SECTION 2

WATER AND WASTEWATER DESIGN CRITERIA

 

TABLE OF CONTENTS

 

Section 

Number

 

2.1.0    GENERAL 

 

2.2.0    SERVICE EXTENSION PROCEDURES

2.3.0    PRIVATE PLUMBING

2.4.0    STANDARD PRODUCTS LIST PROCEDURES

2.5.0    CONSTRUCTION PLAN INFORMATION AND SUBMITTAL REQUIREMENTS

2.6.0    CONSTRUCTION INSPECTION AND ACCEPTANCE

2.7.0    LIFT STATION REVIEW, APPROVAL AND ACCEPTANCE

2.8.0    ABANDONMENT OF FACILITIES

2.9.0    DESIGN REQUIREMENTS FOR WATER AND WASTEWATER SYSTEMS

 

 

 

SECTION 2 - WATER AND WASTEWATER DESIGN CRITERIA

2.1.0     GENERAL

The following information is intended to assist engineers and the general public in the design and construction of water and wastewater facilities. Information herein is to provide minimum New Braunfels Utilities (NBU) requirements only. Sound engineering judgment shall be utilized to determine if these minimum requirements are suitable for each engineering design.

2.2.0   SERVICE EXTENSION PROCEDURE

2.2.1   General Information

This section is intended to provide information needed to obtain water and wastewater service extension approvals for future development. 

 

The service extension is not to be interpreted as a vehicle solely for the purpose of securing a utility commitment, but rather a procurement of rights to install utility mains, associated facilities, and off-site improvements within NBU’s Adopted Water and Wastewater Service Area.  These water and wastewater facilities are not extended through capital improvement programs or other NBU initiated projects.

 

The NBU Service Area is the Impact Fee Boundary for the NBU water and wastewater utility.  It is a set of geographic boundaries within which water or wastewater service may be provided.  Properties must be completely within the service area before a service extension application can be submitted.

2.2.2   Service Extension Application Requirements

The forms listed below are utilized when requesting a service extension. Other forms may apply. Examples of the forms are provided in Appendix A.

 

A.         Administrative Application

B.        NBU Board Application

C.        Service Extension Policy General Provisions

D.        LUE Calculation Sheet

E.        Annexation Request

2.2.3.  Service Extension Guidelines for Processing

A.    All properties not within city limits of New Braunfels must request annexation or give the city the future right of annexation without protest. An annexation request or consent for annexation shall be submitted with the service extension application.

B.    All extension requests not requiring NBU cost participation or reimbursement may be approved by the Chief Engineer of Water Services.

C.    All service extensions requesting NBU cost participation or reimbursement must be submitted to the Chief Engineer of Water Services for consideration and approval by NBU Chief Executive Officer.

D.    Approved applications are not a reservation of capacity in the system, but are an acknowledgment of the intent to serve.

2.2.4.   System Capacity Determination Procedure for Reviewing Service Extensions by NBU

A.    NBU will determine what existing facilities are in place and any remaining capacity after considering all existing services connected and capacities committed to the system.

B.    NBU will determine the length of time, after all funded projects have been constructed, from present conditions until additional system improvements are needed.

C.    A service extension may or may not be approved depending on the time frame of approval, funding, and construction of additional system improvements and related agreements and conditions.

2.2.5.  Expiration of Service Extension Approvals

A.    Expired service extensions may be refiled upon expiration date, not prior.

B.    A new application packet will be required upon refiling.

C.    A new number will be assigned and new fees required.

D.    In cases where approvals are contingent upon developer contracts and/or C.I.P.s, the timing for expiration begins upon completion and NBU acceptance of those projects, not the approval date of application.

 

Note: See Service Extension Policy General Provision in Appendix A for complete guidelines and policy concerning service extensions.

