western wake regional

Wastewater Management facilities
engineering report

The Western Wake Wastewater Management Facilities includes wastewater conveyance, wastewater treatment, and effluent conveyance and discharge for three communities (the Towns of Cary, Apex, and Morrisville) and effluent conveyance and discharge for the Town of Holly Springs. These communities are all in the western portions of Wake County, North Carolina, and are collectively called the Western Wake Partners (the Partners).

The Partners are working collaboratively to collect, treat, and discharge wastewater from their communities and Research Triangle Park (RTP) South. As part of this collaborative effort, the Partners are also addressing both a regulatory mandate and recommendation. The regulatory mandate that has been issued by the North Carolina Environmental Management Commission (NCEMC) addresses an Interbasin Transfer (IBT) by the Towns of Apex, Cary, and Morrisville. This mandate requires the towns to return water to the Haw or Cape Fear River Basin after 2010. In addition, the North Carolina Department of Environment and Natural Resources (NCDENR) Division of Water Quality (DWQ) strongly recommended the removal of Holly Springs’ wastewater discharge (National Pollutant Discharge Elimination System (NPDES) permit number NC0063096) from Utley Creek.

This Engineering Report (ER) summarizes the investigation of reasonable action alternatives for the collection, treatment, and discharge of wastewater from the Towns of Cary, Apex, Morrisville, and RTP South, as well as effluent conveyance re-routing for the Town of Holly Springs. The information included in this ER is a summary of information presented in various engineering design reports and environmental studies completed by several engineering consultants engaged in the project. The referenced documents have been attached to this ER as appendices. The Environmental Impact Statement (EIS), prepared by CH2MHill and CDM, is titled Western Wake Regional Wastewater Management Facilities Draft Environmental Impact Statement (DEIS) and is included by reference.

The proposed action alternative, Proposed Project (WRF Site 14), and three reasonable action alternatives; Project Alternate A (WRF Site 19), Project Alternate B (WRF Site 21/23), and Project Alternate C (WRF Site 30) were selected for further analysis as detailed in the Western Wake Regional Wastewater Management Facilities DEIS. These four action alternatives are summarized as Project Alternatives within this ER. All four Project Alternatives are regional wastewater management options that include a regional water reclamation facility (WRF) that would treat wastewater from Apex, Cary, Morrisville, and RTP South. All four Project Alternatives include an outfall line to the Cape Fear River below Buckhorn Dam that would also be sized to accommodate flow from the Holly Springs Utley Creek Waste Water Treatment Plant (WWTP). Each Project Alternative includes a different WRF site with varying piping configurations around each WRF site. The four Project Alternatives all include the same location for the West Cary Pump Station, Beaver Creek Pump Station, and the large portions of the transmission line alignments are the same. A present worth analysis was prepared for each of the four Project Alternatives to demonstrate the cost effectiveness of each alternative. The present worth analysis tables and comparisons are presented in Section 5 of this ER. As summarized below in Table ES.1, the Proposed Project (WRF Site 14) has the lowest present worth cost.

Table ES.1. Present Worth Analysis Summary
Project Facilities	Proposed Project	Project Alternate A	Project Alternate B	Project Alternate C
Project Facilities	(WRF Site 14)*	(WRF Site 19)	(WRF Site 21/23)	(WRF Site 30)
Capital Cost	$329,347,000	$346,727,000	$340,492,000	$334,956,000
Operations and Maintenance Cost	$165,796,000	$168,406,000	$168,799,000	$165,872,000
Replacement Cost	$25,675,000	$27,013,000	$26,500,000	$25,902,000
Salvage Value	($700,000)	($720,000)	($693,000)	($712,000)
Total Estimated Present Worth**	$520,118,000	$541,426,000	$535,098,000	$526,018,000
*Partners Preferred Site.
**Total estimated Present Worth is rounded to nearest $1,000.

Purpose and Need for Action

The purpose of the Western Wake Regional Wastewater Management Facilities Project is to provide the foundation for regional wastewater service capacity to meet existing and forecasted demand in the project service area. The regional wastewater service will be consistent with the NCEMC mandate in the IBT certificate to return water to the Haw or Cape Fear River Basin and the Town of Holly Springs’ commitment to relocate its NPDES discharge from Utley Creek. The need for the proposed action is to provide wastewater treatment capacity for the projected population growth and the associated increase in land development in western Wake County.

The population of the wastewater service area of the Towns of Apex, Cary, Morrisville, and Holly Springs would be approximately 432,250 in 2030. The required maximum monthly wastewater capacity for the towns would be approximately 62 million gallons per day (MGD) – approximately 24 MGD of treated wastewater effluent would be discharged at existing NPDES permitted outfalls, and approximately 38 MGD would be pumped, conveyed, and discharged by the proposed facilities to a new outfall location.

Project Alternatives

An extensive analysis of project alternatives was performed which included an evaluation of Wastewater Management Options, Wastewater Discharge Location Alternatives, WRF Site Alternatives, Pump Station and Alignment Alternatives, and Wastewater Outfall Options. The Western Wake Regional Wastewater Management Facilities DEIS provides details of the process for alternative development and evaluations.

Wastewater Management Options – An evaluation of the following wastewater management options was performed:

§ No Action - the facilities already in place would continue to operate as currently permitted.

§ Independent systems - no collaboration for wastewater collection and treatment and consists of two new WRFs to serve the Western Wake service area.

§ Purchase of capacity from other systems - City of Durham, Durham County or Harnett County would provide treatment capacity.

§ Optimum operation of existing systems - optimum operation of existing plants could result in a rerating of them so they could actually discharge higher flows than permitted.

§ Regional land application system - construction of secondary-type treatment facilities followed by land application to a dedicated land application site.

§ Regional water reuse system - disposal of the entire amount of the reclaimed water through a regional water reuse system.

§ Regional wastewater system – one new WRF to serve Apex, Cary, and Morrisville; Holly Springs continues to operate its WWTP and shares outfall line with other Partners.

From this list, the regional wastewater system alternative was selected. All of the other alternatives were determined to not meet the project purpose and need or would result in much higher environmental impacts than the proposed regional wastewater system, thus eliminated from further detailed study.

Wastewater Discharge Location Alternatives – Various wastewater discharge location alternatives were evaluated which included a discharge to Jordan Lake, to the Cape Fear River upstream of Buckhorn Dam, and to Harris Lake. DWQ had concerns about nutrient enrichment for each of these alternatives as presented to the Project Delivery Team (PDT) at its July 26, 2007 meeting. Both Jordan Lake and the Cape Fear River upstream of Buckhorn Dam are on the state’s 303(d) list because of exceedances of the chlorophyll a standard. Thus, these discharge alternatives were eliminated from further discussion.

Harris Lake is not impaired, but DWQ indicated that it could not permit a new discharge to the lake without detailed water quality modeling. This option is currently being evaluated using a detailed modeling analysis, but to date DWQ has not determined whether a discharge to Harris Lake is feasible (through the issuance of speculative permit limits). The Town of Holly Springs’ preference would be to have a separate discharge to the lake or its watershed since this would reduce the length of effluent pipeline and associated impacts.

DWQ has provided speculative permit limits for a surface water discharge only for a discharge to the Cape Fear River downstream of Buckhorn Dam, and this is currently the proposed discharge location.

WRF Site Alternatives – Thirty WRF site alternatives were evaluated. Seventeen of the candidate sites were eliminated once the wastewater management option and discharge location were identified; they were originally included as a potential WRF location because they were considered appropriate for a different management option. Based upon an independent analysis, the Partners identified Site 14 as the proposed WRF site.

The following criteria to select alternatives to the proposed WRF site (Site 14) were evaluated:

§ Number of dwelling units and unique property owners on the site

§ Site access – distance from a US highway

§ Number of feet of pipeline required for site

§ Ponds, wetlands, and streams on site

§ Significant natural heritage areas, gamelands, public lands, federal land, and state-owned land on site

§ Number of threatened and endangered species within 0.5 mile of site

§ Population within 0.5 mile of site

§ Number of hospitals, churches, daycare centers, schools, and retirement centers within 0.5 mile of site

§ Historic resources within 0.5 mile of site

Based on the above criteria, the following three sites were selected as reasonable alternatives to the proposed WRF site (Site 14) and evaluated further:

§ Site 19 - This site is south of US 1, west of New Hill Holleman Road, and just south of Friendship Road. For this ER, this is known as the Project Alternate A site.

§ Site 21/ 23 - This site is south of US 1, west of New Hill Holleman Road, and just south of Friendship Road. For this ER, this is known as the Project Alternate B site.

§ Site 30 - This site is located north of US 1 and just south of Old US 1 between Shearon Harris and Bonsal Roads. For this ER, this is known as the Project Alternate C site.

If a discharge to Harris Lake is feasible, these same sites score high if Holly Springs would have a separate discharge into the lake or its watershed.

Pump Station and Alignment Alternatives – The location of the West Cary Pump Station is identical for all WRF site alternatives. This pump station currently exists and is being expanded as part of this project. The location of the Beaver Creek Pump Station is also identical for all WRF site alternatives. It was selected based on environmental factors (streams and wetlands), social factors (number of property owners/relocations), and cost. Similarly, the transmission lines for each alternative are similar. The transmission lines were selected to minimize impacts to the environment (wetlands and streams), property owners and residents, the American Tobacco Trail, federal land, and the New Hill Historic District, as well as to minimize conflicts with existing gas lines and power lines.

Wastewater Outfall Options – For the WRF outfall into the Cape Fear River, a bank discharge structure and a diffuser were evaluated. The bank discharge resulted in fewer impacts to recreation and habitat, and resulted in DWQ-acceptable dilution. Thus, the diffuser was eliminated from further detailed analysis, and the bank discharge was selected for all WRF site alternatives.

No Action Alternative

The No Action Alternative assumes that there is no regional wastewater system and that the area to be served by the proposed project would continue to be developed primarily as low density residential development served by on-site water and wastewater systems. The No Action Alternative does not meet the project purpose and need because it does not allow Cary, Apex, and Morrisville to meet the mandate in their IBT certificate and it does not provide the necessary capacity for future wastewater treatment demands.

Summary of Solution

Based on analysis of alternatives summarized above, the proposed action is to build a regional wastewater system that includes the construction of a single WRF to serve the future wastewater Towns of Apex, Cary, and Morrisville and RTP South. The Proposed Project (WRF Site 14) is north of US 1 and just south of Old US 1 between New Hill-Holleman and Shearon Harris Roads. The WRF would be constructed in two phases to a proposed capacity of 30 MGD and is proposed to discharge to the Cape Fear River downstream of Buckhorn Dam. The Town of Holly Springs Utley Creek Wastewater Treatment Plant (WWTP), which has already been approved to expand to 8 MGD, will share the 38 MGD outfall to the Cape Fear River.

The proposed Western Wake Regional Water Reclamation Facilities Project, shown in Figure 1-1, includes the following infrastructure:

§ Western Wake Water Reclamation Facility (Western Wake WRF)

§ Northwest Cary Force Main Diversions

· Cary Green Level Force Main and Gravity Sewer (Cary Western Service Area to
West Cary Pump Station)

· Cary Indian Creek Force Main and Gravity Sewer (Cary Western Service Area to
West Cary Pump Station)

§ Western Wake Influent Conveyance Facilities

· West Cary Pump Station (modification only)

· West Cary Force Main (West Cary Pump Station to West Reedy Branch Gravity Sewer)

· West Reedy Branch Gravity Sewer (West Cary Force Main to Beaver Creek Pump Station)

· Apex Beaver Creek Gravity Sewer (Apex Service Area to Beaver Creek Pump Station)

· Beaver Creek Pump Station

· Beaver Creek Force Main (Beaver Creek Pump Station to WRF)

§ Holly Springs Effluent Facilities Pump Station and Force Main
(Utley Creek WWTP to the Western Wake WRF)

§ Western Wake Effluent Conveyance Facilities

· Western Wake WRF Effluent Pump Station

· Western Wake WRF Effluent Force Main and Outfall (to Cape Fear River)

This proposed solution will provide regional wastewater service capacity to meet existing demand in the project service area, as well as forecasted demand related to projected population growth and the associated increase in land development in western Wake County.

