1-0982-025-01 TWDB EID DRAFT.pdf

Federal Environmental Review Environmental Information Document

To be used for projects receiving funding from the Clean Water State Revolving Fund or the Drinking Water State Revolving Fund

TWDB-0801

5/22/2015

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Table of Contents

Section 1: General Information

Section 2: List of Attachments

Section 3: Project Description

Preferred Action Alternative

Section 4: Alternative Analysis

No-Action Alternative

Alternative Not Selected

Selection of the Preferred Action Alternative

Section 5: Environmental Settings, Impacts and Mitigation

5.1: Land Use

5.2: Geology

5.3: Soils & Prime and Important Farmland

5.4: Water Resources

5.5: Topography and Floodplains

5.6: Wetlands, Streams, and Waters of the United States

5.7: Biological Elements

5.8: Cultural Resources

5.9: Hazardous Materials

5.10: Social Implications & Environmental Justice

5.11: Other Potential Impacts or Requirements

5.12: Secondary and Cumulative Impacts

5.13: Standard Mitigation, Precautionary Measures and Best Management Practices

5.14: Mitigation Measures

5.15: References

Section 6: Public Participation

Section 7: Agency Coordination

Sample Agency Notification Letter

Sample Agency Coordination Letter

Relevant Sections by Agency

Section 8: Certification

Section 9: Appendices

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Section 1: General Information

Authority (Loan Applicant): City of Round Rock

TWDB Project No: 74016

Project Name: Brush Creek East Wastewater Treatment Plant

Capacity Expansion

Counties where project activities will occur: Williamson

Funding Source/ Loan Number:

TWDB CWSRF /

Total Estimated Project Costs:

117,570,000

TWDB Funded Phases: Planning Acquisition

Design Construction

Other Funding Source(s):

The City of Round Rock will contribute from cash or open market financing.

Consultant Project Name/Number

(if applicable):

Primary Contact for questions concerning the EID:

Company: Plummer Associates

Contact Person: Karen Metzler

Mailing Address: 1320 S. University Drive, Suite 300

Fort Worth, Texas 76107

Phone: 682-291-0951

Email: kmetzler@plummer.com

Project Engineer: Company: Plummer Associates

Contact Person: Sheryl Chia

Mailing Address: 8911 N. Capital of Texas Hwy, Suite 1350

Austin, TX 78759

Phone: 512-687-2157

Email: schia@plummer.com

List of Preparers:

1. Karen Metzler

2. Meredith Brashear

3.

4.

5.

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Section 2: List of Attachments

Documents lacking required attachments will not be accepted

Identify the project footprint on all maps.

Maps must have adequate resolution and be at an appropriate scale.

Example project maps are provided online at:

http://www.twdb.texas.gov/financial/instructions/doc/TWDB-1800.pdf

Many of the resources required by the following list of attachments can be acquired for free online. If you are unfamiliar with the resources identified below or are not sure where to find them, please contact your environmental reviewer for assistance.

Map(s): Show existing structures, potential location(s) of new or upgraded structure(s), and areas(s) that will be disturbed by the project, including construction staging area(s). Provide a scale bar, north arrow, and legend.

Label and Describe: Potentially-impacted environment(s) and site feature(s) (e.g., public/private property, developed or landscaped areas, roads, historic properties, wetlands, forested areas, rivers, streams, 100-year floodplain, prime farmland, wild and scenic rivers, protected areas, above and below-ground utilities, U.S. EPA designated sole source aquifer areas, etc.)

Appendix A: Standard Maps

Regional Location Map Page: A-1

USGS Topographic Map(s) for Preferred Alternative Page: A-2

Project footprint or plans/plats Page: A-6

Geologic Map Page: A-3

FEMA Floodplain Map(s) Page: A-4

National Wetlands Inventory Map(s) Page: A-5

Appendix B: Environmental Setting, Impacts and Mitigation Attachments

Appendix B1

Soils & Prime and

Important Farmland

(Section 5.3)

Page: B-

NRCS Soil Survey for Proposed Project Area of Interest (Required)

Map + Table of Soils (Series level)

Map + Table of Hydric Soils

Map + Table of Prime & Important Farmlands

NRCS Farm Impact Rating (If Applicable)

Farm Impact Rating Form Attached N/A

Appendix B2

Wetlands, Streams &

Waters of the U.S

(Section 5.6)

Page: B-

Wetland & Streams Impacts Map (If Applicable)

Wetland & Streams Impacts Map Attached N/A

Wetland Delineation Report (If Applicable)

Wetland Delineation Report Attached N/A http://www.twdb.texas.gov/financial/instructions/doc/TWDB-1800.pdf

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Section 2: List of Attachments

Documents lacking required attachments will not be accepted

Appendix B3

Biological Resources

(Section 5.7)

County List of Rare, Candidate, Threatened and Endangered Species (Required)

USFWS: County List of Federal Candidate, Threatened and Endangered Species

TPWD: County List of State and Federal Rare, Threatened and Endangered Species

Potential Impacts Table

Appendix B4

Cultural Resources

(Section 5.8)

Cultural Resources Report (If Applicable)

Cultural Resources Report Attached N/A

Appendix B5

Hazardous Materials

(Section 5.9)

Hazardous Materials (If Applicable)

Formal Site Assessment Attached N/A

Appendix B6

Social Implications &

Environmental Justice

(Section 5.10)

All maps & reports should be generated through the EPA’s EJ View Website (Required)

EJ View Map (add a 0.5 mile buffer around the construction area)

ACS Summary Report

Census Summary Report

Environmental Report

Census QuickFacts Summary (Required)

City vs. State

County vs. State

Appendix B7

Public Meeting

(Section 6)

Public Meeting Documentation

Publisher’s affidavit and a copy of the Public Meeting Notice

Statement signed by applicant - meeting was held in conformance with the Public

Meeting Notice.

