DESIGN CONSULTING ENGINEERS Engineers, Geotechnical, Environmental & Material Scientists

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1 DESIGN CONSULTING ENGINEERS December 12, 2013 Mr. Mark Kozlowski, P.E. Design Manager Chicago Public Schools Capital Improvement Program 125 S. Clark St. ; 17 th Floor Chicago IL, RE: Ravenswood Elementary School Sewer Cleaning and Televising [Project # SIT-GEO] Dear Mr. Kozlowski: As per your authorization we have completed the sewer cleaning, televising and video inspection at Ravenswood School according to the Scope of Services in the Job Order Contract. This letter report presents the results of our inspection work as requested. Scope of Services Perform four (4) sewer structures in the public right of way to upstream structures within the boundary of the project. Anticipate lf of sewer cleaning. Provide video recording services for the sewers and structures to be cleaned to document the structural integrity of the sewer and connections and to observe any deflections in the sewer where conditions may warrant sewer repair Provide a DVD of the sewer televising Provide a report and exhibit showing the locations of all televised sewers Description of Site Ravenswood Elementary School is located at 4332 N. Paulina St. in Chicago, IL. The existing manholes proposed for cleaning and televising are located south and east of the school building. Please see attached post inspection sketch of sewer system to identify structures and sewer lines in conjunction with DVD footage. Field Inspection - Cleaning and Televising Cleaning and televising work was performed based on the location map supplied as Ravenswood Geotech. High pressure jet rodding was utilized to perform cleaning of sewer system. Gen-Eye Underground Sewer Camera system with footage counter, time lapse and infrared lighting capabilities were used to televise and record the pipe conditions of the sewer system.

2 DESIGN CONSULTING ENGINEERS DCE inspector along with sewer cleaning/televising crew performed and monitored the cleaning and televising operation on December 9, Access to water spickets and electric outlets was provided by school engineer, Mr. Danny Williams. Manholes A total of 4 manholes, 1 cleanout and associated sewer lines were located and cleaned. A total of 3 manholes on the supplied location map were not found on site and may be buried. Sewer Lines The sewer lines cleaned and televised are combined sewers, pipe materials are vitrified clay pipes, approximately 6 in diameter. Sewer lines were cleaned via jet rod before televising was performed. Please see post inspection sketch, which may slightly differ from supplied location map due to field observations, sewer line description and length of televising is noted below. Description of Line / Length - 1.) MH#1 to West (right pipe) (Title 1 (Ch.1 & 2) of DVD) - 20 of televising, Televising ends near gutter, camera unable to televise further (possibly due to an upward elbow). 2.) MH#1 to West (left pipe) (Title 1 (Ch.3 & 4) of DVD) - 20 of televising, Televising ends near gutter, camera unable to televise further. 3.) MH#1 to East (left pipe) (Title 1 (Ch.4-6) of DVD) - 35 of televising, Televising ends at a buried basin. 4.) MH#1 to East (right pipe) (Title 1 (Ch.7) of DVD) - 7 of televising, Camera under water, unable to televise further. 5.) Cleanout to Northeast (Title 2 of DVD) - 24 of televising, Drops into sewer line at 10, Y-Section at 18 Televising ends at a buried basin at ) MH#2 to North (Title 3 (Ch.1&2) of DVD) - 85 of televising, Separation of joint noticed at 28 Possible broken piece of pipe noticed at 31 Fracture in pipe noticed at 85 Televising ends at 85, camera unable to televise further 7.) MH#3 to North (Title 4 (Ch.1&2) of DVD) - 8 of televising, Jet rodder and camera unable to travel beyond 8.

3 DESIGN CONSULTING ENGINEERS 8.) MH#4 to Northwest (top pipe) (Title 5 (Ch.1) of DVD) - 8 of televising, Upward elbow at 8, camera unable to televise further. 9.) MH#4 to Northwest (bottom pipe) (Title 5 (Ch.1&2) of DVD) - 75 of televising, Fracture noticed at 69, televising ends at a basin (possibly buried basin). 10.) MH#4 to East (Title 5 (Ch.2&3) of DVD) - 46 of televising, Ends at city sewer on Paulina St. 11.) MH#4 to South (Title 5 (Ch.3-5) of DVD) - 84 of televising, Ends at an upward elbow, camera unable to televise further. 12.) MH#4 to North (Title 5 (Ch.5&6) of DVD) - 37 of televising, Ends at 37 north, camera unable to televise further. Inaccessible and Damaged/Possible Repair Items: 1) As mentioned above, several sewer lines contain upward elbows, possibly connecting to gutters/roof drains and contributing to the inaccessibility of televising. However the following sewer lines are inaccessible due to unknown reasons: a.) MH#1 to East (right pipe) b.) MH#3 to North c.) MH#4 to North 2.) Several items which may warrant repair are noticed in a sewer line from manhole #2 in the north direction. The following was noticed: a.) Separation of joint noticed at 28

4 DESIGN CONSULTING ENGINEERS b.) Possible broken piece of pipe noticed at 31 c.) Misalignment of pipe joint noticed at 53 d.) Fracture in pipe noticed at 85 3.) A fracture in the pipe surface was noticed 69 northwest of manhole #4 (bottom pipe). See image below.

5 DESIGN CONSULTING ENGINEERS We appreciate this opportunity to be of service and look forward to working with you on future projects. If you have any questions on the subject, please call us. Very Truly Yours, DESIGN CONSULTING ENGINEERS Ahmad Nur Field Engineer Mannan Abdul, P.E. Project Manager Attachments: Post-inspection sketch DVD

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