(a) An owner shall submit an engineering report within 30 days of the date of the executive director's written request.     
      (b) The engineering report must include the signed and dated seal of the engineer responsible for the engineering report.     
      (c) The engineering report must include all pertinent calculations, analyses, graphs, formulas, constants, tables, geologic information, hydraulic information, hydrological information, historical data, manufacturer's recommendations, technical assumptions, and any other information needed to demonstrate that the design of the project complies with this chapter.     
      (d) If a variance is requested, the engineering report must include a justification for the variance and all pertinent supporting calculations, analyses, graphs, formulas, constants, tables, geologic information, hydraulic information, hydrological information, historical data, manufacturer's recommendations, technical assumptions, and any other information needed to justify the variance request.     
      (e) If the executive director requests additional information for the engineering report, an owner shall submit the requested information prepared, signed, and sealed by an engineer, within 30 days after the date of a written request.     
      (f) The engineering report for a collection system project must include the following:      
        (1) a map showing the current service area, the proposed service area, and any area proposed for future expansion;       
        (2) the topographical features of the current, the proposed, and any future service areas;       
        (3) a description of how the design flow was determined;       
        (4) the minimum and maximum grades for each size and type of pipe;       
        (5) calculations of expected minimum and maximum velocities in the collection system for each size and type of pipe;       
        (6) the proposed project's effect on the existing collection system's capacity;       
        (7) the existing and anticipated inflow and infiltration, the hydraulic effect of the inflow and infiltration on the proposed and existing systems, inflow and infiltration flow rate monitoring, and inflow and infiltration abatement measures;       
        (8) a description of the ability of the existing and proposed trunk and interceptor collection systems and lift stations to handle the peak flow;       
        (9) the capability of the associated wastewater treatment facility to receive and treat the anticipated peak flow;       
        (10) an engineering analysis demonstrating compliance with structural design, minimization of odor-causing conditions, and pipe design requirements of this chapter;       
        (11) a description of the areas not initially served by the project, and the projected means of providing service to these areas, including special provisions incorporated into the present plans for future expansion;       
        (12) the calculations and pump curves showing the operating characteristics of all collection system lift stations at minimum, maximum, and design flows during both present and future conditions; and       
        (13) the safety considerations incorporated into a project design, including ventilation, entrances, working areas, explosion prevention, and methods for rerouting a portion of the collection system during repair work.       
      (g) The engineering report for a wastewater treatment facility project must include the quantity and characteristics of the influent, wastewater treatment facility siting information, a sludge management plan, methods to control bypassing, calculations and supporting information.      
        (1) Influent Characteristics. The engineering report must include quantity and characteristics of any existing wastewater influent, any proposed changes to the influent quantity and characteristics, and any anticipated changes to the influent quantity and characteristics. If adequate records are not available, analyses must be made of the existing conditions, and the results included in the engineering report.       
        (2) Wastewater Treatment Facility Siting Information. The engineering report must include:                  (A) a general location map for the proposed wastewater treatment facility;                   (B) a description of the area surrounding the wastewater treatment facility that includes prevailing winds, water treatment facilities, water supply wells, surface water intakes, housing developments, industrial sites, highways, streets, parks, schools, recreational areas, shopping centers, and any other information required by the executive director;                   (C) a map of the wastewater treatment facility site, including the site boundary, buffer zones, and the 100-year floodplain, with supporting documentation of compliance with the buffer zone criteria and the 100-year floodplain restrictions specified in §309.13 of this title (relating to Unsuitable Site Characteristics) that is clearly legible; and                   (D) a map of the discharge route or land application unit that is clearly legible.         
        (3) Sludge Management Plan. The engineering report must include a sludge management plan that provides information regarding:                  (A) the estimated quantity and quality of sludge that will be generated, including future sludge loads based on flow projections;                   (B) the sludge treatment requirements for final disposal, and the sludge storage requirements for each alternative;                   (C) a method of sludge transport, use, storage, and disposal; and                   (D) the alternatives, contingencies, and mitigation plans that ensure reliable capacity and operational flexibility.         
        (4) Methods to Control Bypassing. The engineering report must include:                  (A) information and data describing features to prevent bypassing such as auxiliary power, standby and duplicate units, holding tanks, stormwater clarifiers, or flow equalization basins; and                   (B) operational arrangements such as the ability of pipes and valves to control flow through the treatment units and reliability of power sources to prevent unauthorized discharges of untreated or partially treated wastewater.         
        (5) Calculations and Supporting Information. The engineering report must include:                  (A) the types of units proposed and their capacities;                   (B) the detention times, surface loadings, and weir loadings pertinent to each wastewater treatment unit;                   (C) a plot of the hydraulic gradient at peak flow conditions for all gravity lines;                   (D) the anticipated operation mode of the wastewater treatment facility;                   (E) organic and volumetric loadings pertinent to each treatment unit; and                   (F) aeration demands and how those demands will be supplied.         
     Source Note:        The provisions of this §217.10 adopted to be effective August 28, 2008, 33 TexReg 6843; amended to be effective December 4, 2015, 40 TexReg 8254