List of witnesses

Written summary of the meeting

MeredithBrashear Text Box X

MeredithBrashear Text Box X

MeredithBrashear Text Box X

MeredithBrashear Text Box X

MeredithBrashear Text Box X

MeredithBrashear Text Box X

MeredithBrashear Text Box X

MeredithBrashear

X

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Section 3: Project Description

Preferred Action Alternative

For the purposes of this document the project site includes all areas that will be disturbed by the project, including construction staging area(s). The project area includes surrounding areas which may, directly or indirectly, be impacted by the project.

1. Background: Briefly describe the existing system (e.g., treatment processes, capacity of treatment plant, annual average and peak demand flows, etc.).

Brushy Creek East (BCE) WWTP is a regional facility that provides wastewater treatment services to portions of

Williamson and Travis Counties. The facility is part of the Brushy Creek Regional Wastewater System (BCRWWS), which includes the Cities of Round Rock, Austin, Cedar Park, and Leander. Originally constructed in 1987 as a joint venture between the Lower Colorado River Authority (LCRA) and the Brazos River Authority (BRA), the plant was later acquired by the municipal partners in 2009. Since 2018, the City of Round Rock has operated and maintained the facility under contract with the partner cities.

The BCE facility has undergone several expansions to meet increasing demand, with major constructed upgrade projects started in 1995, 2005, and most recently in 2020. The treatment capacity will be 30 MGD, with substantial completion of the latest expansion expected in 2026. The facility is authorized to discharge treated effluent into Brushy Creek under Texas Pollutant Discharge Elimination System (TPDES) Permit No.

WQ0010264002. The permit includes four phased capacity limits, culminating in a final permitted average daily flow of 40 MGD and a peak 2-hour flow of 108 MGD.

The existing treatment system includes multiple process trains designed for biological nutrient removal (BNR), tertiary filtration, ultraviolet (UV) disinfection, and post-aeration. The facility currently operates three treatment trains, with Train 3 constructed to accommodate future flows of up to 30 MGD. The plant also includes three (3) influent lift stations, preliminary treatment units, aeration basins, final clarifiers, solids handling systems, chemical storage with dosing equipment, and odor control infrastructure. The most recent upgrade under construction is to add additional tertiary cloth media filters. With a 2-million-gallon reuse storage tank to support the City of Round Rock’s reclaimed water distribution system planned for construction in 2026/2027.

The influent flow to BCE is collected from regional interceptors, including the Brushy Creek Regional Interceptor, Chandler Creek Interceptor, and McNutt Creek Interceptor. Influent is pumped via three lift stations—Influent

Lift Station 1 (ILS 1), Influent Lift Station 2 (ILS 2), and McNutt Lift Station—into the preliminary treatment unit

(PTU), which includes fine screens and grit removal systems. The treated effluent is discharged to Brushy Creek, Segment No. 1244 of the Brazos River Basin. The facility is situated partially within a floodplain regulated by the

Federal Emergency Management Agency (FEMA), with the current 100-year flood elevation established at

648.50 feet in the year 2020. Past expansions have accounted for flood resilience by elevating critical infrastructure and isolating treatment trains hydraulically. Trains 3 and 4 are designed to operate independently from Trains 1 and

2, allowing gravity flow through the entire treatment process even during peak flow and flood conditions.

The BCE plant is experiencing increasing influent loads due to regional growth. Flow projections indicate that the facility will soon reach 75% of its permitted daily flow, triggering the need for planning and implementation of

P a g e | 9 the next expansion phase per Texas Administrative Code (TAC) §305.126. The proposed expansion to 40 MGD will include the addition of a fourth treatment train, upgrades to solids handling and blower systems, a new non-potable water pump station, and electrical infrastructure improvements to support increased capacity and operational reliability.

2. Project Location: Briefly describe the project location (e.g., new undeveloped site, existing treatment plant site, undeveloped portion of an existing site, site adjacent to existing facilities, currently owned, acquisition required, etc.).

The planned expansion will occur on the existing Brushy Creek East wastewater treatment plant site owned by the City of Round Rock.

Latitude/Longitude: (30.526583° N , 97.620733° W)

Project Address (if applicable): 3939 E Palm Valley Blvd, Round Rock, TX 78665

3. Project Need & Purpose: What need does the project address? (e.g., improve water quality, increase capacity, inadequate system or system components, increase treatment due to more stringent effluent limits, linear work, etc.)

The service area—including the cities of Round Rock, Austin, Cedar Park, Leander, and surrounding Municipal

Utility Districts—is experiencing rapid population growth with rising influent flows. Based on TCEQ Rule

§305.126, the City of Round Rock must initiate construction by 2027, as BCE is expected to reach 90% of its permitted average daily flow by 2027, triggering the requirement to commence construction.

This project is not driven by a current compliance violation but is essential to avoid future non-compliance due to capacity limitations and to meet more stringent effluent quality standards on total phosphorus (TP) in the 40

MGD phase.

The expansion will also increase the supply of reuse water by adding 54 MGD of filtration capacity. This increase in reuse water production will allow the City of Round Rock to supply additional reuse water to the service area and add new customers in the future, even though that is outside the scope of this project.