The regional wastewater service proposed will be consistent with the NCEMC mandate in the IBT certificate to return water to the Haw or Cape Fear River Basin and the Town of Holly Springs’ commitment to relocate its NPDES discharge from Utley Creek.

western wake regional

Wastewater Management facilities
engineering report

1. Introduction

1.1 Background

The Towns of Apex, Cary, Holly Springs, and Morrisville (Western Wake Partners) are working collaboratively to collect, treat, and discharge wastewater from their communities and RTP South. The proposed project is to construct and operate a new WRF in western Wake County, North Carolina to provide wastewater treatment capacity to meet regulatory mandates regarding IBT and to provide capacity for the projected population growth in western Wake County. The population of the Partners’ wastewater service areas is projected to increase from approximately 164,800 in 2005 to approximately 220,150 by 2010 and approximately 432,250 by 2030. The project service areas are identified in Figure 1-1.

The Partners will construct and operate the new WRF consistent with the requirements of the Interbasin Transfer Certificate issued to the Towns of Apex, Cary, Morrisville, and Wake County (for RTP South) to return treated wastewater to the Cape Fear River Basin and the Town of Holly Spring’s commitment to relocate its NPDES discharge from Utley Creek.

The Towns of Apex, Cary, Morrisville, and RTP South obtain their drinking water from Jordan Lake in the Cape Fear River Basin and currently discharge treated effluent to locations in the Neuse River Basin. In
July 2001, NCEMC) granted the Towns of Apex, Cary, Morrisville and Wake County (on behalf of RTP South) an IBT certificate to withdraw water from the Cape Fear River Basin and discharge the water to the Neuse River Basin. However, the IBT certificate issued by NCEMC includes a condition requiring the Partners to begin returning a portion of the water withdrawn from Jordan Lake to the Cape Fear River Basin by January 1, 2011. The Town of Cary has an Inter-Local Agreement (ILA) with Durham County for up a maximum daily average of 8 MGD. This includes a maximum monthly average of 4 MGD and a maximum hourly average of 12 MGD. The Town of Cary began meeting its IBT certificate commitment through the ILA on September 1, 2004. The ILA currently expires June 30, 2011.

This project will provide treatment capacity to replace the maximum daily 8 MGD currently provided by Durham County. In addition, the new WRF will provide capacity to treat the remaining wastewater loads which are currently generated in the Cape Fear Basin, but treated and discharged into the Neuse River Basin. The project will also provide treatment for expected growth in western Wake County through 2030.

The Town of Holly Springs has a WWTP that discharges into Utley Creek, a tributary to Harris Lake in the Cape Fear River Basin. Due to nutrient enrichment issues in Utley Creek, NCDENR has urged the Town of Holly Springs to remove its wastewater discharge from Utley Creek and to participate with the Towns of Apex, Cary, and Morrisville in a regional wastewater management program. After considering options, the Town of Holly Springs elected to participate in the planning, permitting, design, and construction of the effluent discharge for the regional wastewater management facilities. As part of Holly Springs’ effort to upgrade and expand the Utley Creek WWTP, the Town made a commitment to NCDENR to relocate the current Utley Creek effluent discharge to the Cape Fear River Basin when the proposed regional wastewater management facilities are operational. NCDENR stated in a Finding of No Significant Impact (FONSI) and Environmental Assessment (EA) dated February 16, 2007 that,

“Any Authorization to Construct or other necessary permits (orders, etc.) for expansion of the Utley Creek WWTP will include a condition stating that the treated effluent must be removed from Utley Creek by the date established in the Certificate authorizing the Towns of Cary, Apex, and Morrisville and Wake County to Increase their Transfer of Water from the Haw River basin to the Neuse River basin under the Provisions of G.S. 143-215.221.”

1.2 Necessary Permits

Several agency permits, approvals, and certifications are required for the construction of the proposed Western Wake Regional Water Wastewater Management Facilities. All applicable permits, approvals, and certifications must be obtained before the project plans and specifications can be approved and the project advertised for bids. There are no major technical or environmental issues concerning the project; therefore preliminary work to obtain the following permits or approvals, where applicable, will begin as soon as possible.

1. Sedimentation and Erosion Control Permit from the Division of Land Quality (DLQ), or a letter from them stating that no permit is required for this project.

Land disturbing activities will be more than one acre, therefore Erosion and Sediment Control (ESC) Permits is will be required. ESC Plans will be submitted to NCDENR DLQ for approval as required.

2. 401 Water Quality Certification and Army Corps of Engineers’ 404 Permit for all stream crossings, or letters from the Army Corps of Engineers and from the Wetlands 401 Certification Unit stating that none is required for this project.

401/404 Permits are anticipated for the following facilities:

· Western Wake Water Reclamation Facility

· Apex Beaver Creek Gravity Sewer

· Western Wake WRF Effluent Pump Station

· Western Wake WRF Effluent Force Main and Outfall (to Cape Fear River)

· West Cary Force Main (West Cary Pump Station to West Reedy Branch Gravity Sewer)

· West Reedy Branch Gravity Sewer (West Cary Force Main to Beaver Creek Pump Station)

· Apex Beaver Creek Gravity Sewer (Apex Service Area to Beaver Creek Pump Station)

· Beaver Creek Pump Station

· Beaver Creek Force Main (Beaver Creek Pump Station to Western Wake WRF)

· Cary Green Level Force Main and Gravity Sewer (Cary Western Service Area to

· West Cary Pump Station)

· Cary Indian Creek Force Main and Gravity Sewer (Cary Western Service Area to

· West Cary Pump Station)

· Holly Springs Effluent Pump Station

· Holly Springs Effluent Force Main

3. Section 10 Permit for aerial crossings of navigable waters, or a letter from the Corps stating that none is required.

No aerial crossings of navigable waters are anticipated for the construction of this project; therefore, a Section 10 Permit from the United States Army Corps of Engineers (USACE) is not required.

4. A reasonable subsurface investigation must be made available to the contractor. If it is not included in the specifications, the specifications must advise where a copy of the report can be observed. Typically, Construction Grants and Loans (CG&L) expects a boring about every 500 feet and at each road crossing for linework, and at all major structures like pump stations, aeration basins, and clarifiers.

Subsurface investigation reports will be prepared for applicable facilities as deemed necessary by the design engineer. These reports will be made available to perspective bidders and the successful
contractor (s). All subsurface investigation reports for this project will meet the minimum CG&L boring requirements, unless otherwise noted in the subsurface investigation reports.

5. Copies of North Carolina Department of Transportation (NCDOT) encroachment agreements and Railroad encroachment agreements. Copies of these agreements must be provided in the specifications, or it must be documented how all construction requirements associated with the agreements have been incorporated into the plan.

It is anticipated that facilities included in this project will encroach into NCDOT and/or Railroad rights-of-way. If determined during final design that proposed facilities will encroach into NCDOT and/or Railroad rights-of-way, then encroachment agreement and/or driveway permit applications will be submitted to the appropriate agencies for approval as required.

6. All construction easements, permanent easements, and rights-of-way must be shown on the plans.

It is anticipated that facilities included in this project will require construction easements, permanent easements, and rights-of-way. If determined during final design that proposed facilities will require easements and/or rights-of-way, the easements and/or rights-of-way will be delineated and submitted to the appropriate agencies for acquisition as required. Conditions of required easements and/or rights-of-way will be reflected on the plans.

7. Easements on private property for construction of STEP systems and grinder pumps. Need to be acquired, and conditions of the easements need to be reflected on the plans.

STEP systems or grinder pumps are not part of this project; therefore, the acquisition of easements for these systems is not required.

8. NPDES Permit when the project involves a new discharging facility or expansion to an existing one.

A NPDES permit will be required for the Western Wake Water Reclamation Facility and a new or modified permit will be required for the Holly Springs Utley Creek WWTP.

1.3 Other Information

Western Wake Partners understands that approval of the ER does not constitute approval of sole source procurement. Plans and specifications will comply with NC General Statutes Chapter 133, Section 4. In addition, Western Wake Partners understands that receipt of loans is contingent upon the review and approval of the proposed loan by the Local Government Commission.

Engineering designs for the Western Wake Regional Wastewater Management Facilities will conform to the minimum design criteria for both non-discharging and discharging facilities found in the new 15A NCAC 2T Rules.

A copy of the executed ILA (with amendments) between the Towns of Apex, Cary, Holy Springs and Morrisville for the Western Wake Wastewater Management Facilities is included in Appendix A.

Currently, SRF loan participation in Laboratory/Administrative buildings funding is limited to $170 per square foot. The participation amount is revised annually, based on construction cost indices. SRF loans will not cover the total cost of the Western Wake Regional Water Reclamation Facilities. The SRF loan of $70 million is approximately 22 percent of the total estimated capital project cost of $329,347,000. SRF loans will not need to be used for Laboratory/Administrative buildings; therefore, total square footage of these buildings does not need to be listed separately in the bid form. SRF loans will be applied toward site work and the liquid treatment train facilities within the project.

western wake regional
Wastewater Management facilities

engineering report

2. Current Situation

2.1 Existing Treatment System

The Towns of Apex and Holly Springs currently maintain separate wastewater treatment facilities. The Town of Cary assumed ownership and management of the Town of Morrisville’s Wastewater System in April 2006. The existing wastewater treatment systems for each Western Wake Partner is further described in this section. It should be noted that the population and demographics, and wastewater flows discussed are specific to the existing treatment facilities within the existing service areas.

2.1.1 Town of Cary

The Town of Cary’s wastewater collection system is separated into three systems: the north, south, and west systems and includes over 716 miles of pipelines and 37 pump stations as of January 2009. The Town of Cary service areas are identified in Figure 2-1. The Town of Cary currently operates two wastewater treatment facilities: the North Cary WRF and the South Cary WRF. The Walnut Creek Pump Station, which is capable of pumping wastewater to either the North Cary or South Cary WRF, is currently configured to pump to the South Cary WRF.

The North Cary WRF has a design flow of 12 MGD and serves northern Cary, portions of the Town of Morrisville and the Raleigh-Durham International Airport. The North Cary WRF discharges into Crabtree Creek in the Neuse River Basin. The North Cary WRF was originally completed in 1983. The North Cary WRF was expanded to 10 MGD in 2003 and 12 MGD in 2005.

The South Cary WRF serves the southern portion of Cary and has a design flow rate of 12.8 MGD. The South Cary WRF is permitted to release up to 16 MGD to Middle Creek in the Neuse River Basin. The original South Cary WRF was brought online on January 2, 1989.

The West Cary service area collects wastewater generated within its boundaries and receives flows from five peripheral service areas: RTP South, Upper Crabtree Pump Station service area, residual flows from the Cary/Apex Water Treatment Plant, and selected portions of Morrisville and Apex. There are three primary pump stations within the western service area: West Cary, Morris Branch, and Kit Creek.

Currently, the West Cary Pump Station, constructed in 2007, pumps wastewater to the Morris Branch Pump Station, which then pumps wastewater flow to the Kit Creek Pump Station. The Kit Creek Pump Station sends flow from all five peripheral areas to the Durham County Triangle WWTP. The Town of Cary may transfer a maximum daily average of 8 MGD (maximum monthly average of 4 MGD and maximum hourly average of 12 MGD) to the Durham County Triangle WWTP under agreement with Durham County. The agreement expires on June 30, 2011.

According to the 2007-2008 Town of Cary Annual Wastewater Report, the Town of Cary had fourteen Sanitary Sewer Overflows (SSOs) from July 1, 2007 to June 30, 2008, which discharged a total of 12,035 gallons of raw sewage. There is no Special Order of Consent (SOC) that applies to the Town of Cary WRFs.

2.1.2 Town of Apex

Wastewater from the Town of Apex is treated at the Middle Creek WWTP. The WWTP has a design flow of 3.6 MGD and discharges into Middle Creek, part of the Neuse River Basin. The original Middle Creek WWTP was completed in 1988. The Town of Apex owns, operates, and maintains over 140 miles of gravity sewer, 33 miles of force mains, and 19 pumping stations. The Town of Apex also has an agreement with the City of Raleigh for the option to send an average daily flow rate of 1 MGD (not to exceed 1,800 gallons per minute (GPM)) of raw wastewater to the Neuse River WWTP, owned and operated by the City of Raleigh. The Town of Apex service area is identified in Figure 2-2. As shown in Figure 2-2, the Middle Creek WWTP service area does not include all parts of the Town of Apex.

According to the 2007-2008 Town of Apex Annual Wastewater Report, the Town of Apex experienced two SSOs from July 1, 2007 to June 30, 2008, which discharged a total of 18,840 gallons of raw sewage. There is no SOC that applies to the Town of Apex Middle Creek WWTP.

