Section 18 AAC 72.515 - Conventional wastewater systems requiring plan approval(a) Before constructing, installing, or modifying any part of a conventional wastewater system, a person must have prior department approval in accordance with 18 AAC 72.200 if (1) the system has a design flow greater than 2,500 gallons per day;(2) a single lot or facility has more than one wastewater system and the cumulative I on-lot or facility-wide design flow is greater than 2,500 gallons per day;(3) the system serves more than one lot or building not under the same ownership;(4) the system receives non-domestic wastewater; or(5) the system does not otherwise qualify for the exception under 18 AAC 72.511.(b) In order for a submittal requesting department approval to be considered complete, in addition to the general items required for submittal under 18 AAC 72.205, an applicant must include (1) a cover letter, engineer's report, and calculations, sealed by a registered engineer, that fully describe the project and type of facility and adequately demonstrate that the design meets the applicable approval criteria in this chapter, including (A) design flow calculations with the basis used for calculation;(B) waste loads and waste strength with the basis for calculation if the system is serving a facility other than a residential dwelling;(C) information and calculations regarding the septic tank size and tank design, including access openings and security;(D) methods of septic tank pumping and location of septage disposal;(E) information and calculations regarding the sizing and design of the soil absorption system;(F) information and calculations regarding private and community sewer lines slopes, conduit velocity, materials, and other relevant details;(G) information and calculations regarding pumping station design, pump selection, system curves, pressurized sewer lines, and other relevant details;(H) thermal protection including potential seasonal use considerations;(I) siting of the system with respect to potential hazards such as slopes and cut banks;(J) siting of the system with respect to private and public water systems, groundwater, and surface water, and information on how the system is protective of public health, drinking water sources and systems, surface water and groundwater;(2) an engineered soils report that (A) identifies the locations of borings, test holes, and percolation tests and describes how they are sufficient to adequately evaluate subsurface characteristics of the area planned for the initial and replacement soil absorption systems;(B) contains test hole or boring logs that includes information on soil classification, texture, structure, density, and moisture conditions;(C) if soils are not classified as SW or SP, includes a description of the method and the results of percolation tests of the receiving soils;(D) identifies the depth to groundwater and depth to any seeps encountered; and(E) identifies the depth to impermeable layers, including the presence or absence of permafrost and potential effect on system performance;(3) design drawings sealed in accordance with 12 AAC 36.185 - 12 AAC 36.245 that clearly and legibly depict the design on 8 1/2-inch by 11-inch or 11-inch by 17-inch paper format; the design drawings must include (A) scaled site plan that shows the buildings, all wastewater system components and area for replacement infiltrative area, all nearby drinking water sources labeled with the classification of the water system, all nearby surface water, and topography of the site;(B) the plan and profile of private and community sewer lines showing slope, cleanouts, and manholes with invert elevations;(C) profiles, cross-sectional drawings, or details of all system components as necessary to show methods of construction, bedding and backfill, and conformance with the requirements of 18 AAC 72.530 and standard sanitary engineering principles and practices;(4) additional supporting information including (A) specifications of materials, quality assurance and quality control parameters, engineer observations, and other information that will assist the department in evaluating whether the system design will be installed in accordance with the plan, approval;(B) if the system design flow, total on lot design flow, or facility-wide design flow is greater than 2,500 gallons per day, nitrate calculations that are prepared in accordance with standard sanitary engineering principles and practices, are sealed by a registered engineer, and demonstrate that nitrate concentrations in the groundwater aquifer that is most likely to be affected by proposed and existing systems will not exceed five milligrams per liter beyond a distance measured from the edge of the soil absorption field to the nearest downgradient property line, or to a point that the department identifies as necessary to protect public health, public and private water systems, and the environment; and(5) other information the department determines is necessary to assess the effect of the conventional wastewater system upon public health, public and private water systems, and the environment.(c) If the department requires additional information, or the application is determined to be incomplete, the department will notify the applicant. If the applicant fails to provide the additional information not later than 45 days after the department's request, the department will close the application as incomplete and the applicant must submit a new application and plan review fee.Eff. 10/1/2023, Register 247, October 2023Authority:AS 44.46.020
AS 44.46.025
AS 46.03.020
AS 46.03.050
AS 46.03.100