Is the proposed project being pursued in response to a compliance order? No

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4. Project Description: Description should include project costs, design year and design population.

The City of Round Rock, in partnership with the Brushy Creek Regional Wastewater System (BCRWWS), proposes to expand the BCE WWTP from its current capacity of 30 MGD to 40 MGD. This project will begin construction in 2027 and will be completed by September 2030 to meet the demand of the 2040 Round Rock population of 216956. The proposed expansion of additional 10 MGD treatment capacity will include new construction of a fourth treatment train (Train 4) and capacity expansion of areas including Influent Lift Station

2, Preliminary Treatment Unit, Blower Building, Aeration Basin Train 4, Clarifiers Train 4, Scum Pump Station 4, RAS/WAS Pump Station 4, Filter Complex 3, Ultraviolet Disinfection Complex 3 with Effluent Aeration and

Parshall Flume, Non-potable Water Pump Station, Alum Storage and dosing, Dewatering Building

Improvements, Sludge Pump Station, and West Electrical Building. The project is designed to improve operational reliability, enhance nutrient removal performance, and support the City’s reclaimed water program.

The total project will cost $117,570,000, with construction costing $117M.

Is the proposed project part of a larger project? Yes No

If the proposed project is one phase of a larger project, describe the duration and purpose of the larger project.

5. Waste Disposal: Does the project require sludge/soil/waste disposal? Yes No

If yes, identify the location(s) and method(s) of disposal:

Dewatered sludge is hauled to the Sheridan Composting Facility and if needed, off-site to the Williamson

County Landfill. In FY2023, the City incurred over $2 million in hauling and disposal costs.

6. Project Components: Provide a bulleted list (e.g. install 1,000 linear feet of new 6-8 inch pipeline in existing

ROW and easements from the outfall structure in Lake X to the WTP, install new 300,000 gallon ground storage tank at the WTP, demolish existing chemical storage building, etc.).

• Influent Lift Station 2

• Preliminary Treatment Unit

• Blower Building

• Aeration Basin Train 4

• Clarifiers Train 4

• Scum Pump Station 4

• RAS/WAS Pump Station 4

• Filter Complex 3

• Ultraviolet Disinfection Complex 3 with Effluent Aeration and Parshall Flume

• Non-potable Water Pump Station

• Alum Storage and Dosing

• Dewatering Building Improvements

• Sludge Pump Station

• West Electrical Building

• Yard Piping

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7. Project Magnitude:

i. Current population of service area: 119468

ii. Anticipated population of service area in 20 years: 216956

iii. Will the proposed project service the entire population increase? Yes No

8. Project Schedule:

Anticipated Completion of Environmental Review: March 2026

Completion of Acquisition: N/A

Completion of Permitting: March 2026

Completion of Design: March 2026

Start of Construction: Mid 2027

Construction Completion: September 2030

9. Project Costs: Provide an estimate of the cost of the project. $117570000

10. Other Projects: Provide a description of any other projects in progress that may be affected by the proposed project (e.g., TxDOT plans for Road Construction, etc.).

N/A

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Section 4: Alternative Analysis

No-Action Alternative

Environmental Impact Description

Provide a qualitative description of the environmental impacts of the no-action alternative and compare the impacts to that of the preferred alternative. (e.g., WTP would remain out of compliance with TCEQ primary drinking water standards, leaky on-site septic systems would continue to contaminate surface water, etc.)

The no-action alternative would be to do nothing. This option fails to address the pressing issue of capacity limitations at the BCE WWTP, which will receive over 75% of its permitted average daily flow in the near future.

This threshold triggers mandatory planning requirements under TCEQ regulations (30 TAC §305.126). Without expansion, the system risks non-compliance with its TPDES permit, increased likelihood of sanitary sewer overflows, and inability to support continued population growth and development in the service area. During wet weather events, the treatment units will be put at a higher risk of overflow. Overflows would result in untreated or partially treated wastewater will spill from the facility contaminating Brushy Creek and downstream areas. Following an overflow, the city staff will need to repair and restart all treatment units causing further issues with being able to serve the population. Depending upon the extent of overflow, this repair and restart period could vary from weeks for some units to months. During this period, the City would not have access to this plant’s treatment capacity and would need to pump and haul wastewater to other facilities for treatment or rent temporary treatment units, and these are not immediately available.

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Environmental Impact Analysis

Please indicate whether the direct impacts of the no-action alternative on the following resources are greater than, less than or the same as the direct impacts of the preferred alternative on the same resource.

Land Use

Change in land use and land cover is: Greater Less Same

Prime and Important Farmland

Impacts to prime and important farmland are: Greater Less Same

Water Resources

Impacts to surface water quality are: Greater Less Same

Impacts to groundwater quality and quantity are: Greater Less Same

Impacts to floodways or floodplains are: Greater Less Same

Impacts to wetlands are: Greater Less Same

Vegetation and Habitat

Impacts to trust resources are: Greater Less Same

Impacts to wildlife are: Greater Less Same

Impacts to native vegetation is: Greater Less Same

Impacts to endangered species habitat are: Greater Less Same

Impacts to cultural resources or historic properties are: Greater Less Same

Air Quality

Effects on air quality are: Greater Less Same

Impacts to Low-income or Minority Populations are: Greater Less Same

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Secondary and Cumulative Impacts: Considering resources that the no-action alternative will impact, identify any past, present or reasonably foreseeable future projects which impact these same resources. This answer will provide important contextual information.

