Illinois Administrative Code
Title 35 - ENVIRONMENTAL PROTECTION
Part 306 - PERFORMANCE CRITERIA
Subpart F - SITE SPECIFIC RULES AND EXCEPTIONS
Section 306.502 - Alton Combined Sewer Overflow Discharges

Universal Citation: 35 IL Admin Code ยง 306.502

Current through Register Vol. 48, No. 12, March 22, 2024

a) The discharge from the Piasa-State Street Sewer at Mississippi River mile 202.64 is not subject to 35 Ill. Adm. Code 304.106, 304.120, 304.121 and 304.124 during the following conditions:

1) Before replacement of the existing Locks and Dam 26, when the tailwater elevation exceeds 415.3 Mean Sea Level (MSL); or

2) After replacement of Locks and Dam 26, when the pool level exceeds elevation 420 MSL at Mississippi River miles 203.12 and 203.22 (Piasa and State Street Outlets relocated).

b) Discharges from the City of Alton at Mississippi River miles 201.66 (Shields Valley), 202.24 (Central Avenue), 203.12 (Piasa Outlet), 203.22 (State Street Outlet), 203.61 (Summit Street), 203.87 (Bluff Street) and 204.30 (Turner Tract), are subject to the following conditions:

1) The overflow structures and the associated interceptor sewer must be protected against intrusion by flood waters and be maintained operational at flood stages from Mississippi River backflow for a 25-year Mississippi River flood stage, except as follows:

Overflow Structure

River Mile

Protection Level Mean Sea Level (MSL) River Stage

Piasa Outlet

203.12

420.0

State Street

Outlet

203.22

420.0

Summit Street

203.61

426.7

Bluff Street

203.87

426.7

Turner Tract

204.30

426.7

2) The City of Alton must maintain the south side interceptor sewer system in working condition to ensure that the system will flow at a maximum capacity.

3) No later than the date of completion of Lock and Dam 26, the south side interceptor pump station must be upgraded to a design capacity of a minimum of 13.7 million gallons per day.

c) Discharges from the combined sewer overflows designated in subsection (b) are not subject to the treatment requirements of Section 306.305(a) and (b) provided that:

1) The City of Alton maintains the south side interceptor sewer system in working condition to ensure that the system will flow at a maximum capacity.

2) The South Side interceptor pump station must be upgraded to a design capacity of a minimum of 13.7 million gallons per day.

Disclaimer: These regulations may not be the most recent version. Illinois may have more current or accurate information. We make no warranties or guarantees about the accuracy, completeness, or adequacy of the information contained on this site or the information linked to on the state site. Please check official sources.
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