Section 370.110  Scope and Applicability

a)         These design criteria apply to conventional design concepts for wastewater  collection and treatment systems.  Where non-conventional concepts or approaches to collection and treatment, particularly for very small systems, are being considered, the Agency should be contacted for any design guidance that may be available.

b)         In evaluating plans and specifications for new processes, the Agency will consider the specific information submitted with the design in accordance with the provisions of Section 370.520(b) for situations involving new process evaluation.

c)         These criteria are intended to establish limiting values for those aspects of plans and specifications which the Agency evaluates and to promote, as far as practicable, uniformity of practice throughout the State.  For projects with a design flow average of over 100 million gallons per day (mgd), the application of specific design parameters in these criteria should be evaluated on a unit-by-unit basis to insure optimum design performance and cost effective construction.  In applying these criteria, consideration must be given to the characteristics (including current water quality) and uses of the receiving stream in order to insure compliance with the applicable regulations of the Illinois Pollution Control Board (hereinafter "IPCB").  Users should also be cognizant of Federal requirements.

d)         The word "shall" is used where practice is sufficiently standardized to warrant compliance with specific requirements, or where safeguarding the public health or protecting water quality justifies such definite action.  Words such as "should", "recommended" or "preferred" indicate desirable procedures or methods with deviations subject to individual project consideration.

e)         Definitions of terms and their use are intended to be in accordance with the GLOSSARY – WATER AND WASTEWATER CONTROL ENGINEERING, jointly prepared by the American Public Health Association (APHA), American Water Works Association (AWWA), American Society of Civil Engineers (ASCE), and Water Environment Federation (WEF). The units of expression are in accordance with the WEF Manual of Practice Number 6, Units of Expression for Wastewater Treatment.

(Source:  Added at 21 Ill. Reg. 12444, effective August 28, 1997)