Secondary:

Wastewater overflows resulting from increased flows and low capacity will contaminate Brushy Creek which is a tributary to the Brazos River. The increase of nutrients in the stream system will result in algae blooms and fish kills, degrading the local ecosystem. Continuous contamination over time will degrade the creek’s ecosystem.

These conditions also pose health risks to the local residents. Previous expansions have reduced the risk of overflows and prevented such issues from occurring.

Cumulative:

During this period, the City would not have access to this plant’s treatment capacity and would need to pump and haul wastewater to other facilities for treatment or rent temporary treatment units, and these are not immediately available. This would put pressure on these systems, which may not be able to meet the need of

Round Rock’s growing population.

Acceptance/Rejection

Alternative: Accepted Rejected

Rationale for Acceptance/Rejection

Discuss the rationale for acceptance/rejection of the no-action alternative, including financial, engineering and environmental considerations (e.g. cost comparison, reliability of alternative, complexity of alternative, significant environmental effects, legal or institutional constraints, etc.):

The no action alternative would significantly constrain responsible population and economic growth within the community. Adequate wastewater infrastructure is a foundational component of sustainable development.

Without sufficient treatment capacity, new residential, commercial, and industrial development would be restricted, limiting the City’s ability to support continued growth, attract investment, and maintain the high quality of life expected by its citizens. This type of limitation and moratorium would cause catastrophic impacts on the local community and would negatively impact employment. The City would be in the position of limiting growth and placing a moratorium on new developments. Additionally, delaying improvements may result in higher future costs and missed opportunities to enhance system efficiency and environmental performance.

Depending upon the extent of overflow, this repair and restart period could vary from weeks for

P a g e | 15 some units to months. During this period, the City would not have access to this plant’s treatment capacity and would need to pump and haul wastewater to other facilities for treatment or rent temporary treatment units, and these are not immediately available. Additionally, this option fails to address the pressing issue of capacity limitations at the BCE WWTP, which will receive over 75% of its permitted average daily flow in the near future.

This threshold triggers mandatory planning requirements under TCEQ regulations (30 TAC §305.126).

The WWTP expansion represents a proactive investment in public health, environmental stewardship, regulatory compliance, and long-term fiscal responsibility, ensuring that the City of Round Rock can continue to serve its community effectively now and into the future. For these reasons, the no action alternative was rejected.

Section 4: Alternatives Analysis Alternative Not Selected

*Attach additional alternative sheets as necessary*

Description

Please provide a description of this alternative:

This alternative is to design and construct a new green-field treatment plant to manage flows beyond the feasible capacities of the 2 WWTP that the City currently has – Brush Creek East (BCE) and Brushy Creek West (BCW).

Alternative still in consideration? *Yes No

*If yes, please note that the level of detail provided for this alternative should be commensurate with the level of detail provided for the preferred alternative presented in this document. Please work with your Environmental

Reviewer to scope this document appropriately in order to prevent project delays.

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*Attach additional alternative sheets as necessary*

Environmental Impact Description

Provide a qualitative description of the environmental impacts (adverse and beneficial) of this alternative and compare the impacts to that of the preferred alternative. Specify temporary versus permanent impacts.

The western portion of the BCRWWS collection system is located within the Edwards Aquifer

Contributing and Recharge zones, therefore, an effluent outfall cannot be permitted within these zones and effluent will need to be discharge via reuse or pumped to a discharge location outside of the Edwards Aquifer zones. Or it might deploy zero discharge treatment processes. Both discharge methods are too expensive. The construction would require land use conversion while the preferred alternative uses an already existing wastewater treatment plant.

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*Attach additional alternative sheets as necessary*

Environmental Impact Analysis

Please indicate whether the direct impacts of the alternative not selected on the following resources are greater than, less than or the same as the direct impacts of the preferred alternative on the same resource.

Land Use

Change in land use and land cover is: Greater Less Same

Impacts to prime and important farmland are: Greater Less Same

Water Resources

Impacts to surface water quality are: Greater Less Same

Impacts to groundwater quality and quantity are: Greater Less Same

Impacts to floodways or floodplains are: Greater Less Same

Impacts to wetlands are: Greater Less Same

Vegetation and Habitat

Impacts to trust resources are: Greater Less Same

Impacts to wildlife are: Greater Less Same

Impacts to native vegetation is: Greater Less Same

Impacts to endangered species habitat are: Greater Less Same

Impacts to cultural resources or historic properties are: Greater Less Same

Air Quality

Effects on air quality are: Greater Less Same

Impacts to Low-income or Minority Populations are: Greater Less Same

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*Attach additional alternative sheets as necessary*

Secondary and Cumulative Impacts: Considering resources that this alternative will impact, identify any past, present or reasonably foreseeable future projects which impact these same resources. This answer will provide important contextual information.

Secondary: Building a new wastewater treatment plant in the Edwards Aquifer Recharge zone increases the risk of contamination to the Edwards Aquifer. Though discharge would be pumped to an area outside of the recharge zone, overflow could still occur and contaminate the surrounding area of the new plant. This contamination would endanger the unique Edwards Aquifer ecosystem and put the population’s health at risk.

Cumulative:

The construction of a new wastewater treatment plant would require additional projects to connect to the City’s current wastewater system. This increases the land and resources required, further impacting the local environment and communities. With the potential project area being in the Edwards Aquifer Recharge zone, any additional construction poses a risk to an important drinking water supply. The high levels of uncertainties would increase risks to the environment, drive up the costs, making the project a burden to Round Rock residents.

