Photo 3.1.75. January 29, 1923. Some of the workers are looking down at their co-workers below in the control chamber at Ninety-Seventh Street and Avenue N. The control chamber regulates the flow through the three-barrel syphon. A small dam forces dry weather flow through two smaller barrels. Wet weather flow will overtop the dam and flow through the larger upper barrel. (MWRD photo 9629)

Photo 3.1.76. January 29, 1923. Hydraulic cylinders force the shield to penetrate the sand before the sand is removed. After installation of tunnel supports, the sewer is constructed in the tunnel. The third tunnel was also constructed by the shield method under a railroad embankment in Avenue N between Ninety-Eighth and Ninety-Ninth streets. The 500-foot long tunnel was constructed through water-bearing sand. (MWRD photo 9620)

Photo 3.1.77. January 29, 1923. An Illinois Bell Telephone Company employee is repairing a cable damaged during construction of the control chamber. The control chamber at Ninety-Eighth Street and Avenue N regulates the flow from local sewers into the intercepting sewer. (MWRD photo 9630).

Photo 3.1.78. September 6, 1922, looking north along Avenue N toward Ninety-Ninth Street. Low ground and sandy soils require bracing the sewer trench sidewalls to prevent a cave-in and well points to drawdown the groundwater level during construction. Construction is not possible in water bearing sandy soils without these measures. (MWRD photo 9470)

Photo 3.1.79. September 6, 1922, looking north in Avenue N from 100th Street, showing excavation where a Chicago water main was removed. The water main interfered with construction of the sewer and was replaced after sewer construction. (MWRD photo 9473)

Photo 3.1.80. September 28, 1922, looking north and down into the sewer trench in the intersection of Avenue N and 100th Street. Large timber poles laying across the trench support a high voltage Commonwealth Edison Company cable conduit and a 42-inch Chicago sewer. Underground utilities pose challenges when constructing sewers. (MWRD photo 9511)

Photo 3.1.81. September 6, 1922, looking south in Avenue N from 100th Street, showing the route of the section 11 sewer. Local sewers in cross streets will be connected to the intercepting sewer, eliminating the discharge of raw sewage to the east side of the Calumet River. (MWRD photo 9471)

Photo 3.1.82. September 28, 1922. The 8.8-foot section 11 intercepting under Avenue N south of 100th Street is a tight fit in the braced sewer trench. In addition, another underground utility has to be suspended. Finding an underground cable or pipeline was often a surprise to contractors. Owners of underground utilities didn’t often share location information. (MWRD photo 9512)

Photo 3.1.83. September 28, 1922, looking north at the intersection of Avenue N and 101st Street, showing the lack of pavement on Avenue N. Only 101st Street is paved through the intersection. A public sidewalk exists in front of the buildings. (MWRD photo 9515)

Photo 3.1.84. October 22, 1922, looking south on Avenue N midway between 101st and 102nd streets. The unimproved road materials have been removed and well points installed on each side of where the sewer trench will be excavated. (MWRD photo 9577)

Photo 3.1.85. June 13, 1923. The sewer is being constructed at 110th Street by the open-cut method through the sparsely populated area. Well points are still needed to lower the groundwater level. Planning for residential growth, section 11 extended to 112th Street under Avenue O after turning at 102nd Street. The last local sewer connection was at 106th Street. (MWRD photo 9805)

Photo 3.1.86. September 7, 1923, looking south on Harbor Avenue. The sewer is completed to about 350 feet northeast of Brandon Avenue. Note the unbraced trench and well points. Section 12 ran north from Ninety-Fifth Street under several railroad tracks, then northeast under Harbor Avenue to about 9100 South. (MWRD photo 10008)

Photo 3.1.87. September 7, 1923. Section 12 ended at The Strand, a street fronting the Illinois Steel Company, that is long gone, replaced by South Lake Shore Drive. Looking south, The Strand is viewed from the centerline of the block between Harbor Avenue and Ninetieth Street. (MWRD photo 10019)

Photo 3.1.88. September 7, 1923, looking north along The Strand from the center of the block, showing a wide sidewalk with curb and street lights. East of The Strand is the Illinois Steel Works, later known as the South Works of the United States Steel Corporation. The works and the corporation no longer exist. (MWRD photo 10020)

Photo 3.1.89. September 19, 1923, looking south, showing completed sewer and the beginning of a safer braced sewer trench. The bracing began at about Ninety-Third Street and continued to the end of the sewer. (MWRD photo 10086)

Photo 3.1.90. September 19, 1923, looking west. The Ryan Company, contractor on section 12, has a new self-propelled track-mounted steam shovel. The shovel is stripping pavement northeast of Ninety-Third Street. Spectators are watching the new machine perform. (MWRD photo 10087)

Photo 3.1.91. October 3, 1923, looking northeast. The eastbound track is suspended over the sewer excavation while a west bound trolley passes by. East bound trolly service was rerouted until the suspended track could be supported. Ninety-Second Street hosted a busy streetcar line that continued southeast on Ewing Avenue. Sewer work could only interrupt streetcar service for short periods of time unless major work required rerouting of the street cars. (MWRD photo 10133)

Photo 3.1.92. October 3, 1923, looking northwest over the Ninety-Second Street and Harbor Avenue intersection. Workers are using pneumatic hammers to break up an unexpected deposit of steel mill slag under the tracks. The intersection under both tracks will be excavated for a control chamber on the local 36-inch sewer. (MWRD photo 10134)