2.3.0.   PRIVATE PLUMBING

2.3.1.  Plumbing Inspections Outside the City’s Zoning Jurisdiction

Within the zoning jurisdiction of the City of New Braunfels and within the boundaries of other jurisdictions as specified by contract, private plumbing installations shall be inspected by the Building Inspection Department to ensure compliance with the requirements of the Uniform Plumbing Code as codified by the City of New Braunfels or other jurisdictions.  New private plumbing installations on properties located outside of the zoning jurisdiction of the City for which NBU provides direct retail water or wastewater service (outside-city installations) shall be inspected in accordance with the following rules:

A.    Service Inspection Verification Form

Work on outside-city installations shall not commence until a Service Inspection Verification Form (SIV) has been obtained from the NBU New Services Division located at 263 E. Main Plaza and any applicable fee has been paid.  For new installations the SIV must be obtained at the time a water and/or wastewater tap is purchased.  A valid SIV must be posted at the site of every outside-city installation.  Each address shall be posted and visible from two hundred (200) feet.

B.    Inspections

Outside-city installations must be inspected for compliance with the Plumbing Code by a third-party inspector (i.e., not employed by the City or NBU) who is registered with NBU.  Registration requirements are set forth below in Section 2.3.1.D.  It shall be the responsibility of the property owner or a representative of the property owner to retain the services of a registered inspector.  A list of registered inspectors may be obtained from NBU New Services Division.

 

The inspector must complete and deliver a Service Inspection Certification Form (see Appendix C) to the NBU New Services Division, certifying that the plumbing installation is in compliance with the Plumbing Code before final connection to the NBU water and/or wastewater systems may be made.

 

Upon the request of NBU, access to plumbing installations must be provided to NBU quality control inspectors.

C.    Exceptions

Repairs, replacement, or alteration of any existing residential plumbing system outside of the zoning jurisdiction of NBU on properties for which NBU provides direct retail water or wastewater service are exempt from the requirements of this section if the work is performed in accordance with the requirements of the Plumbing Code.  Not withstanding the above, verification of compliance with the Plumbing Code and cross connection control shall be at the option of NBU.

D.    Inspector Registration Requirements

Applicants for registration must meet the following qualifications:

 

1.   Applicants must be plumbing inspectors licensed by the Texas State Board of Plumbing Examiners. 

2.   Provide verification of at least one of the following:

a.   Plumbing inspector certification from the International Conference of Building Officials.

b.   Master plumbers license from the State of Texas.

c.   Texas Real Estate Inspector’s License from the State of Texas Real Estate Commission.

d.   Plumbing engineering certification from the American Society of Plumbing Engineers.

3.   Attend the inspection workshop administered by NBU.

4.   Third-party inspectors conducting inspections within the NBU service area shall not have any financial or advisory interest in any plumbing company or plumbing materials or apparatus supply company.

2.3.2.  Adherence to State Rules and Regulations Relating to Backflow and Cross Connection Control

Backflow prevention assemblies installed in private plumbing systems, fire protection systems, process water systems, and/or other private water distribution systems that are directly or indirectly connected to NBU’s potable water distribution system shall obtain laboratory and field testing approval and listing as backflow prevention devices and assemblies from the University of Southern California Foundation for Cross Connection Control and Hydraulic Research (USC FCCC&HR) or other approved agency with field and laboratory testing to American Water Works Association (AWWA) standards and shall be installed in accordance with American Water Works Association manual M-14.  It shall be the responsibility of the property owner or the representative of the property owner to provide verification of the required approvals upon request. The installation, maintenance, repair, replacement and operational testing shall strictly conform to the requirements of AWWA’s of the AWWA’s Cross Connection Control guidelines.

2.4.0    STANDARD PRODUCTS LIST PROCEDURES

2.4.1   Introduction

Through previous investigation, testing and usage by NBU, certain types, brands and models of some products and materials have established a satisfactory record for certain services. These products have been tabulated by manufacturer’s names and identifying numbers on Standard Products Lists (SPL). Construction-related SPL has been assembled into the NBU “Standard Products List”. The Standard Products List should not be interpreted as being pre-approved lists of products necessarily meeting the requirements for a given construction project and products included in the lists shall not be substituted unless they are approved by the Engineer and NBU. Contractors electing to use products from the SPL shall submit a list of products and the corresponding SPL number, together with the approvals for their use.