Acceptance/Rejection

Alternative: Accepted Rejected

Rationale for Acceptance/Rejection

Discuss the rationale for acceptance/rejection of this alternative, including financial, engineering and environmental considerations:

The location of the new WWTP is unknown and will be based on land availability, regulatory approvals and infrastructure requirements and feasibility, such as the routes of the collection systems and additional lift stations or pumping capacities required.

Additional staff and management of the new WWTP will need to be arranged for. The master planning cost estimation shows that a new WWTP of 10 MGD would cost about $241 Million. Due to the various uncertainties, high cost and high risk for the City, this alternative is not a viable option at this point.

The majority of the BCRWWS is within the Edwards Aquifer Recharge Zone. A very possible location of the new plant will utilize the western portion of the BCRWWS collection system, which is located within the Edwards Aquifer Contributing and Recharge zones. Therefore, an effluent outfall cannot be permitted within these zones and effluent will need to be discharged via reuse or pumped to a discharge location outside of the Edwards Aquifer zones. Or it might deploy zero discharge treatment processes. Both discharge methods are too expensive.

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*Attach additional alternative sheets as necessary*

Section 4: Alternatives Analysis Selection of the Preferred Action Alternative

Discuss the rationale for why the proposed project was chosen as the preferred alternative:

Expanding the BCE WWTP from 30 MGD to 40 MGD has an Engineers Opinion of Probable Construction

Cost (OPCC) of $118 million in capital improvements. It is a cost-effective and timely solution to meet 20-year capacity needs from year 2030 to 2050 for all BCRWWS partner cities, particularly Round Rock and Austin. The project is already at the end of a detailed design phase, which includes construction plans for the new treatment

Train 4. The expansion will ensure compliance with increasingly stringent effluent limits for TP and improve operational reliability. However, the site has limited room for future expansion beyond 40 MGD due to floodplain constraints, and additional upgrades may be needed to fully optimize treatment performance.

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Section 5: Environmental Settings, Impacts and Mitigation

5.1: Land Use

Existing Conditions

Will the project require land use conversion? Yes No

If yes, explain:

Describe current and recent past land use and development on the site and on adjacent lands. Discuss project compatibility with adjacent and nearby land uses.

Before wastewater treatment plant was constructed in 1987 land appeared to be used for agricultural purposes.

Since then the property has been an active wastewater treatment plant.

Will new or expanded utilities, roads, other infrastructure or public services be required to serve the project?

Yes No

If yes, describe additional services needed:

Impacts

Describe direct impacts of the project (adverse and beneficial) on land use. Specify temporary versus permanent impacts.

The project area is on an existing wastewater treatment plant. All land has been previously disturbed and requires no conversion of land use.

Mitigation Measures

Mitigation Measures for Project Environmental Impacts? Yes Not applicable

If yes, list all mitigation measures in Section 5.14.

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5.2: Geology

Existing Conditions

Physiographic

Province:

Gulf Coast Plains Central Texas Uplift Grand Prairie

Edwards Plateau North-Central Plains High Plains

Basin and Range

Are there faults within the project’s area of interest? Yes

No

Is the project located in a Karst or Pseudo-Karst Zone? Yes

No

Include the names and brief descriptions of the geologic formations in the project’s area of interest.

The project site overlies Fluviatile Terrace Deposits and a small portion of Alluvium. In the surrounding area outside of the site there’s Austin Chalk as well.

Fluviatile Terrace Deposits: Terraces along streams, consist of three or more levels which may correspond to coastal Pleistocene units; gravel, sand, silt, and clay in various proportions with gravel more prominent in the older, higher terraces; dolomite, limestone, and chert from the Edwards Plateau; sand mostly quartz.

Alluvium : Floodplain deposts, including indistinct low terrace deposits; clay, silt, sand, and gravel; silt and clay, calcareous to surface, dark gray to dark brown; sand largely quartz; gravel, siliceous, mostly chert, quartzite, limestone, and petrified wood; fluvatile morphology well preserved with point bars, oxbows, and abandoned channel segments.

Austin Chalk: Chalk and marl; chalk mostly microgranular calcite with minor Foraminifera tests and Inoceramus prisms, averages about 85% calcium carbonate, ledge forming grayish white to white; alternates with marl, bentonitic seams locally recessive, medium gray; pyrite nodules common, weather to limonite; thickness 325-420 feet.

Discuss any relevant topographical and geological features (e.g. salt domes, sink holes, shallow limestone formations, karst conditions, cave systems, etc.).

The project area has a gentle slope eastward with no relevant geological features to note.

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5.2: Geology

Impacts

Describe direct impacts of geology on the proposed project. Please elaborate on all items checked “Yes” above:

The construction of the wastewater treatment plant expansion will have little to no impact on the geology of the proposed project area. The pipelines built for this project range from depths of 10 ft to 32 ft below ground level and won’t disturb any relevant geological features.

Mitigation Measures for Project Environmental Impacts? Yes Not applicable

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5.3: Soils & Prime and Important Farmland

Soils

Is soil contamination present? Yes No

Does soil type present any constraints to the project? Yes No

If yes to either above, explain (if redundant with information provided in the Hazardous Materials section reference that section):

Will soil be moved offsite?

If yes, how will it be disposed of?

Will soil become contaminated as a result of the proposed project?

If yes, explain:

Does the project area contain prime and important farmlands?

Yes

No

If yes, does either of the following exemptions apply?

Exempt – corridor subsurface project (e.g., buried water, sewage, and/or electric lines).