Photo 3.1.93. October 3, 1923, looking southwest along Harbor Avenue. A clamshell bucket is being used to excavate the sewer trench and space for the control chamber. Cleats are attached to hold the ties to the rails. Sewer trench bracing and well points are used throughout Harbor Avenue due to high groundwater in the sandy soil. (MWRD photo 10135)

Photo 3.1.94. October 8, 1923, looking northeast along Harbor Avenue at the Mackinaw Avenue intersection. A 15-inch local sewer directly connects at this point without a control chamber. Section 12 ends 1,000 feet farther at The Strand where a control chamber will be built for a 60-inch local sewer. The sky is smoky over the Illinois Steel Works. (MWRD photo 10159)

Photo 3.1.95. January 30, 1924, looking over the contractor’s yard near South Chicago and Harbor avenues. The tall structure in the background is the head house above the shaft for the tunnel under the railroads and to its right are stockpiles of concrete materials. In the foreground is a second shaft for the tunnel work. (MWRD photo 10443)

Photo 3.1.96. February 26, 1924, looking west. The tunnel under the railroads from Ninety-Fifth Street to the wet weather outfall at Howard Slip is 1,100 feet long. For 900 feet, section 12 is double-barrel with the smaller barrel on top of the larger barrel. The tunnel heading is about 20-feet tall to accommodate the sewer. (MWRD photo 10473)

Photo 3.1.97. April 11, 1924. At Ninety-Fifth Street, the tunnel meets with a large, brick, local sewer, leading to the Chicago pumping station. However, after construction of the double-barrel sewer in the tunnel, a bulkhead will be built in the lower barrel. Sewage will flow to the pumping station in the upper barrel and wet weather flow will await construction of the new District pumping station. (MWRD photo 10523)

Photo 3.1.98. April 11, 1924, looking northeast, showing the bend in the tunnel under Harbor and South Chicago avenues. The lower barrel will continue to the east, ending at the outfall on Howard Slip, and the upper barrel will peel off to the northeast to continue under harbor Avenue. (MWRD photo 10525)

Photo 3.1.99. May 15, 1924, looking southwest. The outfall structure is under construction within the cofferdam at right. Old pilings in the left foreground mark the west end of Howard Slip. The large gas holding tank in the background is located on Baltimore Avenue and Ninety-Sixth Street. (MWRD photo 10607)

Photo 3.1.100. May 15, 1924, looking east. A pile driver is setting steel sheeting for a cofferdam needed for construction of the outfall structure. The sheeting will be removed when construction of the outfall is complete. The slip is parallel to and immediately north of Ninety-Fifth Street. (MWRD photo 10608)

Photo 3.1.101. June 5, 1924. Workers are beginning to build the wood form work. Braced timber sheeting was used for the rear and sides of the cofferdam due to the depth of the structure and the railroad embankment behind it. The invert of the outfall is 22 feet below the normal water level of the Calumet River. (MWRD photo 10676)

Photo 3.1.102. June 12, 1925. One year later the outfall structure is complete and some of the cofferdam remains in place. Looking south, backfill is needed on the back side of the structure to provide lateral support for the adjacent railroad embankment. (MWRD photo 11804)

Photo 3.1.103. March 4, 1926. The new pumping station has been completed and the outfall is used for wet weather discharge. The outfall openings are below the water surface. (MWRD photo 12517)

Photo 3.1.104. November 10, 1921. Section 9 intercepted sewers flowed south to the Little Calumet River under State Street and Wentworth Avenue and conveyed the sewage and stormwater to the Calumet Sewage Pumping Station. The tunnel head house is for the shaft leading to the tunnel. (MWRD photo 8635)

Photo 3.1.105. November 28, 1921. The tunnel was necessary due to the depth of the two local sewers. A 6.5-foot sewer was built in the tunnel under 124th Place. There were no railroads to cross under and the clay soil made tunneling easier than in sand. (MWRD photo 8680)

Photo 3.1.106. August 25, 1925, looking northwest across the intersection of Ninety-Fifth Street and Baltimore Avenue. A very complicated construction project is underway. Complications were caused by the number of electric, gas, sewer, and water conduits that had to be supported and worked around to connect intercepting sewers to the new pumping station. (MWRD photo 12093)

Photo 3.1.107. August 25, 1925, looking east in Ninety-Fifth Street. The old pumping station is at right and numerous railroads are overhead. Under this intersection, the section 12 wet weather lower barrel was connected to the section 1 wet weather discharge from the pumping station, and a local sewer in Ninety-Fifth Street plus the section 12 upper barrel were connected to the section 1 upper barrel influent sewer. (MWRD photo 12096)

Photo 3.1.108. September 8, 1925, looking northwest. Large timber poles were used to support a 100-kilovolt electrical cable, 16-inch gas main, and a 36-inch water main. (MWRD photo 12109)

Photo 3.1.109. September 8, 1925, looking south and down from the elevated railroad. The underlying sewer connections are barely visible because of the overlying utility lines. The excavation occupies almost the whole intersection. The new pumping station, out of the view to the south, is much larger than the old pumping station shown in the background. (MWRD photo 12111)

Photo 3.1.110. October 27, 1925. The intersection between the 36-inch water main and the upper barrel of section 12. The resolution left the water main in place and the cross-section of the upper barrel modified to pass under the water main with sufficient capacity. (MWRD photo 12233)