§ 16.28.050. Improvements—Minimum standards.
A.
Generally. The following minimum standards for improvement shall be agreed to in each subdivision subject to this chapter before final approval of a plat by the commission.
B.
Street and Roadway Pavement. All roadways shall be curbed unless specifically exempted by action of the city council.
The minimum pavement section for new streets/roadways shall consist of two inches of hot mix asphaltic concrete material (HMAC) over a specified thickness between eight inches to 12 inches of flexible base material over compacted subgrade or fill material. An asphalt prime coat shall be placed over the base material prior to HMAC installation. The specified thickness of flexible base material is determined by the classification of the roadway.
Below listed is the required thickness of base material according to the street classification.
Street Classification * Required thickness of base material Minor Streets 8" Local Streets 8" Secondary Collector Street 10" Primary Collector Street 12" Marginal Access Streets 12" Major Thoroughfares Texas Department of Transportation
Standards* Street Classifications are defined in section 16.04.020, "Definitions".
Pavement Subgrade: Subgrade areas shall be scarified to a depth of six inches and moisture conditioned between optimum and plus four (+4) percentage points of the optimum moisture content. The moisture conditioned subgrade shall then be compacted to at least 95 percent of maximum dry density determined in accordance with TxDOT Tex-114-E or ASTM D698. The subgrade should be moisture conditioned just prior to fill or base placement so the subgrade maintains its compaction moisture levels and does not dry out. Density and moisture testing shall be performed at least once every 2,500 square feet of subgrade, but no fewer than three tests.
Pavement Flexible Base Course: Flexible base material shall be composed of crushed limestone base meeting all the requirements of 2004 TxDOT Standard Specifications, Item 247, type A, Grade 1 or 2 including triaxial strength. The base shall be compacted to at least 95 percent of the maximum dry density as determined by the modified moisture-density relationship TxDOT Tex-113-E or ASTM D1557 at moisture contents ranging between minus two (-2) and plus three (+3) percentage points of the optimum moisture content. Density and moisture testing shall be performed at least once every 2,500 square feet of base material, but no fewer than three tests.
Prime Coat: All flexible base materials shall be sealed with an asphalt material (prime coat) prior to paving. All asphalts and emulsions used for prime coat shall conform to the requirements of Item 300, "Asphalts, Oils and Emulsions" of the 2004 TxDOT Standard Specifications. The asphaltic material for prime coat shall meet the requirements for Cut-Back-Asphalt, "MC-30" or "MC-250", Emulsified Asphalts, "AE-P", "SS-1", "MS-2", "CSS-1", or other asphalts or emulsions as approved by the city/engineer.
Hot Mix Asphaltic Concrete Surface Course: The asphaltic concrete surface course shall be plant mixed, hot laid Type D (fine graded surface course) meeting the specification requirements of 2004 TxDOT Standard Specifications Item 340. The mix shall be designed for a stability of at least 40 and shall be compacted between 91 and 95 percent of the maximum theoretical density as measured by Tex-227-F. The asphalt cement content by percent of total mixture weight should fall within a tolerance of ±0.3 percent asphalt cement from the specific mix. In addition, the mix should be designed so 75 to 85 percent of the voids in the mineral aggregate (vma) are filled with asphalt cement. The mix shall have at least 70 percent strength retention when tested in accordance with Tex-531-C. Density testing shall be performed at least once every 2,500 square feet of asphalt material, but no fewer than three tests.
The owner/contractor shall provide results of compaction testing from a certified materials testing laboratory. Material proctors of the subgrade and base materials must be obtained prior to initiation of compaction activities. The mix design of the asphaltic material must be submitted to the city for review and approval prior to application.
Materials that do not meet the required standards must be removed and replaced to standard at the expense of the owner/contractor.
QUALIFICATION OF LABORATORY
(A.)
Meet "Recommended Requirements for Independent Laboratory Qualifications", published by American Council of Independent Laboratories.
(B.)
Meet Basic requirements of ASTM E329, "Standards of Recommended Practice for Inspection and Testing Agencies for Concrete and Steel as Used in Construction" and ASTM E548.
Pavement widths, including standard 18-inch curbs and gutters for the various types of streets as follows:
Local 40 feet Secondary Collector 40 feet Primary Collector 40 feet Marginal 30 feet C.
Sidewalks. Sidewalks may be required when the judgment of the planning commission decides that the safety of pedestrians requires such sidewalks.
D.
Alley Pavements. Alley pavements shall be a minimum of twelve (12) feet in width of flexible base six inches thick, and a single course inverted penetration topping.
E.
Sewer Connections. Where a public sanitary sewer is reasonably accessible, each lot within a subdivided area shall be provided with a connection to such sanitary sewer. The minimum size for mains shall be approved by the city manager.
F.
Other Methods of Sewage Disposal—Generally. When any subdivision is planned that is not reasonably accessible to a public sanitary sewer, it shall provide either for the use of septic tanks or an individual sewage treatment plant as provided in subsections G and H of this section.
G.
Septic Tanks. In all subdivisions planned for septic tank use the minimum lot area shall be in compliance with applicable state standards. Septic tanks shall be installed on each lot concurrent with any development thereon and the design of such system and the method of installation shall conform in all respects to the requirements of the city-county health unit of the county. The city-county health unit shall have the authority to vary the lot area requirement where satisfactory evidence is presented indicating that soil conditions are such as to warrant a modification.
H.
Individual Sewage Treatment Plants. In all subdivisions planned to be serviced by an individual sewage treatment plant, lots may be of standard area and sewers shall be installed to serve each lot. The plant providing such sewage disposal facilities shall be constructed in accordance with the regulations and requirements of the State Board of Health and with the approval and under the supervision of the city-county health unit of the county and the city manager.
I.
Water Supply—Where Public Supply Available. Where an approved public water supply is reasonably accessible or procurable, each lot within the subdivided area shall be provided with access to such water supply. The layout shall be designed to form a loop system. No main shall be smaller than six inches and the minimum size for service lines shall be four inches, except that two inch stubs may be extended to serve a maximum of three lots.
J.
Water Supply—Where Public Supply Not Available. In areas where a public water supply is not available, the subdivider shall construct wells in such a manner that an adequate supply of potable water shall be available to every lot in the subdivision. Such water supply system shall be constructed under the supervision of the city-county health unit of the county and shall comply with all regulations of the State Board of Health in regard to such systems, as well as providing the pipe sizes and layout requirements of subsection I of this section.
K.
Larger Mains or Lines for Future Extension. Where it shall be determined by the city manager that larger mains or lines are required in order to provide for the future extension of the utility system beyond the limits of the subdivision in question, the city shall assume the responsibility for any additional cost.
L.
Drainage. Drainage shall be provided by surface construction as approved by the city manager.
M.
Street Lighting. The subdivider shall, at his or her own expense, install street lighting of the type and in the locations prescribed by the city's current street lighting policy which shall be incorporated into and be a part of the minimum standards authorized in Section 16.28.040.
(Ord. No. 2013-20, § 2, 10-22-2013; prior code § 23-100)