2.1.3 Town of Holly Springs

The Town of Holly Springs owns and operates the Utley Creek WWTP, a facility with a current capacity of 1.5 MGD and a NPDES permitted capacity of up to 2.4 MGD that discharges into Utley Creek, a tributary to Harris Lake and the Cape Fear River. The original Utley Creek WWTP was completed in 1985; with secondary and tertiary treatment facilities added in January 1996 and 2000, respectively. The Utley Creek WWTP is currently under construction to expand to 6 MGD. This system includes approximately 21 miles of collection system gravity and force main sewers and 18 pump stations. The Town of Holly Springs service area is identified in Figure 2-3.

According to the 2007-2008 Town of Holly Springs Utley Creek Wastewater Treatment Plant Annual Wastewater Performance Report, the Town of Holly Springs reported one SSO from July 1, 2007 to June 30, 2008, which discharged a total of 5,000 gallons of raw sewage due to debris blocking the line. There is no SOC that applies to the Town of Holly Springs Utley Creek WWTP.

2.1.4 Town of Morrisville

The Town of Cary assumed ownership and management of the Town of Morrisville’s water and sanitary sewer system in April 2006. As of January 2009, the wastewater collection system encompasses approximately 74 miles of interceptors and force mains and 11 pump stations, and is serviced by the Town of Cary’s northern and western service areas. Wastewater from the northern portion of Morrisville is conveyed to and treated by the Town of Cary’s North Cary WRF. The portion of wastewater collected from the Town of Morrisville within the Town of Cary’s western service area is pumped by the Kit Creek Pump Station to the Durham County Triangle WWTP. The Town of Morrisville and the North Cary WRF are identified in Figure 2-1.

2.1.5 Report Reference

More detailed information on the Partner’s existing treatment systems may be found in Section 3 of the Western Wake County Regional Wastewater Treatment Studies Project Phase I Report prepared by CDM and Hazen and Sawyer, dated February 2004 (Appendix B).

§ Town of Apex – Section 3.1

§ Town of Cary – Section 3.2

§ Town of Holly Springs – Section 3.4

§ Town of Morrisville – Section 3.5

Additional information about the Town of Cary western service area may be found in Section 2 of the Preliminary Engineering Report for the West Cary Pump Station and Force Main dated December 2004 by Brown and Caldwell (Appendix C).

2.2 Population and Demographics

The population of the existing wastewater service area of the Towns of Apex, Cary, Morrisville, and Holly Springs was approximately 164,800 in 2005. Table 2.1 presents the overall populations in 2000 and 2007 for the Towns of Apex, Cary, Holly Springs, and Morrisville, as well as the existing wastewater service area population in 2005.

Table 2.1. Town Populations
Partner	2000 Census Data	2005 Service Area Population	2007 Certified Population Estimate (NC Office of State Budget and Management)
Apex	20,212	28,330	29,973
Cary	95,949	113,460	132,443
Holly Springs	9,192	15,090	19,474
Morrisville	5,208	7,920	14,308
Total	130,561	164,800	196,198

Additional information pertaining to service area population may be found in Appendices B.4 and C.1 of the Western Wake Regional Wastewater Management Facilities DEIS.

2.3 Infiltration/Inflow

Infiltration/Inflow (I/I) is extraneous water that enters the wastewater collection system from groundwater and surface water. I/I occurs at a relatively low rate throughout the year and typically increases significantly during rainfall events. The Western Wake WRF will primarily serve future service areas where wastewater collection systems have not yet been constructed. Upon completion of the Western Wake WRF, the Kit Creek Pump Station and the Morris Branch Regional Pump Station will convey wastewater from the northwestern portions of the Town of Cary (currently routed to the Durham County Triangle WWTP) to the West Cary Pump Station. The West Cary Pump Station will pump the re-routed wastewater southward to the Beaver Creek Pump Station and subsequently to the Western Wake WRF. The Town of Cary’s I/I remediation program will be applied to minimize I/I sources within the re-routed northwestern Cary service area.

Additional information on I/I for the Town of Cary, Morrisville, RDU, and RTP South may be found in Section 4 of the Town of Cary Wastewater Collection System Master Plan, dated June 2003 by Hazen and Sawyer (Appendix D) and in Appendix C.1 of the Western Wake Regional Wastewater Management Facilities DEIS.

2.3.1 Town of Cary

The Town of Cary has an aggressive I/I remediation program. Hazen and Sawyer evaluated groundwater infiltration and rainfall dependent I/I for the Town of Cary and documented the evaluation in a report entitled Town of Cary Wastewater Collection System Master Plan dated June 2003 (Appendix D). A summary of estimated I/I quantities based on billed water demand multiplied by the estimated fraction of the billed water demand that is returned to the wastewater collection system is presented in Table 2-5 of the Town of Cary Wastewater Collection System Master Plan. I/I ranged from 5.9 to 15.5 percent of the total North and South Cary WRF flows for the years 1995 through 1998. The I/I for the four years averaged approximately 12.1 percent of the total North and South Cary WRF flows. Accordingly, an I/I value of 10 percent was used for flow projections in the Town of Cary Wastewater Collection System Master Plan to reflect future reductions in I/I due to I/I rehabilitation.

Summary results for detailed I/I calculations based on a flow monitoring program conducted by Hazen and Sawyer are presented in Section 4 of the Town of Cary Wastewater Collection System Master Plan.

The Town of Cary’s fiscal year 2008 utility capital improvements plan for sanitary sewer includes approximately $3.6 million for force main inspections and rehabilitation, approximately $739,000 for replacement and rehabilitation of existing sanitary sewer, and approximately $580,000 for replacement and rehabilitation of existing sanitary sewer for the Town of Morrisville merger.

2.3.2 Town of Apex

The Town of Apex budgets for I/I remediation annually. Expenditures for fiscal year 2007-2008 were $300,000. There is $350,000 budgeted for I/I remediation for fiscal year 2008-2009.

2.3.3 Town of Holly Springs

I/I calculations were conducted for the Town of Holly Springs Utley Creek WWTP expansion in 2004. Infiltration was calculated at 418 gallons per day (GPD)/inch-mile of sewer and 70 GPD/capita, well below the excessive I/I thresholds set forth by SRF programs. Additional information for the Town of Holly Springs may be found in the Section 3.4 of the Town of Holly Springs Utley Creek Wastewater Treatment Plant 201 Facility Plan Amendment prepared in August 2006 by Davis Martin Powell and Green Engineering (Appendix E). The Town of Holly Springs has set aside funds from their Engineering Enterprise Fund for Inflow and Manhole Rehabilitation projects. Funds are estimated at $430,000 total for fiscal years 2008 and 2009.

2.3.4 Town of Morrisville

The Town of Cary assumed ownership and management of the Town of Morrisville’s water and sanitary sewer system in April 2006. The Town of Cary’s I/I remediation program noted in Section 2.3.1 encompasses the wastewater collection system located within the town limits of Morrisville.

2.4 Wastewater Flows

The Western Wake WRF will serve the Towns of Cary, Apex, Morrisville, as well as RDU and RTP South. The Town of Holly Springs is a participant in the effluent and discharge facilities as they are continuing to treat their wastewater at the Utley Creek WWTP. The Western Wake WRF will serve the Towns of Cary, Apex, Morrisville, as well as RDU and RTP South. The Town of Holly Springs is a participant in the effluent and discharge facilities as they are continuing to treat their wastewater at the Utley Creek WWTP. In 2001, these areas produced a maximum monthly wastewater flow of 17.6 MGD.

Table 2.2 shows the maximum monthly wastewater flows of each Partner in the year 2001 as presented in Table 2.3 of the Western Wake County Regional Wastewater Treatment Studies Project Phase I Report (Appendix B).

Table 2.2. Wastewater Flows
Partner	2001 Maximum Monthly Wastewater Flows (MGD)	2007-2008 Annual Average Wastewater Flows (MGD)²
Apex	2.40	2.19
Cary	12.79¹	10.64
Holly Springs	0.82	0.969
Morrisville	0.99	Included in Cary Flows
RDU and RTP South	0.62	Included in Cary Flows
1Cary flows are from the June 2003 Wastewater System Master Plan by Hazen and Sawyer ²Flows are from the FY07-08 Annual Sewer Reports for each Town

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3. Future Situation

3.1 Population and Demographics

The population of the wastewater service area of the Towns of Apex, Cary, Morrisville, and Holly Springs is estimated to increase to approximately 220,150 in 2010 and approximately 432,250 in 2030. These population projections are land-use based. Long-term population projection forecasts remain unchanged despite the current economic situation in late 2008 and early 2009. The approach used to estimate the Western Wake WRF service area for each Partner is further described below.

Town of Apex –The Town of Apex has experienced a very high rate of growth in the past decade. According to the U.S. Census, the Town’s population increased over 300 percent from 1990 to 2000. Apex’s growth is part of the growth of the entire Research Triangle Park area, which has experienced steady growth since the mid 1960s. The communities closest to Research Triangle Park in western Wake County have been particularly influenced by this growth, and these communities are expected to continue to grow. Population projections for the Town of Apex are based on the assumption that 50 percent of the unresolved area between Apex and Holly Springs will be served by each town.

Towns of Cary and Morrisville –Population projections for the Town of Cary service area were developed in the Town of Cary Wastewater Collection System Master Plan, dated June 2003 by Hazen and Sawyer (Appendix D). The Cary wastewater service area includes the service area for the Town of Cary customers within the Town limits. In addition to its citizens and individual customers, the Town of Cary also provides wastewater treatment for the Town of Morrisville, RDU International Airport, and RTP South.

Population projections for the Town of Cary were based on population data provided by the Capital Area Metropolitan Planning Organization (CAMPO), and by the Durham/Chapel Hill/Carrboro Metropolitan Planning Organization (D/CH/C/MPO). The population projections were divided into Traffic Analysis Zones (TAZs), for which data were available for various parameters, including population and employment for 1995 through 2025. These data were based on the Town’s 1996 Land Use Plan.

Adjustments to the population projections from the TAZ data were made for areas in the western and extreme southern portions of the Cary service area, for which more recent plans exist (since 1996). These plans include Planned Unit Developments (PUDs) and activity centers. Population projections for ultimate buildout of the PUDs were based on dwelling unit projections provided by the Town of Cary and an estimated 2.5 persons per dwelling unit.

Fifteen activity centers (ACs) are projected for the Cary service area, including 12 in the western service area and three in the southern service area. An activity center is a cluster of businesses and establishments, with an associated increased level of surrounding residential development. Three types of activity centers were projected: Regional Activity Centers (RACs), Community Activity Centers (CACs) and Neighborhood Activity Centers (NACs). Potential AC locations and flows for the three types of ACs were provided by the Town of Cary.

Projected wastewater service area populations for the Town of Cary were based on the overlay of the service area boundaries on the TAZ data, plus the above adjustments to the TAZ data. The projected service area population for 2030 was developed based on the 2025 population data. Population projections for the other planning years, i.e., 2005, 2010, 2015, 2020, and 2025, were determined by interpolation.

Population projections for the Town of Morrisville were not included in the Town of Cary Wastewater Collection System Master Plan, dated June 2003 by Hazen and Sawyer (Appendix D). However, population projections for the Town of Morrisville were presented in the Round III Jordan Lake Water Supply Storage Allocation Application submitted by CH2MHill and CDM in May 2001. These projections were used for projecting the 2030 Morrisville population; population projections for earlier years were adjusted to reflect current growth estimates.

Town of Holly Springs – Population projections for the Town of Holly Springs were developed for and are documented in the Town of Holly Springs Utley Creek WWTP 201 Facility Plan Amendment dated August 2006 by Davis Martin Powell and Green Engineering (Appendix E). As noted for the Town of Apex population projections, the population projections for the Town of Holly Springs are also based on the assumption that 50 percent of the unresolved area between Apex and Holly Springs will be served by each town.

3.2 Wastewater Flows

The Western Wake WRF will serve the Towns of Cary, Apex, Morrisville, as well as RDU and RTP South. Wastewater flow projections for the various service areas within these towns that will be served by the Western Wake WRF are presented in Table 3.1 below and in Table 1-2 of the Western Wake Regional Wastewater Management Facilities DEIS.