 

Products in use by NBU are subject to ongoing consideration and evaluation by staff.  When changes, deletions, or additions become necessary and are approved, the product list will be revised and included in updates to the Standard Products List.

 

Questions concerning NBU’s Standard Products List may be addressed to the Material Management Division.

2.4.2   NBU Water and Wastewater Utility Standard Product Approval Process

A.   Product and equipment manufacturers shall submit a written request for consideration to the Material Management Division.  This request shall comprise a complete submittal, in a single package, and include the following:

1.   Product description, technical specifications, and catalog information.

2.   All applicable product standards (AWWA, ASTM, ANSI, NFPA and others) and related manufacturer’s certifications.

3.   Test results showing compliance with applicable standards, including independent laboratory test results, if necessary.

4.   Manufacturer’s installation procedures for the particular product.

5.   Product availability, delivery time, and manufacturer’s location.

6.   Maintenance requirements, special equipment and procedures, and recommended maintenance schedules.

7.   Product references (municipal or public users) shall include users name, address and telephone number, product application and number of years in use, and name and telephone number of a contact person having knowledge of the particular usage.

8.   Material safety data sheet (MSDS), if applicable.

9.   Recent product revisions or improvements.

10.   Explanation of how the product benefits NBU in terms of prolonged service life, reduced maintenance, reduced life-cycle cost and other relevant aspects.

 

B.   If the submittal is acceptable, the Material Management Division shall submit it to NBU staff for consideration. Products may be requested for testing or field evaluation.

C.  Following review of the submittals NBU staff may request a presentation by the manufacturer at a regularly-scheduled staff meeting to demonstrate the product or provide additional information.

D.  Procedures for testing or evaluation shall be as agreed upon between the supplier and NBU. Results will become a part of the product file and will be made available to the supplier upon request.

E.   When products are evaluated in a construction or CIP project, the location and installation details shall be recorded in the inspection record and filed with NBU.  In addition, the installation shall be cross-referenced on all as-built plans, profiles, quad maps, and other NBU maintained maps.

F.   A database listing all testing locations, time of test and results shall be compiled and periodically updated. From this information, the NBU staff will recommend approval or disapproval of the products.

G.  Material Management Division will advise the applicant of NBU’s decision regarding the product.

H.   The newly accepted product will be added to the appropriate Standard Products List (SPL).

I.    Problems regarding accepted products shall be submitted to Material Management Division for review. Such review may lead to a recommendation to rescind approval. NBU shall inform the product manufacturer of the reasons for removal from the SPL.

2.4.3   Product and Purchase Specification Review

All purchase specifications and each SPL will be reviewed at least every five (5) years. Products will be under constant evaluation as they are used in the water and wastewater systems.

2.5.0    CONSTRUCTION PLAN INFORMATION AND SUBMITTAL REQUIREMENTS

2.5.1   General

A.   Construction plans for water and/or wastewater service shall be submitted to the Water Systems Engineering Division for verification of conformance to the NBU Standards and Specifications.

B.   Plans submitted to NBU must show approved easements and/or permits on highway and/or railroad crossings.

C.  A Development Permit must be obtained from the regulatory agencies prior to final plan approval.

D.  Plans that include fire lines must have approval by the City of New Braunfels Fire Department and other related agencies.

E.   All water and/or wastewater plans will include the following items:

1.   Engineer’s dated signature and seal of a Professional Engineer licensed in the State of Texas on each plan sheet.

2.   Date of plans and revisions.

3.   North arrow and scale must be shown.  The standard horizontal scale for plan and profile sheets shall be 1” = 50’, 40’ or 20’ for the plan view. The vertical scale shall be 1” = 5’, 4’ or 2’.  The same scale shall be used on all plan and profile sheets. For sheets other than plan and profile, horizontal scales of 1" = 50', 40' or 20' may be used as appropriate.

