11 - Wastewater Treatment Plant Engineering ServicesItem No. 11
memorandum
TO: Mayor & City Council
FROM: John Godwin, City Manager
SUBJECT: WASTEWATER TREATMENT PLANT ENGINEERING SERVICES
DATE: May 31, 2019
BACKGROUND:
We have been working with Garver USA in one form or another since October 2013 to help us
plan for, analyze, and ultimately completely rehabilitate our very old and inefficient wastewater
(sewer) treatment plant. In 2014-16 Garver worked with us and the Texas Water Development
Board to explore funding options, completed preliminary investigative work, and also
participated in meetings with the city and a board member, all at no cost to the city. Although
we did not move forward at that time with a formal contract with Garver, at the April 22 city
council meeting of this year, the council instructed staff to pursue a professional services
agreement to provide all necessary engineering and related services to rehabilitate the sewer
plant.
STATUS OF ISSUE: Since that time, we have met and reviewed a series of contract iterations,
especially reviewing and finalizing the appendix to the contract that defines the scope of
services. The final version of the scope identifies and describes twelve tasks, each one requiring
specific city authorization prior to its commencement. Although we will approve a contract for
all required engineering services, only the first three tasks will be authorized immediately. These
are: funding, surveying, and conceptual design. Until these are completed, we will have
insufficient data to proceed with any of the other tasks or develop an accurate estimate of overall
costs, either for the entire project, or for the rest of the engineering.
BUDGET: Proposed cost for Tasks 1-3 are estimated at approximately $370,000.
RECOMMENDATION: Approve attached agreement for professional services and authorize
the mayor to execute.
APPENDIX A — PHASE 1 SCOPE OF SERVICES
General
Generally, the Scope of Services includes professional services necessary for the evaluation of
improvements to the City of Paris Wastewater Treatment Plant (WWTP).
The planned capital improvements include modification and refurbishment of existing facilities as well as
construction of new facilities to meet the targeted capacity and treatment criteria for the existing WWTP.
The evaluation will generally include the following items:
Evaluate rehabilitation of the existing plant to 7.25 MGD:
• Hydraulic capacity of the WWTP Annual Average Design of 7.25 MGD.
• Potential phasing of the capacity of the facility less than 7.25 MGD.
• Planning for identified future regulations as related to future phosphorus removal.
• New influent pump station.
• New headworks facility with fine screening and grit removal with screenings and grit
processing with loading.
• New primary clarifier flow splitter structure.
• New primary clarifiers.
• New secondary treatment splitter structures.
• New conventional activated sludge basins.
• New secondary clarifiers.
• Rehabilitation or repurposing of the chlorine system.
• New RAS/WAS pump station.
• Utilization of structures for new aerobic digesters.
• Rehabilitation and expansion of solids thickening facilities.
• Rehabilitation and expansion of solids dewatering facilities.
• New electrical service facilities.
• New plant water system.
• New backup power generator system.
• New SCADA system.
1. Funding Assistance
Garver will assist the City with pursuit of funding through one funding source, the Texas Water
Development Board (TWDB). Garver cannot guarantee that funding for this project will be available
or that the City will be successful in qualifying for such. Garver will perform the following tasks:
• Coordinate with the Texas Water Development Board via telephone to discuss funding
options available for the project.
• Review the Cities Intended Use Plan for submittal and comment.
• Complete the Project Information Form (PIF) to TWDB funding through the Clean Water
State Revolving Fund (CWSRF) program. When requested, the City will be responsible for
providing necessary data to Garver to complete the form.
• Upon acceptance of the PIF, Garver will assist the City with completing the CWSRF loan
application.
• Draft resolution, if required.
• Attend one pre -application meeting with the City at the TWDB headquarters in Austin, Texas.
• Includes one meeting to present options to council, if required.
Appendix A - Scope of Services 1 of 5
City of Paris WWTP Improvements
2. Conceptual Design Report
The conceptual design phase submittal will include a Conceptual Design Report and a conceptual phase
opinion of probable construction cost. This conceptual submittal will be for the purpose of coordinating
the proposed improvements with the City, the Texas Commission of Environmental Quality (TCEQ) and
the Texas Water Development Board (TWDB) and to develop an order of magnitude cost estimate for the
project. Major elements of the Engineering Report will include the following facility or process evaluations:
• All elements as listed in the "General' section of this Scope of Services.
