7 Del. Admin. Code § 7101-6.0 - Large Systems ([GREATER THAN] 2,500 Gpd)
This section applies to the permitting of large wastewater treatment and disposal system only. The permittee must obtain all necessary collection system permits separately in accordance with the State of Delaware's Department of Natural Resources and Environmental Control's Regulations Governing the Control of Water Pollution and any local or county requirements.
The Department will facilitate compliance with these Regulations through a review of the proposed development project. The project should be coordinated with the Department early in the development process to avoid unnecessary conflicts and expense.
A Soil Investigation Report must be submitted to the Department for review and approval for large on-site wastewater treatment and disposal systems (LOWTDS).
A Hydrogeologic Suitability Report must be submitted to the Department for review and approval for large on-site wastewater treatment and disposal systems (LOWTDS).
Work performed in connection with the HSR shall be completed by, or under the supervision of, a Delaware-licensed professional geologist (PG). Reports and related documents must bear the seal and signature of the PG overseeing the project.
General site and project details shall include, but not be limited to the following:
Geologic units containing the water-table aquifer and the first regional confining unit shall be identified and described in terms of formation name, lithology, approximate thickness, depositional environment, and stratigraphic relationships with other units. The saturated thickness of the water table aquifer shall be approximated based on available information. In some instances, the Department may require saturated thickness to be documented based on field data.
Aquifer properties (e.g. saturated hydraulic conductivity, transmissivity) shall be derived from on-site in-situ testing (e.g. slug test, pumping test). Wells installed to establish groundwater-flow direction may be used for aquifer testing, provided they are suitably constructed and necessary documentation is available. Standard methods shall be used to implement the testing and analyze the data. Testing methods shall be clearly documented, and all data shall be submitted digitally to the Department.
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Due to unforeseen site complexity, wells and surface water bodies or system design the Department may require additional work beyond the HSR requirements previously outlined.
A Surface Water Assessment Report (SWAR) must be submitted to demonstrate that nutrient performance standards for wastewater are being met at the post treatment location of a large on-site system or through natural attenuation processes prior to reaching the closest receiving surface water body in order to comply with surface water quality standards. Work performed in connection with the SWAR requires geologic interpretation. These assessments must be completed by, or under the supervision of, a Delaware-licensed professional geologist (PG). The SWAR and related documents must bear the seal and signature of the PG overseeing the project. The SWAR must be submitted to the Department for review and approval. The SWAR must contain the following:
Wastewater spray irrigation systems may be utilized on agricultural land, forest lands and other designated areas.
The applicant must develop and submit for the Department's review and approval, an operating protocol designed to ensure the high-level disinfection criteria is met before the wastewater is released to the storage system or to the wastewater reuse system.
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Unlimited public access sites are those landscaped areas such as golf courses, residential lawns, cemeteries, parks, and highway medians which may not have adequate buffer zones and are accessible to the public at all times.
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In order to obtain a permit to construct and operate an on-site wastewater treatment and disposal systems with daily flow rates of >= 2,500 gallons, a permit application must be submitted to the Department for review and approval. A permit application will not be reviewed by the Department until the SIR, HSR and SWAR have been reviewed and approved by the Department.
All large system construction permit applications must contain the following:
The Design Engineer Report is to be submitted for Department review by the owner or a designated agent. The report must include all applicable calculations and justifications for the overall design of the on-site wastewater treatment and disposal facility including pump stations and treatment processes. Once approved by the Department, the Design Engineer Report becomes the basis of design for the project. Once the facility is permitted, the facility must be constructed, operated and maintained in accordance with the Design Engineer Report. The Design Engineer Report must, at a minimum, address all of the following applicable items:
Design wastewater characteristics for new facilities must be in accordance with current industry averages. Expansions and phase upgrades must utilize actual parameter concentrations from monitoring results.
The plans must include, at a minimum, the following applicable items:
Upon completion of construction, an operation permit must be obtained from the Department prior to system operation. A classification shall be performed on the facility in accordance with Regulations Licensing Operators of Wastewater Facilities. The class of operator required for the facility will be determined by the Board of Certification for Licensed Wastewater Operators in accordance with the Regulations Licensing Operators of Wastewater Facilities. All large systems must be under the direction of a licensed operator. The licensed operator must be available at all times. The licensed operator shall be on-site at the time the system is put into operation and is to receive all training as necessary to properly operate the system.
Prior to the issuance of an operation permit, the following applicable items must be submitted. Failure to submit all required information constitutes grounds for denial of the operation permit.