Exempt – previously converted site (e.g., existing water and wastewater treatment plant sites).

If the project area contains prime and important farmlands and does not qualify for the exemptions listed above, include a completed version of the NRCS' Farmland Conversion Impact Rating Form AD-1006

Attach Form AD-1006 to Appendix B1

Impacts

Will prime and important farmland be directly impacted by the project? Yes No

Describe direct impacts of the project on prime and important farmland:

The wastewater treatment plant construction will take place on an existing wastewater treatment plant site.

Mitigation Measures for Project Environmental Impacts? Yes Not applicable

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5.4: Water Resources

Existing Conditions

What river basin(s) is the proposed project located in?

Brazos River Basin

What major/minor aquifers are located in the greater project area?

Edwards Aquifer Blacones Fault Zone (subcrop)

Trinity Aquifer (subcrop)

Are any of these a sole source aquifer? Yes No

Water supply(ies): Surface water(s):

Local ponds

Groundwater(s):

Edwards Aquifer (outcrop)

Water Well Projects

Does the project involve the installation of any water wells? Yes No

If yes, provide the depth to ground water, duration and quantity of water to be extracted, and potential affects to the public water supply:

Will the project require test wells? Yes No

Will any existing water well(s) be abandoned? Yes No

If yes, discuss best management practices that will be used to abandon the existing well(s):

Impacts to Water Resources

Will water resources be directly impacted by the project? Yes No

Describe direct impacts (adverse and beneficial) to surface water quality and groundwater quality/quantity

(surface water runoff, erosion, sedimentation, temporary loss of vegetation cover, etc.). Specify temporary versus permanent impacts.

There may be temporary erosion and sediment in runoff due to construction, but project will adhere to all regulations imposed to protect surface water quality. There will be no permanent impacts as a result of this project. There should be no impact to groundwater since the project area is outside of the recharge zones for the two aquifers in the region the Edwards Aquifer and the Trinity Aquifer.

Will the project include new or relocated discharge site(s)? Yes No

Will the project require an amendment to an existing TCEQ discharge permit? Yes No

If yes, discuss the nature of the permit changes:

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5.4: Water Resources

The permit was previously updated for 40 MGD final capacity.

If the project requires a new permit or a permit amendment, list all stream segment(s) found at and immediately downstream of the proposed discharge sites. Source: TCEQ list of stream segments and water quality data.

Stream Segment ID Classification Impaired? Reason for Impairment

Yes No

Yes No

Yes No

Mitigation Measures

Mitigation Measures for Project Environmental Impacts? Yes Not applicable

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5.5: Topography and Floodplains

Topography

Minimum Elevation in Project Area (MSL): Maximum Elevation in Project Area (MSL):

645 ft amsl 664 ft amsl

Briefly describe the topography in the project area (e.g., gently rolling hills, dominant drainage to the west via tributaries to the Brazos River):

Primarily flat with slight slope leading drainage east towards Brushy Creek.

Discuss any relevant topographical features (e.g. playa lakes).

Floodplains & Floodways

Is the project site located in a 100-year floodplain? Yes No Partial

If yes, list all streams with floodplains in project area. Specify whether the project will be located within the 100-year floodplain and/or floodway(s) of these streams.

Stream Project in 100-year floodplain? Project in floodway?

Brushy Creek Yes No Yes No

Yes No Yes No

Do the communities (cities and/or counties) in which the project will be constructed participate in the National Flood Insurance Program?

Yes No Partial

List all participating cities and counties List all non-participating cities and counties

Impacts

Will floodplains or floodways be directly impacted by the project? Yes No

Describe direct impacts of the project (adverse and beneficial) on floodplains and floodways. Specify temporary versus permanent impacts:

The eastern most part of construction area for the wastewater treatment plant expansion overlies the 100 year floodplain . Past expansions have accounted for flood resilience by elevating critical infrastructure and isolating treatment trains hydraulically. Trains 3 and 4 are designed to operate independently from Trains 1 and

2, allowing gravity flow through the entire treatment process even during peak flow and flood conditions.

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5.5: Topography and Floodplains

Mitigation Measures

Mitigation Measures for Project Environmental Impacts? Yes Not applicable

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5.6: Wetlands, Streams, and Waters of the United States

Information included in this template represents baseline information pertinent to the majority of projects.

Regulatory agencies, including the USACE, may require additional information to determine permitting or mitigation requirements.

List all applicable U.S. Army Corps of Engineers permits for the project (general and/or individual):

Will any of the applicable permits require pre-construction notification? Yes No

If yes, which one(s):

Are streams present on the project site or in the project area (perennial, ephemeral, intermittent)?

If yes, list all streams in the project area.

Brushy Creek is a perennial stream that runs by the Brushy Creek East Wastewater Treatment Plant and accepts discharge from the plant.

Are wetlands present on the project site or in the project area? Yes No

If yes, discuss the type and quality of wetlands (e.g., forested palustrine, emergent riverine):

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Has a site wetlands/waters delineation or jurisdictional determination been performed using the applicable

USACE Wetland Delineation Manual*, including regional supplements**?

Yes: If Yes, has it been verified by the USACE? Yes No

No

*Environmental Laboratory. (1987). "Corps of Engineers Wetlands Delineation Manual". Technical Report Y-87-1.

U.S. Army Engineers Waterways Experimental Station, Vicksburg, MS.