Table 3.1. Western Wake WRF Flow Projections Maximum Monthly Flows (MGD)
	2011	2015	2020	2025	2030
Western Cary Service Area	4.36	5.95	7.93	9.04	10.15
North Cary WRF Flow Diversions	-	-	-	-	-
Cary	-	-	-	0.36	1.03
Morrisville	-	-	0.18	0.63	0.76
North Cary WRF Flow Diversion Total	-	-	0.18	0.99	1.79
Morrisville – Haw	1.03	1.28	1.41	1.53	1.66
RTP South	1.42	1.81	2.29	2.78	3.27
Western Apex Service Area	3.12	3.71	5.35	7.44	8.66
Apex Middle Creek Flow Diversions	-	-	0.60	0.60	0.60
Cary/Apex WTP Residuals	-	-	0.40	1.40	2.40
Total WRF	9.92	12.75	18.16	23.77	28.53
Holly Springs Utley Creek WWTP	3.96	4.86	6.00	7.14	8.28
Total Discharge to Cape Fear River	13.88	17.61	24.16	30.91	36.81

Town of Apex – Wastewater flow projections were developed separately for the Town of Apex service areas in the Neuse River and Cape Fear River Basins. The portion of the Apex service area in the Neuse River Basin will predominantly be served by the existing Apex Middle Creek WWTP, while the portion of the Apex service area in the Cape Fear River Basin will predominantly be served by the Western Wake WRF. A gallon per day per capita flow (gpcd) of 48.6 was calculated based on historical wastewater flows and population data for 2002-03. This value was increased to 64.5 gpcd for future flows to more closely reflect typical per capita flows. Based on a comparison of maximum month average daily flows (MMFs) to annual average daily flows (ADFs) for 2002 and 2003, a peaking factor of 1.23 is used for projecting MMFs. Currently, all of Apex’s flow is treated at the Middle Creek WWTP.

Town of Cary – Wastewater flow projections for the Town of Cary wastewater service area were developed based on flows presented in the Town of Cary Wastewater Collection System Master Plan. These projections were developed for residential, commercial, industrial and institutional categories and are presented as follows. Residential wastewater flows were projected based on the projected service area population and a projected residential per capita wastewater flow rate of 70 gpcd. This per capita flow rate was based on the 1998 residential per capita water consumption rate, including irrigation, of 76.8 gpcd times a water return rate to the wastewater collection system of 90 percent.

Commercial wastewater flow projections were developed using employment projections and a unit wastewater flow rate of 65 gpd/employee based on 1998 data. Employment projections were based on the employment (TAZ) data provided by the CAMPO and the D/CH/C/MPO. Adjustments to employment data provided by CAMPO were made for PUDs and ACs in the western and extreme southern portions of the Cary service area. For the PUDs and ACs, commercial and office flows were generally based on a flow rate of 0.09 to 0.12 gpd/sq. ft.

Industrial wastewater flow projections were developed using employment projections by TAZ areas by CAMPO and D/CH/C/MPO in a similar manner as for the commercial wastewater flow projections, and a unit wastewater flow rate of 12 gpd/employee, which was estimated based on 1988 data. Industrial employees from the CAMPO data for PUD and AC areas were subtracted from total industrial employees because no industrial flows are projected for PUDs and ACs. Institutional wastewater flow was projected to be approximately 2.5 percent of residential wastewater flow based on historical water demand data. Institutional flows for ACs were provided by the Town of Cary.

Wastewater flow projections for RDU International Airport were provided by the Town of Cary, and were developed based on wastewater billing data from June 1998 through July 2004 and projected increases over the planning period.

RTP is owned by the private, not-for-profit Research Triangle Foundation (RTF). Water and sewer service for RTP South is provided by the Town of Cary in accordance with a three-party interlocal agreement involving RTF, the Town of Cary and Wake County. Wastewater flow forecasts for RTP South were developed by the Town of Cary in consultation with representatives from RTF.

Town of Morrisville – The Town of Cary assumed ownership and management of the Town of Morrisville’s water and sanitary sewer system in April 2006. Future flows for the Town of Morrisville are incorporated into Town of Cary’s wastewater flows projections.

Town of Holly Springs – Wastewater flow projections for the Town of Holly Springs were developed based on water and sewer billing records, daily monitoring report (DMR), data, and future land use plans.

The following inputs were used in the flow projections:

1. Residential flow of 70 gpcd; (2) commercial flow of 15 gpcd

2. Industrial allowance of 10 percent residential and commercial flow

3. Committed industrial flow of 0.125 MGD; and (5) and allowance for infiltration and inflow equal to
0.32 MGD.

Additional information may be found in Section 4.1.1 of the Town of Holly Springs Utley Creek WWTP 201 Facility Plan Amendment dated August 2006 by Davis Martin Powell and Green Engineering (Appendix E).

3.3 Reclaimed Water Flows

As stated in the Western Wake County Regional Wastewater Treatment Studies Project Phase I Report prepared by CDM and Hazen and Sawyer and dated February 2004 (Appendix B), reclaimed water account data from the Town of Cary’s reclaimed water billing system, as well as parcel data and reuse plans from each local government were used to estimate reclaimed water demands for mixed-use development projects. By the year 2030, it is anticipated that Apex, Cary, Holly Springs, Morrisville, and RTP South will have a reclaimed water demand of approximately 7.61 MGD. These values were calculated based upon a uniform usage rate of 211 gallons per acre per day as an annual average reclaimed water demand for the entire service area. Where more specific data regarding future land use was available, a more site-specific analysis was performed. Reclaimed water demand was primarily assigned to areas where new development of relatively high density (residential, commercial, or mixed use) is expected to occur.

There are presently no plans to retrofit already-developed areas with reclaimed water lines, except for a few minor exceptions such as schools or parks that have an existing agreement with the respective Town for such service. Reclaimed water is used to directly replace potable water for uses such as irrigation and cooling, and thus does not alter the capacity demand of the Western Wake WRF. Table 3.2 presents the reclaimed water demands organized by Partner and River Basin as presented in Table 2.5 of the Western Wake County Regional Wastewater Treatment Studies Project Phase I Report prepared by CDM and Hazen and Sawyer and dated February 2004 (Appendix B).

Table 3.2. Projected Future Reclaimed Water Demands in 2030, by Partner and Drainage Basin
Reclaimed Water Demand by Basin (MGD)
Partner	Haw River Basin	Cape Fear River Basin	Neuse River Basin	Total
Apex	0.53	1.19	0.31	2.03
Cary	1.79	0.00	1.50	3.29
Holly Springs	0.00	1.91	0.02	1.93
Morrisville	0.00	0.00	0.20	0.20
RTP South	0.16	0.00	0.00	0.16
Total	2.48	3.10	2.03	7.61

3.4 Speculative Limits

Speculative effluent limits were issued by the NCDENR, DWQ, Point Source Branch, for the Western Wake Water Reclamation Facility discharge into the Cape Fear River below Buckhorn Dam (Appendix F). These effluent limits are presented in Table 3.3 as monthly and weekly averages, daily minimums, or seasonal averages, depending on the effluent parameters. Speculative effluent limits were also issued by the NCDENR DWQ for the expansion of the Holly Springs Utley Creek WWTP and are presented in Table 3.4.

Additional information regarding the speculative limits for the Western Wake WRF and the Holly Springs Utley Creek WWTP expansion can be found in Appendix A.7 of the Western Wake Regional Wastewater Management Facilities DEIS.

Table 3.3. Speculative Effluent Limits for the Western Wake Regional Wastewater Management Facilities
Effluent Parameter	Monthly Average	Weekly Average	Daily Maximum	Seasonal Average (April - October)
Flow	30 MGD	-	-	-
BOD (Summer)	5.0 mg/L	7.5 mg/L	-	-
BOD (Winter)	10.0 mg/L	15.0 mg/L	-	-
TSS	30.0 mg/L	45.0 mg/L	-	-
NH₃ as N (Summer)	1.0 mg/L	3.0 mg/L	-	-
NH₃ as N (Winter)	2.0 mg/L	6.0 mg/L	-	-
Dissolved Oxygen¹	-	-	6.0 mg/L	-
TRC⁴	-	-	28 ug/L	-
Fecal Coliform (Geometric Mean)	200/100 ml	400/100 ml	-	-
Total Phosphorus²	-	-	-	500 lb/day
Total Nitrogen³	-	-	-	1501 lb/day
1Compliance for Dissolved Oxygen will be measured at the WRF compliance point and evaluated as a daily average concentration. 2Limit based on 2 mg/L Total Phosphorus. For lower flow limits, limit would be based on 2 mg/L and the lower permitted flow. 3Limit based on 6 mg/L Total Nitrogen. For lower flow limits, limit would be based on 6 mg/L and the lower permitted flow. 4Limit to be applied only if chlorine is used for disinfection.

Table 3.4. Speculative Effluent Limits for the Holly Springs Utley Creek Water Reclamation Facility
Effluent Parameter	Monthly Average	Weekly Average	Daily Maximum	Seasonal Average (April - October)
Flow	8 MGD	-	-	-
BOD (Summer)	5.0 mg/L	7.5 mg/L	-	-
BOD (Winter)	10.0 mg/L	15.0 mg/L	-	-
TSS	30.0 mg/L	45.0 mg/L	-	-
NH₃ as N (Summer)	1.0 mg/L	3.0 mg/L	-	-
NH₃ as N (Winter)	2.0 mg/L	6.0 mg/L	-	-
Dissolved Oxygen¹	-	-	6.0 mg/L	-
TRC⁴	-	-	28 ug/L	-
Fecal Coliform (Geometric Mean)	200/100 ml	400/100 ml	-	-
Total Phosphorus²	-	-	-	133 lb/day
Total Nitrogen³	-	-	-	400 lb/day
1Compliance for Dissolved Oxygen will be measured at the WRF compliance point and evaluated as a daily average concentration. 2Limit based on 2 mg/L Total Phosphorus. For lower flow limits, limit would be based on 2 mg/L and the lower permitted flow. 3Limit based on 6 mg/L Total Nitrogen. For lower flow limits, limit would be based on 6 mg/L and the lower permitted flow. 4Limit to be applied only if chlorine is used for disinfection.

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4. Alternatives Analysis

4.1 Alternatives Analysis

Wastewater Management Options, Wastewater Discharge Location Alternatives, WRF Site Alternatives, Pump Station and Alignment Alternatives and Wastewater Outfall Options were evaluated in detail. Each step of the process is discussed briefly in this section, summarizing all options/alternatives chosen and those that were dismissed. Refer to Section 2 of the Western Wake Regional Wastewater Management Facilities DEIS prepared by CH2MHill and CDM for more information.

4.1.1 Wastewater Management Options

To serve the wastewater needs in Western Wake County, seven Wastewater Management Options were evaluated. These options alternatives are presented in more detail in Section 2.3 and Appendix B.5 of the Western Wake Regional Wastewater Management Facilities DEIS.

Management Option 1 – No Action – Option 1 is the No Action alternative, in which the Towns of Cary, Apex, and Holly Springs would continue to operate their existing facilities, without any additional infrastructure. The No Action alternative was deemed infeasible because it would not meet the NCDWQ’s requirement to remove Holly Springs’ current wastewater discharge from Utley Creek (into Harris Lake) or the requirements of the IBT certificate to return water to the Cape Fear River by 2011. Nor would this alternative meet the treatment capacity demands of the service area that will occur over the next 20-year planning period.

Management Option 2 – Regional System (Referenced in DEIS as Proposed Action) – Option 2 is a regional system, in which the Partners evaluated four different regional wastewater management solutions (A, B, C, and D). Each of these potential solutions involved various combinations of cooperation by Cary, Apex, Morrisville, Holly Springs, and Wake County as briefly described below.

§ Solution A: Apex-Holly Springs Collaboration, New West Cary WRF - A new 16 MGD WRF would be constructed to discharge into Jordan Lake and would serve west Cary, the Haw River portions of Morrisville and Apex, and RTP South. Apex and Holly Springs would collaborate to construct a new
20 MGD WRF on Little White Oak Creek and serve the remainder of the Apex service area and any excess flow from Holly Springs that exceeds the capacity of the Utley Creek WWTP. This WRF would have an effluent force main that would tie into the new WRF at Jordan Lake.

§ Solution B: Apex-Cary-Holly Springs Collaboration - Apex and Cary would collaborate to construct one new 18 MGD WRF at Beaver Creek to serve western Cary, part of the Apex service area, the Haw River portion of Morrisville, and RTP South and discharge to the lower portion of Jordan Lake. Apex would also collaborate with Holly Springs to construct a second new 20 MGD WRF at White Oak Creek to serve the remainder of the Apex service area and all of Holly Springs and discharge into the Cape Fear River below Buckhorn Dam. This option would call for the Utley Creek WWTP to be decommissioned.

§ Solution C: Apex-Cary-Holly Springs Collaboration, Excess Holly Springs Flow to North Hartnett Regional WWTP - A new 24 MGD WRF would be constructed at White Oak Creek to serve part of the Apex service area, the Haw River portion of Morrisville, western Cary, and RTP South and discharge to the lower portion of Jordan Lake. Additionally, Holly Springs would collaborate with Harnett County to expand the North Hartnett Regional WWTP by about 7 MGD, and would then utilize this expansion for any flows that exceed the capacity of the Utley Creek WWTP and for flows from the Cape Fear River portion of the Fuquay-Varina service area. The North Cary WRF would be expanded to 16 MGD to serve North Cary, the Neuse River portion of Morrisville, and RDU, and the South Cary WRF would be expanded to 15 MGD to serve South Cary and the Neuse River portion of the Holly Springs service area.

