 20-year commercial flows based on projected residential growth.
Multiply the projected growth in residential population by 15 gallons per day per capita.
• Future Industrial Flow- Provide flow for future documented industrial flow. A nominal allowance for
future unplanned industrial expansions may be considered by the Division, provided the basis is clearly
justified and current land -use plans and local zoning allow for such industrial growth.
Non -Municipal Flow Projections.
Flow may be justified in accordance with 15A NCAC 2H .0219(1) for various activities (e.g., new subdivisions, new
schools, various commercial activities). For other proposed discharges (e.g., groundwater remediation, water treatment
plant filter backwash, industrial facilities), the flow projections will be based on engineering design considerations
and/or production projections rather than population projections.
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STEP 3. Evaluate technologically feasible alternatives
Since a goal of the Clean Water Act is to minimize or eliminate point source discharges to surface waters, any proposal
for a new or expanding wastewater discharge must include evaluation of wastewater disposal alternatives in addition to
direct discharge. Particularly for dischargers of domestic wastewater, this evaluation should investigate the feasibility of
the following wastewater disposal alternatives:
■ Connection to an existing wastewater treatment plant (public or private)
• Land application alternatives, such as individual/community onsite subsurface systems, drip irrigation,
spray irrigation
• Wastewater reuse
• Surface water discharge through the NPDES program
• Combinations of the above
In order for the applicant to eliminate a wastewater disposal alternative, you must either show that the alternative is
technologically infeasible, or that it Nvould be cost prohibitive to implement relative to a direct discharge alternative.
Please note that for some alternatives, it might be easier to prove an alternative is not viable based on high cost rather
than technological feasibility. For example, for a large municipal expansion that would require several hundred acres for
a land application alternative, it might be easier to simply assume that the required acreage could be purchased and
calculate the present value costs (including current market land costs) for this option, rather than evaluating whether land
application is technologically infeasible due to lack of available land and/or poor soil conditions. For those alternatives
identified as technologically feasible, you must develop and compare costs, based on a preliminary level design effort (see
STEP 4).
The Division recognizes that wastewater disposal alternatives may be limited for some non -domestic wastewater
scenarios, and a full alternatives evaluation may not be warranted. If there is some question as to whether an alternative
may be eliminated, contact the NPDES Unit staff. Some scenarios that might not require a full alternatives evaluation
include:
Water Treatment Plant Discharges. Discharges from water treatment plants (%TPs) that utilize a
membrane technology (e.g., reverse osmosis, nanofiltration) or ion exchange system tend to generate highly
concentrated wastestreams. These wastestreams are not amenable to land application and do not have to
be evaluated for this alternative. However, since these wastestreams can also have a toxic impact on a
receiving freshwater system, proposed new discharges from these WT?s to freshwaters -,vill not be
considered for an NPDES permit unless you can demonstrate that the environmental impacts would be
minimal based on dilution modeling. You should investigate whether the wastewater can be piped to a
stream with sufficient dilution, or whether a local W WIP might accommodate this discharge. Please note
that discharges from WIT's that utilize greensand filtration or conventional technology produce a
wastestream that is not saline, therefore no disposal alternatives can be automatically ruled out as infeasible
for these other WIPs. Refer to the NPDES website for permitting strategies for reverse osmosis, ion
exchange, greensand filtration, and conventional XC TPs.
Groundwater Remediation System Discharges. You will need to evaluate whether NMI? connection, land
application, infiltration galleries, in -situ groundwater remediation wells, or closed -loop groundwater
remediation wells are viable disposal alternatives. While land application might be a feasible alternative in
rural areas, it would not be a feasible alternative in downtown Charlotte, where there is no land available
for wastewater application. In this instance, you may simply state that land application is infeasible based
on land constraints within the city. You will also need to evaluate connection to an existing W VTP (in
accordance with Alternative A), since there are some municipalities that have accepted this wastestream in
the past. If the municipality will not accept the wastestream, the connection alternative is also considered
technologically infeasible. Please note that in -situ and closed -loop groundwater remediation wells are
permittable well types and further guidance is available through the Aquifer Protection Section.
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Aside from these exceptions, you should proceed with the alternatives evaluation in accordance with die following
requirements. If you have any questions about these requirements, contact the NPDES Unit staff.
Alternative A. Connection to an Existing Wastewater Treatment System.
You must evaluate the feasibility of connecting to an existing wastewater treatment system served by a municipality or
other entity holding a valid NPDES or Non -Discharge Permit. All connection options should include an evaluation of
a gravity line and/or force main with pump station(s).
1. Existing Sewerage System:
(a) Identify whether there are existing sewer lines within a five -mile radius, or consider a greater radius if
cost effective for tine project size.
(b) Provide a preliminary indication of flow acceptance from existing municipal or private XVWTPs under
consideration for connection. If a municipal or private VAVrP cannot accept the wastewater, include
a letter documenting such and consider this alternative technologically infeasible.