4.   A general location map.

5.   Standard NBU Water and Wastewater construction notes.

6.   Indicate on cover sheet, subdivision file number and/or service extension number and all required permit numbers such as development permit, Texas Department of Transportation permit, railroad crossing permit, etc.

7.   Volume and page number of recorded easement and of any temporary working space.

8.   Size, pipe material and location of main with respect to the easements and rights-of-way.

9.   Property lines and dimensions, legal description, lot and block numbers, rights-of-way dimensions, and curb and sidewalk locations and street names.

10. Location, size, and material of all existing water and wastewater mains, lines, and services.  The direction of flow in the wastewater mains shall be indicated.

11. Location, size, and description of other utilities where they may conflict with water or wastewater mains or other service lines.

12. Curve data for roads, property lines, and water and wastewater lines.

13. Final plat recording or land status report.

14. Street address for all existing structures shall be shown on the lot(s) where the structures are located.

15. Pressure zone designation for subject tract and zone boundaries where applicable.

C.  Final plan approval may require additional authorizations.

1.   Texas Department of Transportation permit

2.   Railroad permit

3.   Gas Company permit

4.   Easement acquisition (Volume and Page listed on plans)

5.   County approval

6.   Texas Department of Health approval

7.   Texas Commission on Environmental Quality approval

8.   Non-occupancy letter

9.   Service Extension approval

2.5.2   Water System Plan

A.   All plan view drawings shall include all applicable items listed in the General Requirements above plus the following items.

1.   Stations of all proposed connections to existing or proposed water mains.

2.   For proposed connections to water mains or facilities to be constructed by others: identify the project by name, the design engineer, and service extension number.

3.   Station numbers for mains shall be identified for beginning points, ending points, points of curvature, points of tangent, points of reverse curve, points of intersection, valves, fire hydrants, other appurtenances and grade breaks.

4.   Station numbers shall be identified for the water mains where they cross any other utility.

5.   Details of appurtenances shall be shown.

6.   The location of all existing and proposed water services, water mains, valves and fire hydrants shall be identified.

7.   One hundred year flood plain limits shall be shown.

8.   A reference noting the field book notes for the original survey.

9.      Design velocity at maximum day plus fire flow.

10.  Calculated design pressure at highest and lowest lot served.

11. Thrust restraint when required shall be shown on the plan view.

12.  Retaining walls, including geogrid, straps, tie-backs and all other components.

13.  Culverts, bridges, and other drainage structures.

B.     All profile view shall be provided for all water mains 12 inches in diameter and larger.  It shall show all applicable items listed in the General Requirements plus the following items:

1.   The existing ground profile and proposed street finish grade or subgrade.

2.   Station numbers and elevations of all utility crossings.

3.   Station numbers and soil geology information at stream crossings to evaluate the need for special surface restoration.

4.   Identify pipe size, percent grade, and pipe material to be used including ASTM and/or AWWA designation. If an alternate material is to be allowed, both should be listed (example “D.I. or DR14 PVC”).

5.      Station numbers and elevations for starting points, ending points, point of intersection, grade breaks, valves, fire hydrants, air release valves, pressure/flow regulating valves and at intermediate points every 100 feet.

6.      Retaining walls, including geogrid, straps, tie-backs and all other components.

7.      Culverts, bridges, and other drainage structures.

2.5.3   Wastewater System Plans

A.   All plan view drawings shall include all applicable items listed in the General Requirements mentioned above plus the following items.

1.   Station numbers at all proposed connections to existing or proposed wastewater mains.

2.   For proposed connections to wastewater mains or facilities to be constructed by others, identify the project name, the design engineer, and the service extension number.

3.   The location, alignment, and structural features of the wastewater main, including manholes and concrete retards, if applicable.