§ Solution D: Apex-Cary-Holly Springs Collaboration, Expansion of Holly Springs’ Utley Creek WWTP - DWQ made the decision to not permit a discharge to Jordan Lake, and that discharges must be made to the Cape Fear River, downstream of Buckhorn dam. Thus, the Town of Holly Springs would continue to operate the expanded Utley Creek WWTP, and then convey the treated effluent to the Western Wake WRF outfall. The Town of Cary would convey raw wastewater from North Cary to the Western Wake WRF.

These solutions, with the exception of Solution D – Apex – Cary –Holly Springs Collaboration, Expansion of Holly Springs’ Utley Creek WWTP were eliminated from further detailed study because they would generate greater WRF site impacts, longer conveyance lines, more stream crossings, wetland impacts, and higher cost than the proposed project. Solution D – Apex –Cary –Holly Springs Collaboration was justified based on the cost, impacts, and at NCDWQ’s request, a regional approach to meet future wastewater capacity needs.

Management Option 3 – Independent Systems – The independent system alternative involves no collaboration for wastewater collection and treatment and the construction of two new WRF’s to serve the western Wake area. This alternative has the highest cost and would result in longer conveyance lines and the most environmental impacts on streams and wetlands. It also does not meet the DWQ request that western Wake communities develop a regional approach to meet future wastewater capacity needs.

Management Option 4 – Purchase Capacity – Option 4 evaluated the purchase of capacity from Durham County, the City of Durham, and Harnett County. None of these facilities have the capacity to handle the projected wastewater treatment needs of western Wake County. This alternative would be costly and would cause the facilities to exceed the nutrient loading total maximum daily load (TMDL) limits of the receiving water.

Management Option 5 – Optimum Operation of Existing Facilities – Optimum operation of the existing facilities was investigated. The wastewater treatment facilities operated by the Towns of Apex and Cary discharge into the Neuse River. Continuing to use these facilities would not meet future demands for wastewater treatment capacity, nor would it satisfy the IBT certificate requirement to return treated effluent to the Cape Fear River by 2011. The Town of Holly Springs’ wastewater treatment facility currently discharges into Utley Creek. NCDWQ is requiring that the Town remove its discharge from Utley Creek as a condition of its discharge permit. Thus, operating the existing facilities at optimum levels would not meet IBT or NCDWQ requirements and would not meet the increasing wastewater treatment capacity demands.

Management Option 6 – Land Application – Land application would require 6,300 acres of land to treat the Phase 1 (2020) 18 MGD capacity at a rate of approximately ¾ inches per week through a spray irrigation system. This land would need to be cultivated with a cover crop, and additional 700 acres of land would be required for buffers around the site, for facilities for the treatment of raw wastewater, and for operation and maintenance buildings. Approximately 11,700 acres would be required to meet the 30 MGD (to year 2030) capacity needs. Due to the close proximity of many water bodies in Western Wake County, the land area would have to be located in Chatham or Harnett Counties, which would require working with additional local governments and obtaining more permits. Furthermore, the cost of land and operations would make this alternative the most expensive option.

Management Option 7 – Regional Water Reuse System – A Regional Water Reuse System, to meet service area wastewater demands, is not feasible in this area. The demand for reclaimed water is high during the hot, dry summer season but has little to no demand during the cool, wet winter season. This alternative would still require a 38 MGD wastewater treatment facility to accommodate the 2030 demands. Nonetheless, the Partners will continue to advocate the use of reclaimed water, and will work to maintain and expand their existing programs to provide reclaimed water to residents, businesses, and industries located in close proximity to the facility.

4.1.2 Discharge Location Alternatives

The Partners evaluated three alternative discharge locations to discharge wastewater. Alternative discharge locations include: New Hope Arm of Jordan Lake, Cape Fear River/Haw River above Buckhorn Dam, and Cape Fear River below Buckhorn dam.

Cape Fear River below Buckhorn Dam (Referenced in DEIS as Proposed Action) – NCDWQ representatives indicated that their preferred discharge location is to the Cape Fear River below Buckhorn Dam. The Cape Fear River below Buckhorn Dam was preferred because water quality modeling suggested that this segment of the Cape Fear River can accommodate additional wastewater effluent loadings without creating unacceptable water quality conditions.

The recommended discharge location best addressed concerns for both water quality issues and nutrient enrichment to an impaired water body. Alternatives considered but eliminated because of these criteria include:

New Hope Arm of Jordan Lake (above Jordan Lake Dam and below US 64) – The upper New Hope Creek arm of Jordan Lake was placed on the 2002 303(d) list for nutrients based on exceedance of the chlorophyll a standard. NCDWQ updated a water quality model for the lake upon which to base a TMDL for nutrients. The Partners applied this model to determine the impact of a proposed discharge on chlorophyll a in the lake. The results indicated that there was little difference in the frequency of predicted chlorophyll a standard violations.

Cape Fear River/Haw River above Buckhorn Dam – In earlier studies, some of the Partners evaluated the potential to discharge to either the Haw or Cape Fear Rivers upstream of Buckhorn Dam. NCDWQ advised them that they should pursue a discharge downstream of Buckhorn Dam based on observed chlorophyll a exceedances and unusual variation in dissolved oxygen levels behind Buckhorn Dam (NCDWQ, 2005). NCDWQ continues to maintain this position. Based on the water quality issues in the Cape Fear River upstream of Buckhorn Dam, this alternative was eliminated from further detailed study in the Western Wake Regional Wastewater Management Facilities DEIS.

Harris Lake/Utley Creek –The Partners evaluations of a discharge to Harris Lake are ongoing. This option results in a shorter effluent line, less pumping, and fewer greenhouse gas emissions from the pumping. It also provides greater flexibility in managing water resources on a regional basis as the water would be stored in the lake. However, NCDWQ has concerns that a new discharge to Harris Lake could result in violations of the chlorophyll a water quality standard of 40 μg/L. The agency has stated that it cannot permit a discharge to Harris Lake without a calibrated nutrient response model.

These alternatives were reviewed by NCDWQ. NCDWQ determined that discharge locations to the New Hope Arm of Jordan Lake or the Cape Fear River/Haw River above Buckhorn Dam are infeasible. Due to required further evaluation related to the Harris Lake/Utley Creek discharges, this option may not meet the project purpose and need. Therefore the only feasible discharge location is the Cape Fear River below Buckhorn Dam. More detail is provided in Appendix B-7 of the Western Wake Regional Wastewater Management Facilities DEIS.

4.1.3 WRF Site Alternatives

The Western Wake Partners conducted preliminary investigations to identify areas in western Wake County that may be suitable for construction of a new regional WRF. The Site would also accommodate the effluent pump station and portions of the Beaver Creek Force Main and the Holly Springs effluent force main. Land area requirements were defined for the new facility, including a 200-foot forested buffer around the site perimeter to minimize potential impacts to neighboring propertiefs from odor, visual appearance, noise, and light. Areas that could be suitable sites for a new WRF were identified, considering physical feature data such as:

§ 100-year floodplain location

§ Wetland area locations

§ Perennial and intermittent stream locations

§ Allowance for 100-foot buffers for streams

§ Allowance for a 200-foot buffer around site

§ Topographic features

In addition to consideration of physical feature data, information and data from previously prepared reports was considered. As a result of the preliminary investigations, 30 locations in Wake and Chatham Counties were identified as potentially suitable sites for a new WRF. The 30 sites are depicted on Figure 4-1. Additional detail on the site identification history can be found in Appendix B-6 of the Western Wake Regional Wastewater Management Facilities DEIS.

During the screening process, Sites 11 and 12 were combined into one site – Site 11/12. These sites were combined because they are adjacent to each other and the combined site boundary resulted in a more viable potential site based on size and location between an existing road and Jordan Lake. Sites 21 and 23 were combined as well to achieve a more viable potential site (Sites 21 and 23 were also evaluated individually).

Initial Screening Analysis – The purpose of the initial screening analysis was to identify those WRF sites to be eliminated based on a single factor. Seven factors were identified and applied to the 30 candidate WRF sites to determine which sites would be eliminated during the initial screening and dismissed from further consideration. As part of this process, sites that did not have 160 acres remaining after considering these factors were also eliminated. It was determined that 160 acres were needed to accommodate the site facilities with a 200-foot perimeter buffer and to provide space to avoid site-specific features such as streams and wetlands on site. Each screening step is summarized below:

1. Site Development – Several sites were developed or someone had obtained site-specific development approvals by local towns or counties. These sites are no longer considered practicable because the cost to acquire the property is expected to be much higher than similar undeveloped or sparsely developed property. When developed or approved for development land was removed from the sites, less than 160 acres of land remained for Sites 2, 4, 5, 10, and 27. These sites were eliminated as alternatives.

2. Wastewater Management Option – The thirty sites were identified prior to selection of the wastewater management option. Siting a WRF in the lowest elevation of a service area facilitates gravity flow rather than pumping, reduces the length of raw wastewater pipelines which reduces energy use, costs, and environmental impacts. Sites 1, 2, 3, 4, 5, 6, 7, 27, 28, and 29 would require the greatest amount of pumping or are located outside the service area. Each of these sites was eliminated from further analysis.

3. Shearon Harris Lake Level – Progress Energy is planning to build and operate two new reactors at the HNP. The water surface of Harris Lake would need to be raised approximately 20 feet (i.e., to an elevation of 240 feet above mean sea level Mean Sea Level (MSL)) to support the two additional reactors. In addition, Progress Energy needs to account for a 50-foot buffer around the lake and land needed for mitigation. Progress Energy has indicated that it would not grant utility easements to local governments below an elevation of 260 feet above MSL. Sites 18, 22, 23, 24, and 29 did not contain 160 acres after land below an elevation of 260 feet above MSL was removed. These sites were eliminated from further analysis.

4. Sites Not Located in Wake County – Since the service area is located in Wake County, it is appropriate the WRF be located in Wake County. North Carolina General Statutes require Chatham County approval prior to procuring property in that County. Sites 1, 5, 6, and 11/12 are located in Chatham County and were eliminated from further evaluation.

5. Floodplain – NCDENR discourages the construction of wastewater treatment facilities in the floodplain. Sites that did not contain at least 160 acres after the 100-year floodplain was removed (Sites 2, 4, 10) were eliminated from further evaluation. Site 9 was also eliminated; it had 170 acres remaining after the floodplain was developed, but 58 acres were already removed due to development leaving approximately 126 acres on the site.

6. Presence of Threatened and Endangered Species – To avoid impacts to federally endangered and threatened species, sites were evaluated for the presence of protected species. Federally protected species were not located on a WRF site alternative, and no sites were eliminated using this factor.

7. Presence of Sensitive Land Uses on Site – Sensitive land uses were defined as cemeteries, schools, daycare facilities, retirement facilities, hospitals and churches. No known sensitive uses were found on any site; no sites were eliminated based on this criterion.

Intermediate Screening Analysis – Intermediate screening was accomplished to identify potential WRF sites for detailed analysis. The intermediate screening was performed for the sites that remained after the initial screening analyses. In the Western Wake Regional Wastewater Management Facilities DEIS, Section 2, Table 2-2 identifies the intermediate screening categories.

Appendix B-6 of the Western Wake Regional Wastewater Management Facilities DEIS summarizes the data compiled for each of the criteria for the 12 candidate sites and the proposed project WRF site.

A simplified scoring was developed that would score a site for each criterion based on whether the criterion for that site was better than or worse than the median. If it was better, the site was given a value of “0” for that criterion and if it was worse it was given a value of “1”. This was done for each of the intermediate screening criteria. The values were totaled for each of the sites and sites with the lowest scores were considered the best alternative sites to analyze as alternatives to the proposed project WRF site. Other scoring methodology that was considered was scoring the site minus the 200-foot perimeter buffer or scoring only the practicable area (the area identified by eliminating the perimeter buffer and stream buffers to the extent practicable and then drawn to achieve an area of approximately 50 acres of contiguous area of a reasonable shape while avoiding environmental impacts to the extent practicable) to see how this affected the scoring. Full results for these analyses are found in Appendix B-6 of the Western Wake Regional Wastewater Management Facilities DEIS.