• Conceptual design report will include likely future limits (based on discussions with TCEQ) for
phosphorus/nitrogen as well as identification of current or future process improvements
necessary to meet these likely future limits.
• Hydraulic Grade Line (HGL) determination throughout the treatment processes from the
WWTP influent to the WWTP outfall.
• Evaluate solids handling operation and propose options for a new solids treatment train
utilizing existing infrastructure where possible.
• Evaluate the benefits of maintaining any existing pump stations for future use.
• Design of a new Activated Sludge System.
- Develop a layout for a new fine bubble diffused air secondary treatment train using
conventional activated sludge.
- Evaluate nutrient removal requirements in future TPDES permit.
- Evaluate improved primary treatment to offset additional aeration basin capacity.
• New RAS/WAS pump station capacity evaluation.
- Evaluate potential for a new RAS/WAS pump station.
• New Aeration Capacity Evaluation.
- Consider the use of existing tankage for future aeration capacity.
• New Digestion Evaluation.
- Consider the use of existing tankage for renovation to new digesters.
• New Backup Power Generator System for critical processes.
• Evaluate SCADA system and determine necessary improvements.
2.1. Historical Data Review
Garver will collect and review relevant information including:
• As -built drawings of each facility
• Previous applicable studies and reports
• Process data and daily monitoring reports for a three year period
• Equipment maintenance records and Operations and Maintenance (O&M) manuals
• Develop sampling plan
2.2. Flow Projections/Load Projections
This sub task will evaluate existing flow rates and compare to existing sewer service population within the
City. The flow rates will then be compared to a 20 year population projection for a complete 20 -year
planning horizon flow projection, as required by TWDB.
The existing wastewater will be characterized by the City under the direction of Garver. These sample
parameters will be utilized in projecting future loading rates for processes. This is anticipated to include
multiple samples, with the analysis of each sample including BOD, Soluble BOD, COD, Soluble COD,
TSS, NH3, Total Phosphorus, Soluble Phosphorus. The City will conduct all sampling, analysis, and pay
for lab fees if needed.
Garver will deliver a Memorandum documenting the findings of the flow and load projections. Deliverable
will be Adobe PDF documents sent electronically.
Appendix A - Scope of Services 2 of 5
City of Paris WWTP Improvements
2.3. Field Investigation
Garver will evaluate the existing wastewater treatment facilities, including existing liquid process treatment
units and solids handling. This assessment will include multi -discipline engineers (Mechanical, Civil,
Electrical, and Process) completing a visual assessment for condition based items to determine which
processes can be reused for the other processes for the rehabilitation.
2.4. Structural Investigation
Garver will perform a visual structural analysis of the existing concrete structures which will be affected
by this improvements project. This concrete analysis will assess the structural integrity of the existing
concrete structures at the WWTP based on at -grade visual observations and record drawings of the
existing structures. While the structural investigation will focus on the existing aeration basins, other major
concrete structures at the WWTP will also be reviewed.
2.5. Existing System Assessment
Garver will perform a facility compliance check to confirm conformance with TCEQ Chapter 217 rules.
Garver will also identify any flood plain concerns for the site.
2.6. Hydraulic and Process Modeling
Garver will perform hydraulic modeling of the existing facility. Modeling will be done utilizing a static model
and record drawings. A determination of the boundary conditions of the hydraulic model will be developed.
Garver will perform process modeling using GPS -X. A process model of the existing facility will be
developed and calibrated. Two alternatives will be evaluated, based on a conventional activated sludge
facility. The process modeling will also consider future nutrient removal regulations.
2.7. Alternatives Evaluation
Garver will conduct a detailed evaluation of up to two process alternatives. Detailed evaluation will include
development of design parameters (e.g., equipment sizing criteria), assessment of rehabilitation
requirements for integration of each alternative to the existing treatment system, evaluation of hydraulic
impacts, development of 10% level site layouts and evaluation of phasing of the proposed
alternatives. Strengths and limitations of each alternative will be identified and conceptual opinions of
probable construction cost developed for each. Work under this task will consider the requirements for
the various engineering disciplines that will be involved in the design of facilities (i.e., civil, electrical,
instrumentation, mechanical, structural, etc.).