4.   Station numbers for beginning points, ending points, manholes, clean-outs and other appurtenances.

5.   Details of all required appurtenances.

6.   Location of all existing and proposed wastewater services, mains and manholes.

7.   One hundred year flood plain limits.

8.   A reference noting the field book notes for the original survey.

9.   Retaining walls, including geogrid, straps, tie-backs and all other components.

10. Culverts, bridges, and other drainage structures.

B.     A profile view shall be provided for all wastewater mains and shall include all applicable items listed in the general requirements above plus the following items:

1.   The existing ground profile and proposed street finish grade or subgrade or finished grade if not under pavement.

2.   Station numbers and elevations of all utility crossings.

3.   Station numbers and soil geology information at stream crossings to evaluate the need for special surface restoration.

4.   Identify the pipe size, percent grade, and pipe material to be used including ASTM and/or AWWA designation.  If an alternate material is to be allowed, both should be listed (example “DI or PVC”).

5.   Station numbers and elevations for starting points, ending points, manholes, clean-outs, and at intermediate points every 100 feet.

6.   Elevations shall be indicated on the profile showing the finish floor elevations of all existing structures.  If the structure has an active septic tank or other disposal system, the flow line elevation of the plumbing where it exits from the structure is to be indicated.  If a lot or tract is vacant, side shots may be required from the middle of each lot to ensure gravity service is possible from the lot to the main.

7.   Design flows, minimum and maximum, and flow velocities at minimum and maximum dry weather flows.

8.      Retaining walls, including geogrid, straps, tie-backs and all other components.

9.      Culverts, bridges, and other drainage structures.

 

(NOTE: Plan Approval shall expire three years from the date of current approval.  If construction has not begun on the facility within three years of the approval date, plans must be resubmitted for approval and must include all criteria in effect at the time resubmitted.)

2.6.0      CONSTRUCTION INSPECTION AND ACCEPTANCE

2.6.1    Construction Inspection Procedure

To have a NBU inspector assigned to a project, the following items must be submitted to the Water Systems Engineering Division.  The appropriate contact person will be able to answer any questions regarding the following information:

A.   Two (2) sets of signed plans are required.  Also required are two (2) copies of signed contracts (lump sum contracts should include water and wastewater quantities on a developer’s or consulting engineer’s letterhead), two (2) sets of cut sheets with one (1) copy of field notes and two (2) copies of any permits listed on the front of the plans.  The engineering review and inspection fees, if applicable, will be determined at that time and payment must be made prior to beginning of construction.

B.   One (1) copy of the bid tabulation (if the project is bid out) will be required with the above listed items for all service extensions submitted for construction.  All of these required items must be submitted at the same time.  For reviews occurring during the construction phase, two (2) copies of the revised plans are required.

C.  To set up a Pre-Construction Conference, contact the Water Systems Engineering Division.

D.  One (1) copy of the signed plans and contracts must be submitted to the appropriate office at least three (3) working days before the Pre-Construction Conference.  It shall include the name and phone number of the contact person listed above.

E.   The contractor shall call the One Call Center for information on existing buried utilities.

 

(Note:  All buried utilities are not included in the One Call System.  The contractor shall call the Water Services Engineering Division for water/sewer locations.)

2.6.2    NBU Acceptance

To obtain final NBU acceptance of a project, paper and digital copy of record drawings showing all field changes, final quantities and cost information, along with the consulting engineer’s concurrence for acceptance form, must be submitted. Any outstanding fees, based on final cost figures, must be paid prior to final acceptance.

If landscaping and vegetation items are outstanding, a conditional acceptance letter may be issued.  This allows for the release of letter of credit requirement for the majority of the water and wastewater related work that has been satisfactorily completed. When all work is completed and all necessary information is provided, a final acceptance letter will be issued.

If the project includes a lift station, the lift station will be considered separately for operation and maintenance acceptance.  (Refer to Section 2.7.3)

2.7.0      LIFT STATION REVIEW, APPROVAL AND ACCEPTANCE

2.7.1    Engineering Report, Plans and Specifications Review and Approval

(NOTE:  Plan Approval shall expire three years from the date of approval.  If construction has not begun on the facility within one year of the approval date, plans must be resubmitted for approval and must include all criteria in effect at the time resubmitted.)