Results of the screening based on the median criteria statistics for the entire site, the site minus the 200-foot perimeter buffer, and the practicable area are shown in Section 2, Table 2-3 of the Western Wake Regional Wastewater Management Facilities DEIS, for a discharge to the Cape Fear River. From the intermediate screening process, Sites 19, 21/23, and 30 were identified to be the best alternative sites for additional detailed analysis in the EIS, as reasonable alternatives to the proposed project WRF site (Site 14). These same sites were also determined to score high if the WRF discharge was to Harris Lake, under the assumption that the Town of Holly Springs would have a separate discharge location into the lake or lake watershed

Based on the intermediate screening analysis, Sites 14, (referenced in Western Wake Regional Wastewater Management Facilities DEIS as proposed project) 19, 21/23, and 30 were carried forward for alternatives analysis.

4.1.4 Pump Station and Transmission Line Alignment Alternatives

West Cary Pump Station –The West Cary Pump Station currently pumps wastewater to the north. Under this project, the flow direction would change to pump waste to the proposed Western Wake WRF site. The pump station was originally sited and designed so that that it could be used as part of the Western Wake Regional Wastewater Management Facilities and accounted for this flow scenario during the site selection process. Expanding the current pump station infrastructure will result in the lowest impacts on the natural and human environment.

Beaver Creek Pump Station – The purpose of the Beaver Creek Pump Station is to receive raw wastewater collected from western Cary and Apex service areas and convey it to the Western Wake WRF for treatment. There were three goals in siting the Beaver Creek pump station:

1. Serve both Reedy Branch and Beaver Creek service areas – having one central pump station to serve both areas reduces environmental and community impacts, and lower construction and maintenance costs.

2. Allow for maximum gravity drainage into the pump station

3. Allow for single-stage pumping to minimize energy use and maintenance costs

Three potential pump station sites were identified that met each of the goals. The sites were evaluated for environmental and community impacts and cost as follows:

1. Southeast Olive Chapel Road site – This site was eliminated from further consideration since a site visit indicated that a natural spring traversed the buildable portion of the site and would be impacted. The site also had multiple property owners and would result in the relocation of one resident.

2. Southwest Olive Chapel Road site – This site is adjacent to the Southeast Olive Chapel Road site and avoids relocation of residents. Two landowners would be impacted. The site is adjacent to the American Tobacco Trail, but buffers should minimize any impacts to the trail. Geotechnical evaluation indicates that rock would be encountered in the final feet of construction. This site also requires more cut volume than the preferred site. This site was also eliminated from further consideration.

3. North Olive Chapel Road site – This site has one property owner and no residents that would need relocation. This site minimizes the depth of the pump station which minimizes the amount of excavation needed and cost. This is the proposed project Beaver Creek Pump Station site, and the location is identical for all WRF site alternatives.

Transmission Line Alignments – The transmission line, (pipelines from West Cary Pump Station to Beaver Creek Pump Station and from Beaver Creek Pump Station to the Western Wake WRF) alignment alternatives were evaluated to minimize impacts to the following:

§ Environment

§ Property owners and residents

§ American Tobacco Trail

§ Federal land

§ Identified historic districts

§ Conflicts with gas lines and power lines

Based on these criteria, transmission line alignments were selected for each of the project components. The transmission line alignments are very similar for each WRF alternative site, but diverge in the vicinity of the WRF sites. If a discharge to Harris Lake is pursued, the effluent transmission lines would still be similar between the project alternatives. They would be different only in the vicinity of each WRF site.

4.1.5 Wastewater Outfall Options

Discharge locations on the Cape Fear River below Buckhorn Dam were evaluated as well as a bank discharge alternative and a diffuser alternative, more detail is provided in Appendix B-9 of the Western Wake Regional Wastewater Management Facilities DEIS.

Consideration was given to aquatic habitat, recreational activities, maintenance and acceptable dilution in the evaluation of Wastewater Outfall Option.

Bank Discharge Structure (Referenced in DEIS as Proposed Project) – The Bank Discharge Structure was chosen as the discharge in the Cape Fear River below Buckhorn Dam. The discharge consists of a single
54-inch pipe discharging at a head wall located along the river bank. The pipe would be partially submerged at normal river levels and completely submerged at higher river levels.

Alternatives considered but discarded include:

Diffuser Alternative – A diffuser type outfall was also considered. Wildlife agencies had concern that during low flows, the diffuser may cause obstructions in the river and cause dry areas downstream thereby impacting aquatic habitat. A diffuser could also impact recreation on the river. The individual riser pipes on the preliminary engineering drawings indicated they would extend approximately three feet above the river bottom which could present a navigation hazard to recreational boaters. A diffuser design would require more maintenance than a bank discharge. Because the river is shallow and the riser pipes extend above the river bottom, there is concern regarding damage from floating debris. A bank discharge would not be susceptible to floating debris.

Harris Lake Alternative – Originally a discharge to Harris Lake was considered, but Progress Energy indicated that it would not support a discharge near its intake structure in the lake. Their intake location is in Thomas Creek. Progress Energy’s blowdown discharge is located in the mainstem of the lake near the Buckhorn Creek arm of the lake. Additional investigation of a Harris Lake discharge is ongoing in cooperation with Progress Energy. Due to schedule impacts this alternative may not meet the projects purpose and need.

4.1.6 Summary of Project Alternatives

Based on the alternatives analysis summarized above, the following project alternatives were brought forward for detailed analysis. All are regional wastewater management options that include a WRF that would treat wastewater from Apex, Cary, Morrisville, and RTP South with Holly Springs sharing the outfall line to the Cape Fear River below Buckhorn Dam. The project alternatives all include the same location for the West Cary Pump Station, Beaver Creek Pump Station, and the large portions of the transmission line alignments are the same. Each project alternative includes a different WRF site and piping around each plant site.

Proposed Project (WRF Site 14) – Site 14 is a 237-acre site located north of US 1 and South of Old US1 in Western Wake County, close to the community of New Hill. It is located in an area between Shearon Harris Road to the West and New Hill Holleman Road to the east. Approximately 62.1 acres of the 237-acre site would be used for the proposed facilities. This term includes all infrastructure associated with Site 14 including the West Cary Pump Station, West Cary Force Main, West Reedy Branch Gravity Sewer, Beaver Creek Pump Station, Beaver Creek Force Main, WRF located on Site 14, Effluent Pump Station, Effluent Force Main, and Effluent Outfall, Apex Beaver Creek Gravity Sewer, Cary Green Level Force Main and Gravity Sewer, Cary Indian Creek Force Main and Gravity Sewer, and Holly Springs Effluent Force Main (see Figure 4-2).

Project Alternate A (WRF Site 19) – This term includes all infrastructure associated with Site 19 including the West Cary Pump Station, West Cary Force Main, West Reedy Branch Gravity Sewer, Beaver Creek Pump Station, Beaver Creek Force Main, WRF located on Site 19, Effluent Pump Station, Effluent Force Main, and Effluent Outfall, Apex Beaver Creek Gravity Sewer, Cary Green Level Force Main and Gravity Sewer, Cary Indian Creek Force Main and Gravity Sewer, and Holly Springs Effluent Force Main. Much of the infrastructure is identical to the proposed project with exceptions of the WRF site location, effluent pump station location, sections of the effluent transmission line, sections of the Beaver Creek Force Main, and sections of the Holly Springs Effluent Force Main (see Figure 4-3).

Project Alternate B (WRF Site 21/23) – This term includes all infrastructure associated with Site 21/23 including the West Cary Pump Station, West Cary Force Main, West Reedy Branch Gravity Sewer, Beaver Creek Pump Station, Beaver Creek Force Main, WRF located on Site 21/23, Effluent Pump Station, Effluent Force Main, and Effluent Outfall, Apex Beaver Creek Gravity Sewer, Cary Green Level Force Main and Gravity Sewer, Cary Indian Creek Force Main and Gravity Sewer, and Holly Springs Effluent Force Main. Much of the infrastructure is identical to the proposed project with exceptions of the WRF site location, effluent pump station location, sections of the effluent transmission line, sections of the Beaver Creek Force Main, and sections of the Holly Springs Effluent Force Main (see Figure 4-4).

Project Alternate C (WRF Site 30) – This term includes all infrastructure associated with Site 30 including the West Cary Pump Station, West Cary Force Main, West Reedy Branch Gravity Sewer, Beaver Creek Pump Station, Beaver Creek Force Main, WRF located on Site 30, Effluent Pump Station, Effluent Force Main, and Effluent Outfall, Apex Beaver Creek Gravity Sewer, Cary Green Level Force Main and Gravity Sewer, Cary Indian Creek Force Main and Gravity Sewer, and Holly Springs Effluent Force Main. Much of the infrastructure is identical to the proposed project with exceptions of the WRF site location, effluent pump station location, sections of the effluent transmission line, sections of the Beaver Creek Force Main, and sections of the Holly Springs Effluent Force Main (see Figure 4-5).

4.1.7 Selected Project Alternative

As noted in Section 1 and as shown in Figure 1-1, the proposed Western Wake Regional Wastewater Management Facilities Project includes the following infrastructure:

§ Western Wake Water Reclamation Facility (Western Wake WRF Site 14)

§ Northwest Cary Force Main Diversions

· Cary Green Level Force Main and Gravity Sewer (Cary Western Service Area to
West Cary Pump Station)

· Cary Indian Creek Force Main and Gravity Sewer (Cary Western Service Area to
West Cary Pump Station)

§ Western Wake Influent Conveyance Facilities

· West Cary Pump Station (modification only)

· West Cary Force Main (West Cary Pump Station to West Reedy Branch Gravity Sewer)

· West Reedy Branch Gravity Sewer (West Cary Force Main to Beaver Creek Pump Station)

· Apex Beaver Creek Gravity Sewer (Apex Service Area to Beaver Creek Pump Station)

· Beaver Creek Pump Station

· Beaver Creek Force Main (Beaver Creek Pump Station to Western Wake WRF)

§ Holly Springs Effluent Facilities Pump Station and Force Main
(Utley Creek WWTP to the WRF)

§ Western Wake Effluent Conveyance Facilities

· Western Wake WRF Effluent Pump Station

· Western Wake WRF Effluent Force Main and Outfall (to Cape Fear River)

The Project will involve the construction of a regional wastewater system that includes a single WRF to serve the Towns of Apex, Cary, and Morrisville as well as RTP South. The Western Wake WRF will be constructed in two phases to a proposed capacity of 30 MGD.

The Wastewater Management Option chosen is part of Alternative 2 - Solution D, as described on page 4-2. This is a regional system alternative. This alternative is justified based on the cost and impacts, and fulfills NCDWQ’s request that Western Wake communities explore a regional approach to meet future wastewater capacity needs.

The Discharge Location Alternative chosen is the Cape Fear River below Buckhorn Dam, as described on page 4-3. This discharge location best addressed concerns for both water quality issues and nutrient enrichment to an impaired water body. The Town of Holly Springs Utley Creek WWTP has already been approved to expand to 8 MGD and will share the 38 MGD outfall to the Cape Fear River.

The WRF Site Alternative chosen is Site 14. Site 14 is a 237-acre site in western Wake County, with 62.1 acres of the site being used for the proposed facilities. This site was selected as the most feasible site alternative as determined by detailed evaluations which are described in Section 2.5 of the Western Wake Regional Wastewater Management Facilities DEIS.

The Wastewater Outfall Option chosen is a bank discharge structure, as described on page 4-7. This outfall option was selected due low maintenance, low susceptibility to floating debris, minimal obstruction to the Cape Fear River, and cost.

4.2 Biosolids Disposal Alternatives

The method for biosolids disposal as presented in the Western Wake Regional WRF Preliminary Design Report prepared December 2006 by ARCADIS and CH2MHill (Appendix G) is to utilize dewatering and truck loading processes coupled with offsite composting. The biosolids handling facility at the Western Wake WRF will include waste activated sludge (WAS) thickening, 20-day aerated holding, and solids dewatering. Additional information concerning this biosolids disposal approach may be found in the Western Wake Regional WRF Preliminary Design Report prepared December 2006 by ARCADIS and CH2MHill (Appendix G).

An alternative method for disposal is the use of biosolids heat dryer technology. The feasibility of this option is being evaluated. Sludge drying creates a smaller volume of Class A biosolids, according to EPA requirements, that can be land applied to areas such as parks, forested land, and golf courses with few restrictions. Sludge drying also makes containment more practical and helps to limit odor concerns. The reduced volume minimizes biosolids handling, hauling, and disposal. Additional information about the handling of biosolids at the Western Wake WRF can be found in the Technical Memorandum entitled Evaluation of Sludge Dryer and Dewatering Facilities at the Western Wake Regional Water Reclamation Facility prepared by ARCADIS and CH2M HILL in March 2008 (Appendix H). Both biosolids facilities alternatives are planned to be designed and bid as alternates. Based on economic evaluations considering bids received and other factors the decision on which alternatives to implement will be made.

