Del. Admin. Code tit. 7, 7000, 7100, 7101
FORWARD
The Department of Natural Resources and Environmental Control (the Department) finds that a substantial portion of the State's population lives where centralized water supplies or wastewater treatment services are limited. It is the intent of the Department to aid and assist the public in the installation of on-site wastewater treatment and disposal systems, where possible, by utilizing the best information, techniques and soil evaluations for the most suitable system that site and soil conditions permit.
Statewide Regulations Governing the Design, Installation and Operation of On-Site Wastewater Treatment and Disposal Systems have existed since 1968. Inappropriate installations and poor operation and maintenance practices resulted in disposal system malfunctions. Inadequately renovated wastewater contaminated the State's ground water and presented a threat to the public health, safety, and welfare. Corrective measures required the replacement of water supply and wastewater systems at a very high cost which was sometimes borne by the general public. After years of working under the Regulations which were first implemented in the 1960's, numerous deficiencies were found to be present within the same. Given this, the Department concluded that significant revisions to its Regulations.
In considering these findings, the Department determined that the adoption of effective Regulations was the proper course of action. Through a process that included considerable staff research, public meetings and presentations, public workshops, a public hearing and a hearing officer's report along with four draft versions of these Regulations were prepared, reviewed and revised. This final version is the result of those various activities, and incorporates, as best as possible, all valid concerns into its provisions.
The purpose of these Regulations, is to prevent the problems listed above. They are based on the best information available and include the establishment of a process for updating Regulations as information changes. They include what are considered to be the best engineered design standards for on-site systems, as determined by research and practical experience. These Regulations seek to require the use of on-site systems that will function according to their performance criteria without causing the State's ground water resources to violate U. S. Environmental Protection Agency Drinking Water Standards on an average annual basis. Wastewater management actions necessary to achieve those standards were recommended to the Department in Delaware's 1983 Comprehensive Committee's Final Report which has since been adopted as state policy.
The proper siting of systems is addressed by the establishment of various soil criteria which lead to the selection of the most suitable on-site wastewater treatment and disposal system for local conditions. System selection and sizing are determined using the results of the site specific soil evaluations and percolation tests. Density is addressed by the adoption of minimum lot sizes tied to appropriate treatment and disposal techniques, and in some cases, the use of scientific ground water and geological analyses that both assure renovation of degradable pollutants and dilution of wastes which are inadequately treated in the soil. Site evaluation and system selection, design, installation and pump-outs are required to be performed by individuals licensed under these Regulations. Alternative system design criteria were established to enable proper waste treatment and disposal to occur in locations where conventional systems would be inappropriate. With the advent of mortgage companies requiring wastewater system inspections prior to loan approval, the Department took a pro-active approach to create a new licensee category (Class H System Inspector) and standardized format to perform the inspection so all inspections will be evaluated under the set of criterion. Finally, a specific variance procedure is established to provide an opportunity to reconsider any provision of these Regulations, provided that proper public disclosure and adequate consideration of the consequences are provided.
In developing these Regulations, the Department operated under the philosophy that where soil and site conditions permit, the least complex, easy to maintain and most economical system should be used. Although it has not been possible to include directly every method of on-site treatment and disposal, the Department's policy is to encourage development of systems, processes and techniques which may benefit significant numbers of people within Delaware. It is expected that these Regulations will be reviewed and revised periodically and that standards for other alternative systems will be prepared as more experience and research data become available. The Regulations contain provisions that enable that process to occur.
Del. Admin. Code tit. 7, 7000, 7100, 7101