 

A.   Prior to design two (2) copies of a detailed engineering report shall be submitted to the Water Systems Engineering Division for review and approval of the lift station and all related line work.  The engineering report shall include the following:

1.      Justification for the proposed lift station.  The report must clearly show that gravity lines are not available and are not economically feasible and that the number of lift stations has been minimized. This justification must include a cost benefit analysis of gravity versus lift station project including 30 years of operation and maintenance of the proposed system.

2.      A master development plan for the service area of the proposed lift station shall be prepared.  This plan shall include a map showing the location of the lift station, the service area, the boundaries of the drainage basin it is in and the location of the nearest existing wastewater interceptor within that basin.

3.      Engineering calculations and data described in Sections 2.9.3.A and 2.9.3.H shall be contained in the engineering report.

4.      The Engineering Report shall be approved by NBU prior to beginning preparation of the plans and specifications.

B.   Prior to construction two (2) complete sets of the plans and specifications shall be submitted to the Water Systems Engineering Division for review and approval. These plans and specifications shall be prepared, sealed, signed, and dated by a Professional Engineer licensed to practice in Texas and shall be in compliance with the approved Engineering Report. The plans and specifications for the lift station shall also include all related line work and a comprehensive site plan including any required access road(s) and easement(s).

 

C.  All plans and specifications for lift stations within the NBU Service Area, submitted for review and approval, must demonstrate compliance with current NBU Design Criteria and standard lift station specifications.  Approval of the lift station plans and specification does not imply NBU will accept the lift station for operation and maintenance (Refer to 2.7.3).

 

1.   Within the NBU Service Area the following type of Lift Stations may be submitted for review and approval:

a.   Self priming pump facilities with rated horsepower no greater than 25 BHP for the largest pump.

b.   For installation with a required rated horsepower motor greater than 25 BHP the Utility prefers wet/dry well type installation.  However, self priming pump facilities with a rated horsepower of between 25 BHP and 50 BHP may be considered on a case-by-case basis. The Engineer must submit cost comparisons for self priming versus wet/dry well installations. The cost comparison should include initial station costs, pump replacement costs, installation costs, and all operational and maintenance cost including energy costs over the life of the station. The comparison should assume a typical service life for pumps.

 

2.7.2    Submittal and Shop Drawing Review

Once the engineering report, plans and specifications have been approved, at least two (2) complete sets of submittals and shop drawings shall be provided to the NBU Water Systems Engineering Division.  These submittals shall contain complete detailed information and drawings for all lift station equipment and components.

2.7.3    NBU Operation and Maintenance Acceptance

NBU may accept a lift station with a firm pumping capacity greater than 120 gpm for operation and maintenance provided the following conditions are met:

A.   The station is located within NBU’s approved wastewater service area.

B.   NBU has inspected the lift station and determined that it is constructed in conformance to NBU’s requirements.  Any lift station not conforming to Utility standards shall be upgraded to NBU standards before NBU will accept the lift stations for operation and maintenance.

C.  The owner or his representative has provided all information requested in Sections 2.7.1 and 2.7.2 above, five (5) complete sets of all Operations and Maintenance Manuals for all equipment installed, and has received NBU’s approval.

D.  The owner has granted NBU a wastewater easement for the lift station and access road.  A copy of the recorded easement plat, legal description and any other legal documents granting the easement shall be delivered to NBU.  The easement shall extend to at least five (5) feet outside the lift station fence and shall include access road with turn-around areas that extend back to paved public rights-of-way. This easement shall be separate and in addition to any necessary pipeline easement.

If the lift station is to become a permanent installation, transfer of ownership and title to the land may be required by NBU prior to acceptance of the station for operation and maintenance.

E.   A letter of assignment has been written to NBU from the owner transferring title of the lift station and related equipment to NBU.  This letter shall be delivered to NBU before acceptance of the lift station for operation and maintenance.  The original owner may regain title to a temporary lift station that was designed and constructed entirely at his expense and for which no refund was made by NBU.  After written notification by NBU that the lift station has been abandoned, the original owner has one (1) month to notify NBU in writing of his intent to regain title to the temporary lift station site.