4.3 Design Information

Design information for the Western Wake Wastewater Management Facilities is summarized in this section.

4.3.1 Western Wake Wastewater Management Facilities

Western Wake Water Reclamation Facility – The WRF will consist of liquid treatment facilities, solids handling facilities, two chemical feed systems, and an Operations and Maintenance Building.
Preliminary WRF Site layouts for the Proposed Project (Site 14), Alternate A (Site 19), Alternate B (Site 21/23), and Alternate C (Site 30) are presented in Figures 4-6, 4-7, 4-8, and 4-9 respectively.

The initial treatment facility will consist of mechanical screening, influent flow measurement, and grit removal. Following this will be the secondary treatment facility consisting of an influent splitter box, activated sludge basins, secondary clarifiers, jet aeration and mixing, aeration blowers, and sludge pumping. Tertiary treatment will consist of cloth disk filters, an ultraviolet (UV) disinfection system, effluent flow measurement, post aeration, and plant non-potable water facilities. Sludge thickening by gravity belt filtration, dewatering via centrifuges, dewatered biosolids truck loading, and scum digestion will occur at the solids handling facility. The two chemical feed systems will be a metal salt chemical feed system for chemical phosphorus precipitation, and a sodium hypochlorite chemical feed system to prevent and control filamentous growth. The site layout will be compact, in which all of the plant processes are located in a small central location on the plant site.

The Western Wake Regional WRF Preliminary Design Report was prepared in December 2006 by ARCADIS and CH2MHill (Appendix G), and includes information regarding the design and function of the proposed Western Wake Regional Wastewater Management Facilities. Technical memos provide a detailed description of the individual unit process, and Appendix G contains the plans, site maps, and diagrams of the proposed facility.

Northwest Cary Force Main Diversions – The Kit Creek Pump Station (KCPS) and the Morris Branch Regional Pump Station (MBRPS) currently convey their wastewater from the northwestern portions of the Town of Cary to the Durham County Triangle WWTP. Upon completion of the WRF, the KCPS and the MBPS will convey their wastewater to the West Cary Pump Station, which will pump wastewater southward to the Beaver Creek Pump Station and subsequently to the Western Wake WRF. This will occur in three phases, with the first and second phases designed to meet the 2011 and 2018 projected wastewater flows.

Detailed descriptions and diagrams for this project may be found in the Final Technical Memorandum - Northwest Cary Force Main Diversion Project (Appendix I) prepared in January 2008 by Hazen and Sawyer. Hydraulic calculations are located in Appendices A and B of that Report. Preliminary plan and profile drawings are located in Appendices C and D of that Report.

Influent Conveyance Facilities to the Western Wake WRF – The West Cary Pump Station (WCPS), completed in August 2007, currently serves Morrisville, RTP South, and the western part of Cary by conveying wastewater to the Durham County Triangle WWTP. With the finalization of the Western Wake WRF, the WCPS will be upgraded to a pumping capacity of 31 MGD and will pump wastewater flows to the Beaver Creek Pump Station which will transmit flows to the Western Wake WRF. A preliminary site plan for WCPS is provided in Figure 4-10.

Parallel 36-inch and 24-inch West Cary force mains will be constructed from the West Cary Pump Station to convey wastewater to the West Reedy Branch gravity sewer. The West Reedy Branch gravity sewer will then convey flow to the Beaver Creek Pump Station. Both force mains are slated for construction in Phase I.

The Beaver Creek Pump Station will collect wastewater from the West Cary Pump Station, as well as wastewater flows from White Oak Creek, Reedy Branch, and Beaver Creek service areas in the Town of Apex and will pump them to the Western Wake WRF via parallel 42-inch and 36-inch Beaver Creek force mains. A preliminary site layout for the Beaver Creek Pump Station is provided in Figure 4-11.

(The 36-inch force main may be constructed in Phase II.) The Beaver Creek Pump Station is scheduled for construction such that start-up occurs in 2011. The Beaver Creek Pump Station will have a firm capacity of 40 MGD in Phase I and will be designed for a firm capacity of 58 MGD in Phase II.

Additional information regarding the influent to the Western Wake WRF and the detailed design of the Beaver Creek Pump Station and the upgrade to the West Cary Pump Station may be found in Section 1 (Technical Memorandum No. 1) of the Influent Conveyance Facilities Preliminary Design Report prepared in August 2008 by Hazen and Sawyer (Appendix J).

Preliminary design information regarding the influent conveyance lines, the West Cary force main, the West Reedy Branch gravity sewer, and the Beaver Creek force main can be found in Sections 2, 3, and 5, respectively (Technical Memorandums No. 2, 3, and 5) of the Influent Conveyance Facilities Preliminary Design Report prepared in August 2008 by Hazen and Sawyer (Appendix J).

Holly Springs Utley Creek WWTP Effluent Line to Western Wake WRF – The Utley Creek WWTP serves the Town of Holly Springs and currently discharges into Utley Creek and Harris Lake as shown in Figure 1-1. Utley Creek WWTP will convey its effluent to the Western Wake WRF when it begins operation, where the effluent will be conveyed into the Cape Fear River. The effluent pump station to be constructed at Utley Creek WWTP is being designed for a firm capacity of 18.1 MGD with four pumps. Approximately seven miles of 36-inch force main will be constructed to transmit the effluent from Utley Creek WWTP to the Western Wake WRF.

Additional details about the Utley Creek WWTP effluent to the Western Wake WRF can be found in Section 4.8 of the Town of Holly Springs Utley Creek Wastewater Treatment Plant 201 Facility Plan Amendment prepared in August 2006 by Davis Martin Powell and Green Engineering (Appendix E).

Effluent Conveyance Facilities from the Western Wake WRF to the Cape Fear River (Below Buckhorn Dam) – An effluent pump station and force main at the Western Wake WRF will convey flows from the Western Wake WRF and the Holly Springs’ Utley Creek WWTP to the designated discharge point on the Cape Fear River, below Buckhorn Dam. This force main will be comprised of approximately 62,000 feet (11.75 miles) of a single 60-inch force main that will be capable of conveying peak flows for both Phase I and Phase II to meet projected future flows.

More information about the effluent force main, including detailed descriptions, design schematics, and flow analysis, can be found in the Effluent Conveyance Facilities Preliminary Design Report prepared in August 2008 by Hazen and Sawyer (Appendix K).

4.3.2 Critical Design Issues

There are a few critical issues related to the Western Wake WRF, including noise, odor, light, and building height. Most of these issues have been resolved. However, there are a few issues still being evaluated to improve the overall project between the current design of the Western Wake WRF and the proposed approaches in the Western Wake Regional Wastewater Management Facilities DEIS. These issues are noted below.

Solids Treatment and Disposal – The current design for the solids train of the Western Wake WRF includes a solids aerated holding tank. The Western Wake Regional Wastewater Management Facilities DEIS indicates that this tank would be covered and treated for odors. The Partners are presently conducting an economic evaluation to determine the best option for handling solids treatment and disposal, including the option of eliminating the biosolids aerated holding tanks. This evaluation also includes a dryer option that significantly reduces the volume of on-site biosolids storage making containment more practical and helping to limit odor concerns. The reduced volume minimizes biosolids handling, hauling, and disposal. Therefore, in order to facilitate permitting and construction of the liquid treatment train, the Partners are proceeding with design of the solids train without odor control.

Access Road Stream Crossing – The stream crossing design for Site 14 currently uses conventional culverts. Section 4.1.1.2.1. of the Western Wake Regional Wastewater Management Facilities DEIS currently indicates that the streams will be crossed with bottomless culverts or bridges. This design consideration is currently under evaluation. Additional information regarding the design of bottomless culverts may be found in the Western Wake WRF Site 14 Arch Culvert Options and Preliminary Costs Memorandum by Brown and Caldwell dated August 18, 2008 (Appendix L).

4.4 Open Space/Recreational Opportunities

Project-specific mitigation opportunities have been identified on the proposed Western Wake WRF site that would improve the water quality in Jordan Lake and Harris Lake. One potential opportunity is the preservation of a 200 foot forested buffer along the edge of the site along with two additional conservation areas, one on the north and one on the south edge of the property. This would encompass 95 acres of preservation area, including stream, wetland, forest, and upland areas. Another potential opportunity is to establish fringe wetlands around a pond that already exists on the site, which could be used for wildlife habitat enhancements. Further field work must be conducted to verify these potential opportunities.

Further information can be found in the Preliminary Direct Impacts Mitigation Strategies for Western Wake Wastewater Management Facility Proposed Project prepared by Brown and Caldwell dated October 2008
(Appendix M).

4.5 Collection Systems

There are generally no collections systems included in this Project. The Partners are individually responsible for constructing collection systems in their jurisdictions to collect and convey wastewater to the Western Wake Wastewater Management Facility Influence Conveyance System separately from this project.

However, a minor water distribution system and wastewater collection system will be constructed as part of the WRF located on Site 14 (Proposed Project), its service area is shown in Figure 4-12. If the Western Wake WRF is not located on Site 14, then these collection systems will not be constructed. More information is contained in the Site 14 Water and Sewer Policy (Appendix N).

Site 14 Water System – It is expected that the water system will consist of a water distribution pipeline that will loop through the affected area starting and terminating at New Hill-Holleman Road. The capital costs for the new water distribution system will include all required land acquisition, pipelines, valves, remote-read automatic meters, pressure-reducing devices, disconnection of onsite wells, surveying, engineering and inspection services and final connection of each dwelling unit on each property to the new water distribution system.

Site 14 Sewer System –It is expected that the sewer system will consist of a gravity sewer system that will discharge to a wastewater pumping station owned and operated by the Town of Apex. The new wastewater collection system will include all required land acquisition, pipelines, manholes, surveying, engineering and inspection services, disconnection and decommissioning of existing septic tanks and final connection of each dwelling unit on each property to the new wastewater collection system.

4.6 Transmission Interceptors

Transmission interceptors were evaluated as an alternative to pump effluent from the Kit Creek Pump Station to the Morris Branch Pump Station, but this alternative was not recommended due to the insufficient pipe size of the existing Morris Branch and Panther Creek interceptors. Additional information regarding this alternative can be found in the Final Technical Memorandum - Northwest Cary Force Main Diversion Project, by Hazen and Sawyer dated January 2008 (Appendix I).

Transmission interceptors associated with the Beaver Creek and West Reedy Branch sanitary sewer are documented in the Influent Conveyance Facilities Preliminary Design Report prepared in August 2008 by Hazen and Sawyer (Appendix J).

western wake regional
Wastewater Management facilities
engineering report

5. Present Worth Analysis

The following section provides the cost and present worth analysis information for the four project alternatives as presented in Section 4.1.6. These four wastewater management facilities alternatives are: Proposed Project (WRF Site 14), Project Alternate A (WRF Site 19), Project Alternate B (WRF Site 21/23), and Project Alternate C (WRF Site 30). The proposed project and alternatives are further documented in Section 2 of the Western Wake Regional Wastewater Management Facilities DEIS. Land application alternative is not included in the present worth analysis as it was dismissed. The amount, cost and availability of land required in addition to other factors make land application infeasible (See Section 4 Alternatives Analysis for more detail).

The Western Wake WRF structures will remain relatively the same for all project alternatives. The WRF cost items that differ between the alternatives (alternative WRF sites) include the length of the access road, earthwork, site clearing, and yard piping. Construction costs associated with the West Cary Pump Station and the Beaver Creek Pump Station are the same for all four project alternatives, as the costs are not affected by the geographic location of the Western Wake WRF site. Costs that vary between the project alternatives because of the different WRF geographic locations are the Beaver Creek Force Main and Holly Springs Effluent Force Main conveying flow to the Western Wake WRF, and the WRF Effluent force main to convey from the Western Wake WRF to the Cape Fear River Discharge.

Capital Costs (including patent fees, engineering costs, startup services, operation and maintenance manual, and land and easement costs, and 2 percent SRF loan closing fee), Operations and Maintenance Costs, Replacements Costs, and Salvage Values for each of the individual facility components are summarized within the present worth analysis for each of the four project alternatives. The present worth analyses for the Proposed Project (WRF Site 14), Project Alternate A (WRF Site 19), Project Alternate B (WRF Site 21/23), and Project Alternate C (WRF Site 30) are provided in Tables 5.2, 5.3, 5.4, and 5.5, respectively. They are based on a 20 year planning period and the US EPA discount rate of 4.875 percent. Table 5.1 below summarizes the results of analysis. The Proposed Project (WRF Site 14) has the lowest present worth cost.