The "as-built" drawings must include:
Conditions necessary for the protection of the environment and the public health may differ from facility to facility because of varying environmental conditions and wastewater compositions. The Department may establish specific permit conditions. Specific conditions may be established in consideration of characteristics specific to a facility and inherent hazards of those characteristics. Such characteristics may include, but are not limited to:
At least 180 days prior to the expiration date of the operation permit, the permittee must submit an application for renewal or notify the Department of the intent to cease discharging by the expiration date. The application package for systems with a design flow >= 100,000 gpd, must include a five (5) year Compliance Monitoring Report (CMR). In the event that a timely and complete application has been submitted as determined by the Department, and the Department is unable, through no fault of the permittee, to issue a new permit before the expiration date of this permit, the terms and conditions of this permit are automatically continued and remain fully effective and enforceable until a decision is made on the new application.
The provisions of a permit are severable. If any provision of a permit, or the application of any provision of a permit, to any circumstances is held invalid; the application of such provision to other circumstances, and the remainder of the permit, shall not be affected thereby.
Permits may be transferred to a new owner or operator. The permittee must notify the Department by requesting a change of ownership of the permit before the date of transfer. The transfer must be consistent with any notarized legal documents and/or CPCN required by these Regulations. The legal documentation must be provided with the application. The application must be received 30 days before the transfer.
A system may be designed in phases to allow actual flow data to be collected to determine the necessity and timing for treatment facility upgrades/additions and to accommodate initial low influent flows to the wastewater treatment plant.
The permittee must submit a written report to the Department for review and approval of any changes to the facility or construction of the system within the following time periods:
Following the construction of the facility, the permittee shall submit an O&M Plan detailing the operations of the wastewater treatment facility, the conveyance system, and the disposal system to the Department for review. The permittee shall operate and maintain the land treatment system in accordance with the approved O&M Plan. The O&M Plan must include, but not limited to, the following:
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where s is the standard deviation around the mean
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* A significant change in soil pH is defined as a change of one (1) or more standard units (S.U.) from the original value established in the Design Engineer Report.
** Excessive levels of soil phosphorus are defined by the Delaware Nutrient Management Commission. Soil phosphorus levels must be tested in accordance with the University of Delaware soil testing methods (Gartley, 2002). If the soil phosphorus levels become excessive, the permittee must perform a Phosphorus Site Index (PSI) study. The results must be submitted to the GDS within 30 days of study completion. Based on these, the GDS may require the permittee to submit a plan detailing steps to reduce the phosphorus loading rates at the site.
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Delaware Department of Natural Resources and Environmental Control
Groundwater Discharges Section/Large Systems Branch
89 Kings Highway
Dover, DE 19901
Telephone: (302) 739-9948
Fax: (302) 739-7764
Requests for monitoring modifications must be submitted to the Department in writing. Such requests must clearly state the reason for and nature of the proposed modification and, where applicable, must contain supporting scientific information, analysis, and justification. Requests will be addressed by the Department on a case by case basis.
A permit must be obtained from the Department prior to the construction, operation, maintenance or repair of a temporary holding tank. In order to obtain a permit, the applicant must submit a permit application (see Section 6.10.3) to the Department for review and approval. A temporary holding tank permit shall not exceed a five (5) year period and may be extended at the discretion of the Department.
Monitoring requirements for the treated wastewater provided to all recipients must be as follows unless otherwise stipulated in the operation permit.
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If the treated wastewater is to be reused for irrigation activities, background and decennial soils sampling must be performed for the parameters listed below. A minimum of one (1) composite sample must be taken for each 50 acre area, unless otherwise provided in the permit.
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Agricultural use of distributed treated wastewater is the distribution of treated wastewater to farmers for irrigation of agricultural crops in accordance with3Del.C.§ 2301. Sites using treated wastewater in accordance with 3Del.C.§ 2301 which have incorporated the use of treated wastewater in a Delaware Department of Agriculture approved Nutrient Management Plan are exempt from the requirements of Sections 6.0 through Section 6.10, and Section 6.12 of these Regulations unless specifically referenced within this Section 6.11. Wastewater treatment facilities proposing to distribute treated wastewater for agricultural use must comply with all requirements set forth in Section 6.11 and must adhere to the requirements of this Section 6.11.8.
The Department has established a schedule of annual and/or one-time fees. One-time fees shall be submitted to the Department at time of application. Annual fees shall be submitted to the Department upon receipt of notice or in accordance with the fee payment schedule. Failure to pay fees constitutes grounds for denial of permits and revocation of previously issued permits.
If any part of these Regulations, or the application of any part thereof, is held invalid or unconstitutional, the application of such part to other persons or circumstances and the remainder of these Regulations shall not be affected and shall be deemed valid and effective.
Notes
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