F.   One (1) complete set of reproducible Mylar of the as-built drawings and a copy of the file on disk(s) in electronic format as specified by Water Systems Engineering shall also be provided to NBU prior to acceptance of the lift station for operation and maintenance.

2.8.0      ABANDONMENT OF FACILITIES

              If a new project will abandon existing facilities, the plans shall provide for the appropriate abandonment of these facilities.

2.8.1    Mains

            Abandonment of wastewater mains in private easements shall consist of filling the main with a pumpable grout or slurry and meeting requirements of the current specifications.  Plans should include method of abandoning all other Mains.

2.8.2    Manholes

            The abandoned manholes shall be removed to a level not less than four feet below grade, inlets and outlets securely plugged and the structure filled with stabilized sand in compliance with current specifications shall be required.

2.8.3    Lift Stations

            Abandonment of lift stations shall consist of removing all pumps, motors, couplings, valves, and controls from the dry well and all appurtenances above finished grade.  Both the wet well and dry well shall be cut down five feet below grade, filled with cement stabilized sand, and covered with top soil to grade. The associated force main shall be properly abandoned.  This includes cutting and plugging both ends and/or grouting main as appropriate. 

Area shall be re-vegetated.  NBU shall be notified prior to abandonment.

2.8.4        Service Lines

All water service lines (including fire lines) that are being abandoned and not transferred to a new distribution line should be disconnected at the corporation stop and all other valves and appurtenances removed.

2.9.0      DESIGN REQUIREMENTS FOR WATER AND WASTEWATER SYSTEMS

2.9.1    INTRODUCTION

These guidelines are intended to establish the minimum basic design requirements for water and wastewater systems within NBU’s service area, but do not address major facilities such as water and wastewater treatment plants. Generally, these systems will be operated and maintained by NBU.

All project manuals shall include the appropriate NBU Standard Specifications.  All projects are required to be built in accordance with these NBU Standard Specifications, which may include other requirements not addressed here. All variations are subject to the approval of NBU. Additional requirements for specific projects may be established where the conditions of service to the tract and related system operation and maintenance needs warrant.

The following information is provided to assist engineers and the general public in the design and construction of water and wastewater facilities within the NBU service area.  All plans for such facilities shall be prepared by or under the supervision of a Professional Engineer, licensed in the State of Texas.  It will be the responsibility of the engineer to ensure that the plans are in compliance with the latest versions of all applicable federal, state, and local ordinances, rules, and regulations.

These include, but are not limited to, the following:

A.   Design Criteria for Sewage Systems - Texas Commission on Environmental Quality (TCEQ).

B.   Rules and Regulations for Public Water Systems - TCEQ.

C.  The Code of the City of New Braunfels.

D.  NBU Standard Specifications.

E.   NBU Water and Wastewater Design Criteria.

2.9.2    WATER SYSTEMS

A.   Size/Capacity Determination

1.   General

a.      Hazen Williams Friction Coefficient C = 100, higher C coefficient may be used for new mains only upon approval by NBU with sufficient documentation to show effects of long term use.

b.      Average day demand = 200 gal/person/day

c.      Peak day demand = 530 gal/person/day

d.      Peak hour demand = 900 gal/person/day

e.      Maximum static pressure - 150 psi (fire hydrants will have attached pressure reducing valve (PRV) where pressure exceeds 110 psi)

f.        If the maximum static pressure exceeds 80 psi, a PRV will be required on the property owner’s side of the water meter and should be shown on the plan view.

g.      Minimum operating pressure is 50 psi at the highest elevation meter location using average day demand.

2.   Peak Hour Demand Requirements

a.   The maximum allowable velocity shall not exceed 5 feet per second (fps).

b.  The minimum pressure at any point in the affected pressure zone must not be less than 35 psi.