(c) If an existing sewerage system will accept the wastewater, evaluate the piping/ptunps/resources
necessary to connect to the existing wastewater treatment plant. Attach a topographic map or a site
drawing showing the physical route of this alternative. Conduct a Present Value Cost Analysis per
STEP 4.
2. Planned Sewerage System: Determine if a regional sewerage system within a five mile radius is projected to
be available within the next five years to receive waste from the project site. If applicable, determine
availability date and flow acceptance projection from appropriate authority.
Alternative B. Land Application.
Land application disposal alternatives include individual/community onsite subsurface systems, drip irrigation, and
spray irrigation.
1. Provide an estimate of the best case hydraulic loading rate based on County Soil Surveys or from a soil
evaluation performed by a soil scientist. Include calculations showing the hydraulic loading rate and
the total area of land needed for the land disposal system, including buffers.
2. Assess the availability of land. If insufficient land is available onsite, assume that the necessary land can be
purchased and estimate the land purchase cost based on local real estate prices. Alternatively, provide
documentation to demonstrate that insufficient land is available for sale in the project area (include letters
from adjacent property owners indicating no interest in selling property).
3. Provide a description of the wastewater treatment system and the non -discharge application system.
Include a site plan showing the proposed layout, the application area, any existing structures, proposed
structures, and other uses within the site.
4. Explain the proposed reuse plan if reclaimed water will be used by a third party.
5. Conduct a Present Value Cost Analysis per STEP 4. For the reclaimed water system include the potential
revenue generated by selling the water.
6. Provide all calculations, documentation and maps as necessary to support assumptions and conclusions.
7. Note: The design of land application systems must meet the treatment and design requirements specified
in 15A NCAC 2T .05 or 15A NCAC 18A.1900.
8. Note: Proposed discharges from groundwater remediation systems must evaluate the potential for an
infiltration gallery treatment alternative.
Alternative C. Wastewater Reuse.
You must evaluate reusing all or a portion of the wastewater generated. Some municipalities are currently reusing
wastewater within the confines of their VAMP property for irrigation, toilet flushing, backwaslvng, etc., while other
municipalities have established progressive reuse programs for residential irrigation. Reuse applications might include
golf course irrigation, crop irrigation (e.g., hardwood or pine plantation, grasses), athletic field irrigation, landscape uses,
and commercial/industrial uses. Some of these reuse applications Nvill be evaluated under Alternative B, Land
Application. The design of reclaimed water systems must meet the treatment and design requirements specified in 15A
NCAC 2U.
Alternative D. Direct Discharge to Surface Waters.
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1. No new or expanding (additional) discharge of oxygen -consuming waste will be allowed to surface waters
of North Carolina if both the summer 7Q10 and 30Q2 streamflows are estimated to be zero, in accordance
with 15A NCAC 2B.0206(d). Private applicants must contact the USGS in Raleigh at 919-571-4000 and
obtain (generally for a nominal fee), the receiving streatnflow data (s7Q10, 30Q2, annual average
streamflow) at the proposed discharge location. This information must be included in the FAA, and will
be used to develop permit limits.
2. All direct discharge systems of oxygen -consuming wastes should be evaluated both with tertiary filtration
[BODS= 5 mg/l, NH3-N= 1 mg/1] and without, and assuming a weekly sampling regime.
3. Provide a description of the proposed wastewater treatment facilities, including a schematic diagram of the
major components and a site plan of the treatment facility with outfall line(s).
4. Provide documentation of the availability of required land and/or easement agreements.
5. Conduct a Present Value Cost Analysis per STEP 4.
6. Note: All direct discharge treatment systems must comply with Reliability Requirements specified in 15A
NCAC 2110124.
Alternative E. Combination of Alternatives.
You should evaluate the possibility of a combination of wastewater alternatives that would minimize or eliminate a
direct discharge alternative. For example, consider whether the facility can operate a land application system during the
dry season when streamflows are at their lowest and provide less dilution, and operate an NPDES discharge system
during the wet season when soils may not be as amenable to land application and the receiving stream provides its
greatest dilution.
STEP 4. Evaluate economic feasibility of alternatives
To provide valid cost comparisons among all technologically feasible wastewater alternatives identified in STEP 3, a 20-
year Present Value of Costs Analysis (PVCA) must be performed. A preliminary design level effort is considered
appropriate for comparing feasible options and their associated costs. For the PVCA cost comparison, all future
expenditures are converted to a present value cost at the beginning of the 20-year planning period. A discount rate is
used in the analysis and represents the time value of money (the ability of money to earn interest). Present value is also
referred to as "present discounted value" or "present worth".
The PVCA should include all monetary costs associated with construction, startup and annual operation and
maintenance of a facility. All unit cost information must be provided, and costs must be referenced. Costs can be
referenced in paragraph format by summarizing the sources utilized (e.g., vendor quotes, realtor land quotes, past bids,
Means Construction Index, etc). Vender quotes received for treatment units or other components, as well as realtor
land quotes, shall be included as well. For each treatment alternative identified as technologically feasible, costs should
include, but not be limited to, the following.
