§ 40-210. Sanitary sewer facilities design criteria.

(a)

Minimum size. No public sewer line shall be less than six inches to the inside diameter.

(b)

Manholes. The developer shall install manholes at all intersections of other sewers six inches in diameter or larger and at intermediate spacings along the line. The maximum spacing shall be in accordance with TCEQ "Sewage System Design Criteria." The developer shall install manholes at all changes in grade and at the ends of all sewers.

(c)

Alignment. The developer shall design sewers with straight alignment. If horizontal curvatures must be used, the smallest radius shall not exceed that recommended by the pipe manufacturer; provided, however, that any radius shall not be less than 100 feet.

(d)

Hydraulic slopes. The developer shall design all sewers with hydraulic slopes sufficient to give mean velocities, when flowing full or half full, of not less than two feet per second on Kutter's or Manning's formulas using a minimum "n" value of 0.013.

(e)

Surface water and nondomestic waste. The developer shall make no connection to any sanitary sewer system that permits the entrance of surface water or waste of other than domestic sewage characteristics without the specific authorization by the city.

(f)

Backfill. The developer shall install and backfill all lines, including all service laterals, below proposed paved areas to city specifications prior to compaction of subgrade and placement of the paving.

(g)

Lift stations. The developer shall not design or construct lift stations or separate treatment facilities unless such lift stations or separate facilities are more beneficial to the city than constructing an adequate outfall or approach sewer from the existing system. In determining benefit, the city shall consider power cost for operation, land costs and all other costs of lift stations based on a ten-year life.

(h)

Alternative sewage treatment facilities. Alternative sanitary sewage treatment facilities shall consist of individual on-site sewage treatment systems or a common collection and treatment system providing service to each lot not owned by the city. If the developer proposes a separate sanitary sewage treatment system, the TCEQ shall approve the plans and permit for such system prior to the final plat approval by the city. Nothing in this section shall be construed as permission to install on-site sewage treatment systems (including septic tanks) without proper permits.

(1)

Variance required. A variance from the requirement to provide a city owned sewage system may be granted by the city at the time of preliminary plat approval if it is determined that the city owned sewage system cannot be technically made available to the area of development (see section 40-19). The developer shall provide the city with sufficient technical data (topography, soils, existing sewer system and construction costs) to demonstrate the proposed development's need for an alternative to the city owned sanitary sewage treatment facilities. In determining the ability of the developer to connect to the city's system, lot size shall not be considered. The developer shall not design or construct such alternative sewage treatment systems unless such facilities are more beneficial to the city than constructing an adequate system extended from and connected to the existing city system.

(2)

Approval by TCEQ. The city shall not approve a final plat until the developer submits an engineered sewage disposal plan approved by the State of Texas.

(Ord. No. O-42-07, § I, 9-24-2007)