3.   Emergency Demand (Fire Flow) Requirements

a.  The maximum allowable velocity shall not exceed 10 fps.

b.   Fire flow requirements will be determined in accordance with the City of New Braunfels Fire Code and associated rules.

c.   The minimum residual pressure at any point in the affected pressure zone at peak day plus fire flow must not be less than 20 psi.

4.   Sizing of Water Mains - Computer modeling is preferred for sizing water mains. However, for water mains less than 12 inches in diameter other engineering calculation methods may be accepted. The largest size, as determined by comparing the service area’s peak hour demand and peak day plus fire flow demand, shall be used.

5.   Storage Requirements - If it is determined by NBU that additional storage is required, the following criteria shall be used:

      Effective Storage       =  100 gal/person

      Emergency Storage   =  100 gal/person

      TOTAL STORAGE     =  200 gal/person

 

Effective Storage is defined as storage, which will provide a minimum of 35 psi of pressure at the highest service elevation in pressure zone.

The Engineer may be required to provide computer simulations as determined on a case by case basis.

B.   Mains

1.   Minimum main size shall be 8 inches with consideration for 6-inch pipe in cul-de-sacs less than 400 feet in length.  Provision must be made in these cases for a flush valve at the end of the line.  The minimum size for any street type, however, will be governed by various factors which include fire protection requirements, high density land usage, and the designer’s consideration of general system gridding, future transmission mains, neighboring developments and area configuration. Looped systems are required for service reliability. Transmission line sizes will be determined on a case by case basis.

2.   Water mains should be located, where maintenance can be accomplished with the least interference with traffic, structures, and other utilities.

The separation between water and wastewater mains must comply with TCEQ rules or have a variance approved by TCEQ before submittal to NBU.  [Texas Administrative Code, Title 30, Part 1, Chapter 317, Rule 317.2, paragraph (a) (7)]

Mains should usually be located on the high side of the street.  The location considered as the standard assignments should be halfway between the center of street and the curb line.

In major collector and arterial roadways, mains should be located outside the pavement, curbs, etc., wherever feasible.  When mains are located outside of the rights-of-way, they shall be within a dedicated utility easement.  Main assignments in such city streets must be approved by NBU.  Assignments for lines in county roads must also be approved by the county engineer.

3.      Piping materials and appurtenances shall conform to NBU Standard Specifications and the NBU Standard Products List (SPL).

4.      Minimum depth of cover over the uppermost projection of the pipe and all appurtenances shall comply with NBU Standard Details; maximum depth will be as approved by NBU for the specific materials, application, and conditions.

5.      For mains of 16 inches and larger, drain valves shall be placed at low points.

6.      All fire lines shall have a gate valve on the line at the connection to the main line and a backflow preventer inside the property line, but accessible for inspection by NBU and City personnel.  All unmetered fire lines shall have a NBU approved backflow device.

7.      On water mains 16 inches in diameter and larger, automatic air release valves will be placed at all high points and at the down-slope side of all valve locations.  Air/vacuum and vacuum release valves shall be approved on a case-by-case basis.

8.      No water line shall be deflected either vertically or horizontally, in excess of that recommended by the manufacturer of the pipe or coupling without the appropriate use of bends or offsets.  Fittings may be required where more than two pipe lengths are deflected.

9.      The determination of whether or not a given section of pipeline needs restrained joints or other means of anchorage shall be made by qualified professional engineer and approved by New Braunfels Utilities.  All thrust anchorages shall be designed for a safety factor of not less than 1.50 under maximum pressure loading.  Thrust blocks will not be allowed on the system without special approval.  Joints will be restrained with restraining systems approved by NBU and restraint length shall be submitted to NBU at the time of plan submittal.

C.  Valves

1.  There shall be a valve in each fire hydrant lead restrained to the main.  These, and all valves sixteen (16) inches and smaller, shall be resilient seated gate valves.  In lines larger than sixteen (16) inches and larger, butterfly valves may be used.

2.  Valves shall be located at the intersection of two or more mains and shall