**The manual is to be used with the appropriate regional supplement. These supplements and the manual can be found on the following website:

http://www.usace.army.mil/Missions/CivilWorks/RegulatoryProgramandPermits/reg_supp.aspx

If yes, summarize the findings below and attach a copy of the field survey to Appendix B2. If no, describe the basis for above statements regarding presence or absence of wetlands and waters of the U.S..

The Texas inventory of Wetlands did not show any wetlands in the project area. Physical surveying verified there are no wetlands on the property and the land is all previously disturbed.

Impacts

Will wetlands be impacted? Yes No Will streams be impacted? Yes No

Are any of the impacted wetlands/streams in the project area tidally influenced? Yes No

Describe direct impacts of the project (adverse & beneficial) on streams and wetlands (e.g., fill, dredging, dewatering, surface water runoff, other pollutants, etc.). Specify temporary versus permanent impacts.

There may be temporary erosion and sediment in runoff due to construction but project will adhere to all regulations imposed to protect surface water quality. There will be no permanent impacts from this project.

http://www.usace.army.mil/Missions/CivilWorks/RegulatoryProgramandPermits/reg_supp.aspx

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Stream/Wetland Impacts (if applicable) *add rows if needed

This section must be accompanied by a Stream/Wetland Impact Map:

The map must include a topographic background with footprint of the project overlain. Assign a number to each stream/wetland in the project footprint and label each on the map (e.g., S1, S2, W1, W2).

Attach the map to Appendix B2

Stream Impacts:

Include all streams in project footprint even if impact is zero feet

# Keyed to Map

(S1, S2,…)

Temporarily impacted Permanently impacted

All Streams

[linear ft]

Potential Waters of U.S.

(streams only) [linear ft]

All Streams

[linear ft]

Potential Waters of U.S.

(streams only) [linear ft]

Total Stream

Impacts (feet):

Wetland Impacts:

Include all wetlands in project footprint even if impact is zero acres.

# Keyed to Map

(W1, W2,…)

Temporarily impacted Permanently impacted

All Wetlands

[ac]

Potential Waters of U.S.

(wetlands only) [ac]

All Wetlands [ac] Potential Waters of U.S.

(wetlands only) [ac]

Total Wetland

Impacts (acres):

Mitigation Measures for Project Environmental Impacts? Yes Not applicable

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5.7: Biological Elements

Ecoregion: Arizona/New Mexico Mtns. Central Great Plains Texas Blackland Prairies

Chihuahuan Deserts Cross Timbers East Central Texas Plains

High Plains Edwards Plateau Western Gulf Coastal Plain

Southwestern Tablelands Southern Texas Plains South Central Plains

Using USFWS and TPWD County Lists of Rare, Candidate, Threatened and Endangered Species, create a table of potential impacts with the following columns:

(1) Species (common and scientific names), (2) State/federal protection status, (3) Habitat, (4) Presence of

Critical Habitat, (5) Project Site Suitability, and (6) Potential Impacts of Project

Attach the Potential Impacts Table to Appendix B3

Has a biological field survey been performed? Yes No

If yes, summarize the finding below. Attach report to Appendix B3, if applicable – exclude report from publicly available documents to protect location sensitive information.

Are any parks, recreational areas, forest preserves, grassland preserves, wildlife refuges, wild or scenic rivers, karst faunal regions or zones, or nature preserves

(federal, state or local; public or private) in or near the project area?

If yes, list and describe proximity to project site:

Briefly describe the vegetation and wildlife, including aquatic species, present in the project site and project area.

* Do not include protected species addressed in the potential impacts table.

Northern Mockingbird (Mimus polyglottos)

Bluejay (Cyanocitta cristata)

Cedar Elm (Ulmus crassifolia)

Bur oak (Quercus macrocarpa)

China berry (Melia azedarach)

Mowed grass

Impacts

Discuss potential impacts (adverse and beneficial) to trust resources, wildlife and natural vegetation, including habitat. Provide information about the nature, extent, duration and location of the impacts. Specify temporary versus permanent impacts.

* Do not include protected species already addressed in the potential impacts table.

The construction for this project will occur on an existing wastewater treatment plant so impacts to trust resources, wildlife and natural vegetation will be minimal. The previously disturbed site had limited wildlife and vegetation.

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5.7: Biological Elements

If present in or near the project area, discuss potential impacts to any parks, recreational areas, forests preserves, grasslands preserves, wildlife refuges, wild or scenic rivers, karst faunal regions or zones, or nature preserves (federal, state or local; public or private):

N/A

Mitigation Measures

Mitigation Measures for Project Environmental Impacts? Yes Not applicable

5.8: Cultural Resources

Have you notified the State Historic Preservation Officer (SHPO) at the Texas Historical

Commission that you intend to use the NEPA process to comply with Section 106 of the

National Historic Preservation Act?

Yes No

Identify parties that were consulted regarding cultural resources, including Tribal Historic Preservation Officers

(THPO), the federal Advisory Council on Historic Preservation (ACHP), local governments, or any other interested parties.

Has an archeologist and/or an architectural historian performed a desktop review of the proposed project?

Yes No

Identify cultural resources/historic properties (included in or eligible for inclusion in the National Register of

Historic Places) within the proposed project’s area of impact.

Has an archeological and/or architectural survey been conducted? Yes No

If Yes, briefly summarize the results of the report(s) and attach them to Appendix B4, if applicable – exclude report from publicly available documents to protect location sensitive information.

Does the project have the potential to affect significant cultural resources/historic properties?

Yes No

If you have determined that historic properties will not be impacted, explain how this conclusion was reached.