Capital Costs
• Land acquisition costs
• Equipment costs
• Labor costs
• Installation costs
• Design costs
Recurring Costs
• Operation and maintenance costs (with replacement costs)
• Laboratory costs assuming a weekly monitoring regime for discharge systems and a monthly regime for
non -discharge systems
• Operator and support staff costs
• Residual disposal costs
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Connection fees and subsequent user fees
Permit and compliance fees
Utility costs (power, water, etc.)
Lost Opportunity Costs
PVCA Calculation Method.
The following standard formula for computing the present value must be used in all cost estimates made under this
evaluation:
NNhere:
PV= Co
+� C'
=i (1+r)'
PV = Present value of costs.
Co = Costs incurred in the present year.
Ct = Costs incurred in time t.
t = Time period after the present year (The present year is t = 0)
n = Ending year of the life of the facility.
r = Current EPA discount rate. EPA adjusts this rate annually on October 1, and it can be accessed from
the Internet at http:/Nvww.nccgl.net/fap/aysrf/201gui.html.
If recurring costs are the same in years I through 20, then Ct=C and the formula reduces to:
PV=C +
As an example, assuming capital costs (Co) of $2 million, annual recurring costs (C) of $40,000, and a discount rate (1)
of 5.625%, the 20-year (n=20) present value of costs would equal:
PV= capital costs + recurring costs X
PV= $2,000,000 + $40,000 X
PV= $2,000,000 + $471,428
PV= $2,471,428
[(1+0.05625)20 — 1] / [0.05625(1+0.05625)20]
[1.98/0.168]
PVCA Summary Table.
The FAA must include a Summary Cost Table, which summarizes present worth costs developed for all technologically
feasible wastewater alternatives. The summary should include a breakdown of capital costs and recurring costs. In some
situations, the Division may require the applicant to refine cost estimates for some alternatives, or possibly collect actual
soil data to better characterize the land application alternative. Ultimately, the final determination on cost effectiveness
is made by the Division with consideration of monetary costs as well as potential environmental impacts.
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Attachment A. Local Government Review Form
General Statute Overview: North Carolina General Statute 143-215.1 (c)(6) allows input from local governments in the issuance
of NPDES Permits for non -municipal domestic wastewater treatment facilities. Specifically, the Environmental Management
Commission (EMC) may not act on an application for a new non -municipal domestic wastewater discharge facility until it has
received a written statement from each city and county government having jurisdiction over any part of the lands on which the
proposed facility and its appurtenances are to be located. The written statement shall document whether the city or county has a
zoning or subdivision ordinance in effect and (if such an ordinance is in effect) whether the proposed facility is consistent with the
ordinance. The EMC shall not approve a permit application for any facility which a city or county has determined to be inconsistent
with zoning or subdivision ordinances unless the approval of such application is determined to have statewide significance and is
in the best interest of the State.
Inshucfions to the Applicant: Prior to submitting an application for a NPDES Permit for a proposed facility, the applicant shall
request that both the nearby city and county government complete this form. The applicant must:
• Submit a copy of the permit application (with a written request for this form to be completed) to the clerk of the city and
the county by certified mail, return receipt requested.
• If either (or both) local government(s) fail(s) to mail the completed form, as evidenced by the postmark on the certified mail
cud(s), within 15 days after receiving and signing for the certified mail, the applicant may submit the application to the
NPDES Unit.
• As evidence to the Commission that the local government(s) failed to respond within 15 days, the applicant shall submit a
copy of the certified mail card along with a notarized letter stating that the local government(s) failed to respond within the
15-day period.
Instructions to the Local Government: The nearby city and/or county government which may have or has jurisdiction over any
put of the land on which the proposed facility or its appurtenances are to be located is required to complete and return this form
to the applicant within 15 days of receipt. The form must be signed and notarized.
Name of local
Concord, North Carolina
(City/County)
Does the city/county have jurisdiction over any part of the land on which the proposed facility and its appurtenances are to be
located? Yes [X] No [ ] If no, please sign this form, have it notarized, and return it to the applicant.
Does the city/county have in effect a zoning or subdivision ordinance? Yes [X] No [ ]
If thereis
as zoniinng' or subdivision ordinance in effect, is the plan for the proposed facility consistent with
�the
^ordinance?
/Yes [X]
Date ]"//ram Signature_
(City Manager ounty Man ger)
State off f� / / it (J ITI/y%�.�(i , County of LWK6AV%�%'ts
On this �V ' v " day of , _, personally appeared before me, the said
name Lloyd Wm. Payne to me known and known to me to be the person described in
and who executed the foregoing document and he (or she) acknowledged that he (or she) executed the same and being duly sworn
by me, made oath that the statements in the
/foregoing document are true.
My Commission expires i'l/y O p .(Signature of Notary Public)_,�L�J�! *c/....
01ARy`,
E� P V3
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