Garver will prepare a conceptual design phase estimate opinion of probable construction costs for the
chosen alternative with the recommended project components based upon information obtained during
the conceptual design phase. For the Conceptual Design, Garver will consider these opinions as
estimates and the expected range of accuracy for this type of estimate is -20% to +30% of the estimated
construction cost.
2.8. Conceptual Workshop
Garver will conduct a Conceptual Workshop with the City to present the results of the alternatives
evaluation and establish the approach and expectations for design of the project. City comments will
be documented and incorporated into the draft Conceptual Design Report.
Appendix A - Scope of Services 3 of 5
City of Paris WWTP Improvements
Deliverables
a. Three (3) bound copies of the draft Conceptual Design Report for review and comment by the
City
b. Three (3) bound copies of the final Conceptual Design Report incorporating draft review
comments
c. PDF file of Engineering report
2.9. External Coordination/Meetings
As part of the Conceptual Design Phase, Garver will:
• Coordinate with TCEQ via telephone on project status and design criteria
3. Surveys and Geotechnical Services
3.1. Topographic Surveys
Garver will provide field survey data for designing the project, and this survey will be tied to the City's
control network.
Gamer will conduct field surveys at the existing WWTP, utilizing radial topography methods, at intervals
and for distances at and/or along the project site as appropriate for modeling the existing ground, including
locations of pertinent features or improvements. Garver will locate buildings and other structures, streets,
drainage features, trees over eight inches in diameter, visible utilities as well as those underground utilities
marked by their owner and/or representatives, and any other pertinent topographic features that may be
present at and/or along the project site. Gamer will establish control points for use during construction.
Deliverables
a. Three (3) copies of the topographical survey which maps 1 -foot contours, utilities and existing
structures, with a digital terrain model. Presented in 11x17 format.
b. DWG and PDF files electronically.
3.2. Geotechnical Coordination
Garver will direct the location of borings necessary for design development to the City. Garver will travel
to the site to select locations for exploratory borings. Garver's Surveyor will stake the specific locations
after checking underground utilities and verifying that the locations are clear from utilities and
acceptable to the City.
Garver will also list the required lab tests needed for each boring. City will be responsible for acquiring
the services of the geotechnical firm separate from this Agreement.
4. Extra Work
The following items are not included under this agreement but will be considered as Extra Work. Extra
Work will be as directed by the City in writing for an additional fee as agreed upon by the City and the
Engineer.
1. Easement coordination or easement documents.
2. SSES, I&I analysis, and/or sewer system survey.
3. Design of improvements off-site.
4. Utility relocation coordination or design.
5. Hydraulics and hydrology for floodway No -Rise Certification and Individual 404 permit.
6. Redesign for the City's convenience or due to changed conditions after previous alternate
direction and/or approval.
7. Submittals or deliverables in addition to those listed herein.
8. Invasive structural evaluation techniques beyond visual observation of existing structures at
Appendix A - Scope of Services 4 of 5
City of Paris WWTP Improvements
grade and existing record drawings.
9. Preparation of a Storm Water Pollution Prevention Plan (SWPPP).
10. Construction materials testing.
11. Environmental Handling and Documentation beyond those previously identified, including
wetlands identification or mitigation plans or other work related to environmentally or
historically (culturally) significant items.
12. Floodplain delineation and coordination with FEMA and preparation/submittal of a CLOMR
and/or LOMR.
13. Environmental Services beyond preparation and submission of an Environmental Information
Document.
14. Sludge Management Plan
15. Warranty Assistance
16. Water Reuse Master Plan
17. Utility rate study
18. TMDL and NPDES permitting assistance
19. Water Conservation Plan
20. Drought Management Plan
21. Extra Meetings
22. Jar Testing Services
23. Sampling Services
24. Additional meetings
Extra Work will be as directed by the City in writing for an additional fee as agreed upon by the City and
Garver.
5. Schedule
This schedule is not only contingent on City review and authorization to proceed for each Task, but also
regulatory and funding agencies review and response time.
Appendix A - Scope of Services 5 of 5
City of Paris WWTP Improvements