There are no surrounding historic properties to be impacted. Information provided by THC

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5.8: Cultural Resources

Describe direct impacts (adverse and beneficial) of the project on cultural resources/historic properties. Specify temporary versus permanent impacts.

There will be no impacts to cultural resources or historic properties as a result of the construction of this project.

Mitigation Measures for Project Environmental Impacts? Yes Not applicable

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5.9: Hazardous Materials The TWDB does not fund the testing, remediation, removal, disposal, or related work for contaminated or potentially contaminated material.

Is there a Superfund Site in the project area or in an area associated with the proposed work (e.g., Superfund site upstream of project activities in a floodplain)?

Was a site assessment conducted? Yes No

If a formal site assessment was conducted please attach the report and/or data search to Appendix B5.

Attached

Not Applicable

If an informal site assessment was conducted, please briefly describe methods and results. Make sure to identify any potential environmental hazards located on the site due to past site uses (e.g. soil contamination or proximity to nearby hazardous liquid or gas pipelines) :

An Environmental Regulatory Database Report was reviewed for the proposed project. The report did not indicate that there are any Recognized Environmental Condition (REC) on the proposed project site.

Mitigation Measures for Project Environmental Impacts? Yes Not applicable

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5.10: Social Implications & Environmental Justice

Social Implications

Will land acquisition for the project require the use of eminent domain? Yes No

If yes, describe:

Will people or businesses be relocated as a result of this project? Yes No

If yes, describe the extent and nature of the relocations.

Will the project cause an increase in resident’s monthly service rates? Yes No

If yes, provide an estimate of an average monthly residential bill and the anticipated monthly residential increase required to finance the debt.

Average Monthly User Rate: $

Anticipated Increase: $

Will the project require an increase in taxes to finance the debt? Yes No

If yes, provide an estimate of the increase required:

Area Population % Minority % Below the Poverty

Level/ Per Capita Income

State 29,145,505 64.1% 13.4% / $40,752

County: Williamson 617,396 43% 6% / $47,574

City: Round Rock 135,359 50% 7.8% / $50,365

Project Area

(0.5 mile buffer)

2,865 39% 10% / $53,623

Does the project area have a portion of the population, greater than the city, county or state average, who are members of a racial/ethnic minority category or who have incomes less than or equal to the state’s official poverty level?

Yes No

Impacts

Will the project disproportionally impact low-income or minority populations? Yes No

Please explain:

Mitigation Measures for Project Environmental Impacts? Yes Not applicable

X

MeredithBrashear

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5.11: Other Potential Impacts or Requirements

1. Air Quality: Is the project in a maintenance or non-attainment area for any priority air pollutant under the federal Clean Air Act?

Yes No

If yes, describe the impact the project will have on ambient air quality.

2. Scenic Views: Will the project impact scenic views or vistas during construction or operation?

Yes No

If yes, indicate which scenic views or vistas will be impacted and discuss adverse impacts. Specify temporary versus permanent impacts.

3. Traffic: Will construction of this project involve rerouting or controlling traffic? Yes No

If yes, describe traffic changes and how long traffic will be disrupted:

4. Other Potential Impacts: If the project may cause any adverse impacts not addressed by items 1-3, identify and discuss them here (e.g., odor, prevailing winds, noise, blasting, night work, etc.):

No adverse impacts are anticipated from the construction of the WWTP expansion.

Mitigation Measures for Project Environmental Impacts? Yes Not applicable

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5.12: Secondary and Cumulative Impacts

Considering resources that your project will impact, identify any past, present or reasonably foreseeable future projects which impact these same resources. This answer will provide important contextual information.

The BCE facility has undergone several expansions to meet increasing demand, with major constructed upgrade projects started in 1995, 2005, and most recently in 2020. The current treatment capacity is 30 MGD, with substantial completion of the latest expansion expected in 2026. The 40 MGD expansion will have similar impacts to the surrounding area as other expansions have. Because all construction projects occurred on a pre-existing wastewater treatment plant site, the impacts were minimal. Past expansions have accounted for flood resilience by elevating critical infrastructure and isolating treatment trains hydraulically.

Mitigation Measures for Project Environmental Impacts? Yes Not applicable

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5.13: Standard Mitigation, Precautionary Measures and Best Management Practices

Describe any standard mitigation, precautionary measures and best management practices to be used during project construction (e.g., storm water pollution prevention plan, re-vegetation, dust and siltation control, establish original grades in floodplains, etc.).

During the construction project SWPPP standards will be followed with weekly inspections. Past expansions have accounted for flood resilience by elevating critical infrastructure and isolating treatment trains hydraulically. The same care will be taken for the 40 MGD expansion. Additional measures that will be taken are dust control (apply water or approved dust suppressants to exposed soils), restoration of roads after construction, designate and contain concrete washout areas, limit construction activities to permitted working hours unless otherwise approved, protect trees that do not need to be cleared for construction. For this document a field survey was conducted to ensure no impact on aquatic resources or threatened and endangered species.

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5.14: Mitigation Measures

Provide a list of potential adverse impacts of the proposed project and a description of how those impacts will be avoided, minimized, or mitigated. This list will be used to develop conditions for the environmental determination issued by the TWDB. Please ensure the information is consistent with what was provided to regulatory agencies and incorporates applicable agency recommendations. When responding to recommendations provided by regulatory agencies, identify which are feasible and which will not be implemented.

Impact: Recommended/Required by

What Entity? (if applicable)

Mitigation Measures Description:

Example:

Loss of 5…