Section 905.110 Effluent Discharges


a) General. Buried sand filters, re-circulation sand filters, waste stabilization ponds, aerobic treatment plants and NSF International/ANSI Standard 40 wastewater treatment systems listed by NSF International/ANSI Standard 40 as Class I effluent (see Section 905.100(a) and (c)) or any Department approved or accepted system may be discharged to any one of the following 3 options:


1) A receiving stream, river, lake or pond that provides greater than a 5:1 dilution of the effluent, based on the 7-day, 10-year low flow rate. A discharge within 10 feet of one of these receiving bodies of water shall be considered to be a discharge to the receiving body of water. Discharges greater than 10 feet from the receiving body of water shall comply with subsection (a)(2) or (3). Discharges to a lake or pond shall be limited to 2 discharges per surface acre of water. More than 2 discharges may occur per individual surface acre of water; however, the total number of discharges to total surface acres of water shall not exceed a ratio of 2:1. An example of this is as follows: In a 20-acre lake, several discharges may enter the lake in a -acre cove; however, the total discharges entering the lake would be limited to 40. Where discharges are not equally distributed around a lake or pond, the Department or local authority shall be consulted to assure that nuisance conditions are not created.


2) A common collector, provided that the collector does not discharge within one mile upstream from a public water supply intake, public bathing beach, or to any public use area. A public use area is any area that is frequently used by the public. Examples of a public use area are playgrounds and picnic areas. Discharges from lots platted (e.g., individual lots, subdivisions, commercial developments) after January 1, 2014 are not eligible to discharge into a common collector.


3) The ground surface, where the discharge points of private sewage disposal systems with surface discharges do not exceed an average of one per acre and the effluent does not pond or create a nuisance condition.


b) Whenever a subdivision is platted that does not provide private sewage disposal systems in compliance with Section 905.60 or subsection (a) of this Section, then a sewage system in compliance with 35 Ill. Adm. Code 301 shall be provided.


c) When lots have been platted prior to March 15, 1996, the applicant for plan approval or local authority approval may apply for a variance to this Section in accordance with the provisions of Section 905.20(l).


d) Effluent Limitations


1) Surface discharging private sewage disposal systems shall not exceed the following effluent standards:


A) The system shall comply with NSF International/ANSI Standard 40, Section for carbonaceous 5-day biochemical oxygen demand (CBOD5) and Section for total suspended solids (TSS).


B) No effluent shall contain settlable solids.


C) Color, odor and turbidity shall be reduced to below discernable levels.


D) No effluent shall contain floating debris, visible oil, grease, scum or sludge solids.


E) Fecal coliform bacteria concentration shall not exceed 400 organisms per 100 ml.


F) Sample Ports. After January 1, 2014, any surface-discharging system installed, repaired, renovated or replaced shall have a sample port of at least 4 inches in diameter or free-fall discharge of at least 12 inches located after the disinfection component, which extends to 3 inches or more above the ground surface. A sample port is not required if a free-fall discharge is within 200 feet of the disinfection device. The sample cannot be taken from a common collector or drainage tile, but must be taken from a discharge point that discharges only the treated effluent from the surface- discharging private sewage disposal system.


G) A surface-discharging system installed after January 1, 2014 shall not discharge to a roadside ditch as stipulated in the Illinois Highway Code [605 ILCS 5/9-123].


2) Samples shall be analyzed in accordance with the Standard Methods for the Examination of Water and Wastewater.


e) Private sewage disposal systems designed to be compliant with subsection (d) can be discharged to a subsurface seepage field designed and constructed to be at least ⅔ the size determined necessary by Section 905.60. The subsurface system shall be installed to be as shallow as possible while maintaining a minimum of 6 inches of cover and one foot of separation from the bottom of the trench to the shallowest limiting layer.


(Source: Amended at 37 Ill. Reg. 14994, effective August 28, 2013)