Table 5.1. Present Worth Analysis Summary
Project Facilities	Proposed Project	Project Alternate A	Project Alternate B	Project Alternate C
Project Facilities	(WRF Site 14)*	(WRF Site 19)	(WRF Site 21/23)	(WRF Site 30)
Capital Cost	$329,347,000	$346,727,000	$340,492,000	$334,956,000
Operations and Maintenance Cost	$165,796,000	$168,406,000	$168,799,000	$165,872,000
Replacement Cost	$25,675,000	$27,013,000	$26,500,000	$25,902,000
Salvage Value	($700,000)	($720,000)	($693,000)	($712,000)
Total Estimated Present Worth**	$520,118,000	$541,426,000	$535,098,000	$526,018,000
*Partners Preferred Site.
**Total estimated Present Worth is rounded to nearest $1,000.

Table 5.2. Proposed Project (WRF Site 14) – Present Worth Analysis
		Estimated Cost in 2008 Dollars	Present Worth based on 20 years and EPA Rate of 4.875%
Capital Cost
	West Cary Pump Station	$13,191,000
	Beaver Creek Pump Station	$16,686,500
	Influent Lines:
	West Cary Force Main	$10,349,800
	West Reedy Branch Gravity Sewer	$10,178,000
	Beaver Creek Gravity Sewer, Trunk Sewer, & Tunnel	$6,327,500
	Beaver Creek Force Main	$24,857,000
	Cary Green Level Gravity Sewer and FM	$9,500,000
	Cary Indian Creek Gravity Sewer and FM*	N/A
	Apex - Beaver Creek Gravity Sewer	$4,830,000
	Effluent Lines:
	WRF Effluent Force Main and Outfall	$36,480,220
	Holly Springs Effluent FM (on WRF Site)	$755,000
	Holly Springs Effluent PS and FM	$12,980,000
	WRF Site:
	WRF (Plant)	$130,000,000
	WRF Effluent Pump Station	$8,600,000
	Water and Sewer Extension Policy (Site 14 only)	$2,515,961
	Patent Fees	$0
	Engineering	$27,424,170
	Start-up	Included in First Year O&M
	Operation and Maintenance Manual	Included in Engineering
	Land and Easements	$13,271,843
	2% SRF Closing Fee (on $70 million loan)	$1,400,000
	Total Capital Cost	$329,346,994	$329,347,000
Operations and Maintenance Cost (dollars/year)
		1st year only	20-year buildout
	West Cary Pump Station	$353,127	$6,348,000
	Beaver Creek Pump Station	$535,618	$9,566,000
	Influent Lines:
	West Cary Force Main	$103,498	$1,304,000
	West Reedy Branch Gravity Sewer	$101,780	$1,282,000
	Beaver Creek Gravity Sewer, Trunk Sewer, & Tunnel	$63,275	$797,000
	Beaver Creek Force Main	$248,570	$3,131,000
	Cary Green Level Gravity Sewer and FM	$95,000	$1,197,000
	Cary Indian Creek Gravity Sewer and FM*	N/A	N/A
	Apex - Beaver Creek Gravity Sewer	$48,300	$608,000
	Effluent Lines:
	WRF Effluent Force Main and Outfall	$364,802	$4,595,000
	Holly Springs Effluent FM (on WRF Site)	$7,550	$95,000
	Holly Springs Effluent PS and FM	$169,576	$2,136,000
	WRF Site:
	WRF (Plant)	$5,173,616	$128,462,000
	WRF Effluent Pump Station	$111,743	$5,958,000
	Water and Sewer Extension Policy (Site 14 only)	$25,160	$317,000
	Total Operations and Maintenance Cost	$7,401,615	$165,796,000
Replacement Cost (at end of 20-year useful life)**
	West Cary Pump Station	$3,297,750	$1,273,000
	Beaver Creek Pump Station	$4,171,625	$1,610,000
	Influent Lines:
	West Cary Force Main	$2,069,960	$799,000
	West Reedy Branch Gravity Sewer	$2,035,600	$786,000
	Beaver Creek Gravity Sewer, Trunk Sewer, & Tunnel	$1,265,500	$488,000
	Beaver Creek Force Main	$4,971,400	$1,919,000
	Cary Green Level Gravity Sewer and FM	$1,900,000	$733,000
	Cary Indian Creek Gravity Sewer and FM*	N/A	N/A
	Apex - Beaver Creek Gravity Sewer	$966,000	$373,000
	Effluent Lines:
	WRF Effluent Force Main and Outfall	$7,296,044	$2,816,000
	Holly Springs Effluent FM (on WRF Site)	$151,000	$58,000
	Holly Springs Effluent PS and FM	$3,245,000	$1,252,000
	WRF Site:
	WRF (Plant)	$32,500,000	$12,544,000
	WRF Effluent Pump Station	$2,150,000	$830,000
	Water and Sewer Extension Policy (Site 14 only)	$503,192	$194,000
	Total Replacement Cost	$66,523,071	$25,675,000
Salvage Value (at end of 20-year useful life)***
	West Cary Pump Station	($131,910)	($51,000)
	Beaver Creek Pump Station	($166,865)	($64,000)
	Influent Lines:
	West Cary Force Main	$0	$0
	West Reedy Branch Gravity Sewer	$0	$0
	Beaver Creek Gravity Sewer, Trunk Sewer, & Tunnel	$0	$0
	Beaver Creek Force Main	$0	$0
	Cary Green Level Gravity Sewer and FM	$0	$0
	Cary Indian Creek Gravity Sewer and FM	N/A	N/A
	Apex - Beaver Creek Gravity Sewer	$0	$0
	Effluent Lines:
	WRF Effluent Force Main and Outfall	$0	$0
	Holly Springs Effluent FM (on WRF Site)	$0	$0
	Holly Springs Effluent PS and FM	($129,800)	($50,000)
	WRF Site:
	WRF (Plant)	($1,300,000)	($502,000)
	WRF Effluent Pump Station	($86,000)	($33,000)
	Water and Sewer Extension Policy (Site 14 only)	$0	$0
	Total Salvage Value	($1,814,575)	($700,000)
Total Estimated Present Worth – Proposed Project (WRF Site 14)****			$520,118,000
*The Indian Creek Gravity Sewer and FM are projected to be constructed beyond 2018 (in Phase III), and therefore are not included in this estimate.
**Refurbishment cost estimated 20% of Capital Cost for pipelines. Replacement cost is estimated at 25% of Capital Cost for pump stations and treatment plants.
***Pipelines are considered to have zero salvage value at end of useful life. Salvage value is estimated to be 1.0% of Capital Cost for pump stations and treatment plants.
***Total estimated Present Worth is rounded to nearest $1,000.

Table 5.3. Project Alternate A (WRF Site 19) – Present Worth Analysis
		Estimated Cost in 2008 Dollars	Present Worth based on 20 years and EPA Rate of 4.875%
Capital Cost
	West Cary Pump Station	$13,191,000
	Beaver Creek Pump Station	$16,686,500
	Influent Lines:
	West Cary Force Main	$10,349,800
	West Reedy Branch Gravity Sewer	$10,178,000
	Beaver Creek Gravity Sewer, Trunk Sewer, & Tunnel	$6,327,500
	Beaver Creek Force Main	$32,474,000
	Cary Green Level Gravity Sewer and FM	$9,500,000
	Cary Indian Creek Gravity Sewer and FM*	N/A
	Apex - Beaver Creek Gravity Sewer	$4,830,000
	Effluent Lines:
	WRF Effluent Force Main and Outfall	$42,655,220
	Holly Springs Effluent FM (on WRF Site)	Included Below
	Holly Springs Effluent PS and FM	$11,231,000
	WRF Site:
	WRF (Plant)	$136,600,000
	WRF Effluent Pump Station	$9,180,000
	Water and Sewer Extension Policy (Site 14 only)	$0
	Patent Fees	$0
	Engineering	$27,424,170
	Start-up	Included in First Year O&M
	Operation and Maintenance Manual	Included in Engineering
	Land and Easements	$14,700,307
	2% SRF Closing Fee (on $70 million loan)	$1,400,000
	Total Capital Cost	$346,727,497	$346,727,000
Operations and Maintenance Cost (dollars/year)
		1st year only	20-year buildout
	West Cary Pump Station	$353,127	$6,348,000
	Beaver Creek Pump Station	$535,618	$9,566,000
	Influent Lines:
	West Cary Force Main	$103,498	$1,304,000
	West Reedy Branch Gravity Sewer	$101,780	$1,282,000
	Beaver Creek Gravity Sewer, Trunk Sewer, & Tunnel	$63,275	$797,000
	Beaver Creek Force Main	$324,740	$4,090,000
	Cary Green Level Gravity Sewer and FM	$95,000	$1,197,000
	Cary Indian Creek Gravity Sewer and FM*	N/A	N/A
	Apex - Beaver Creek Gravity Sewer	$48,300	$608,000
	Effluent Lines:
	WRF Effluent Force Main and Outfall	$426,552	$5,373,000
	Holly Springs Effluent FM (on WRF Site)	Included Below	Included Below
	Holly Springs Effluent PS and FM	$159,881	$2,014,000
	WRF Site:
	WRF (Plant)	$5,173,616	$128,462,000
	WRF Effluent Pump Station	$130,949	$7,365,000
	Water and Sewer Extension Policy (Site 14 only)	$0	$0
	Total Operations and Maintenance Cost	$7,516,336	$168,406,000
Replacement Cost (at end of 20-year useful life)**
	West Cary Pump Station	$3,297,750	$1,273,000
	Beaver Creek Pump Station	$4,171,625	$1,610,000
	Influent Lines:
	West Cary Force Main	$2,069,960	$799,000
	West Reedy Branch Gravity Sewer	$2,035,600	$786,000
	Beaver Creek Gravity Sewer, Trunk Sewer, & Tunnel	$1,265,500	$488,000
	Beaver Creek Force Main	$6,494,800	$2,507,000
	Cary Green Level Gravity Sewer and FM	$1,900,000	$733,000
	Cary Indian Creek Gravity Sewer and FM*	N/A	N/A
	Apex - Beaver Creek Gravity Sewer	$966,000	$373,000
	Effluent Lines:
	WRF Effluent Force Main and Outfall	$8,531,044	$3,293,000
	Holly Springs Effluent FM (on WRF Site)	Included Below	Included Below
	Holly Springs Effluent PS and FM	$2,807,750	$1,084,000
	WRF Site:
	WRF (Plant)	$34,150,000	$13,181,000
	WRF Effluent Pump Station	$2,295,000	$886,000
	Water and Sewer Extension Policy (Site 14 only)	$0	$0
	Total Replacement Cost	$69,985,029	$27,013,000
Salvage Value (at end of 20-year useful life)***
	West Cary Pump Station	($131,910)	($51,000)
	Beaver Creek Pump Station	($166,865)	($64,000)
	Influent Lines:
	West Cary Force Main	$0	$0
	West Reedy Branch Gravity Sewer	$0	$0
	Beaver Creek Gravity Sewer, Trunk Sewer, & Tunnel	$0	$0
	Beaver Creek Force Main	$0	$0
	Cary Green Level Gravity Sewer and FM	$0	$0
	Cary Indian Creek Gravity Sewer and FM	N/A	N/A
	Apex - Beaver Creek Gravity Sewer	$0	$0
	Effluent Lines:
	WRF Effluent Force Main and Outfall	$0	$0
	Holly Springs Effluent FM (on WRF Site)	$0	$0
	Holly Springs Effluent PS and FM	($112,310)	($43,000)
	WRF Site:
	WRF (Plant)	($1,366,000)	($527,000)
	WRF Effluent Pump Station	($91,800)	($35,000)
	Water and Sewer Extension Policy (Site 14 only)	$0	$0
	Total Salvage Value	($1,868,885)	($720,000)
Total Estimated Present Worth – Project Alternate A (WRF Site 19)****			$541,426,000
*The Indian Creek Gravity Sewer and FM are projected to be constructed beyond 2018 (in Phase III), and therefore are not included in this estimate.
**Refurbishment cost estimated 20% of Capital Cost for pipelines. Replacement cost is estimated at 25% of Capital Cost for pump stations and treatment plants.
***Pipelines are considered to have zero salvage value at end of useful life. Salvage value is estimated to be 1.0% of Capital Cost for pump stations and treatment plants.