North Side Intercepting Sewer No. 6, looking northwest around the curve under the intersection of Melrose Street and Washtenaw Avenue, April 13, 1925. This section is completed except for the floor, which has been filled in for a flat surface while construction continues. The false floor will be removed before contract completion. (MWRD photo 11661)

Looking south at the Belmont Avenue junction chamber under construction, April 13, 1925. The intercepting sewer reduces from 10.5 to 8.5 feet in height on the right, as the flow from the Belmont Avenue sewer enters from the left. This junction chamber is in Washtenaw Avenue just north of Belmont Avenue. (MWRD photo 11662)

February 19, 1925. Looking west across the channel, the outfall is at the stern of a docked boat. The outfall for the Belmont Avenue city sewer discharges to the North Branch at the southwest corner of the bridge. Sewage in this sewer is intercepted at Washtenaw Avenue. The Concordia Evangelical Lutheran Church in the background was built is 1892. (MWRD photo 11542)

Looking east in George Street from Elston Avenue, November 3, 1925. A shaft house under construction for North Side Intercepting Sewer No. 7. The intercepting sewer was 7.5 feet high from Barry Avenue to the Diversey/Elston/Western intersection and 5 foot high thereafter to Fullerton Avenue. (MWRD photo 12275)

This shaft is located at Rockwell Street and Barry Avenue on North Side Intercepting Sewer No.8. Looking northwest, the contractor is beginning to mix a load of concrete for sewer construction, March 18, 1926. The building in the background is one of several small tanneries in the area. (MWRD photo 12535)

Perhaps 8,000 of these standard sewer manhole covers are spread throughout Cook County, allowing access to the underground network of intercepting sewers, control chambers, and other vaults. Weighing about 70 pounds, the weight is only one deterrent to removing the cover as each cover is locked with a simple yet clever mechanism. The 21-inch-diameter opening in the frame into which the cover rests, limits the size of people and equipment going underground. (Photo by author)

Looking southeast from the Dempster Street Bridge over the North Branch, November 14, 1919. Construction of the Morton Grove Sewage Treatment Works. The original plant, consisting of an Imhoff tank, small building, and sludge drying bed in the center, is being expanded to the right with a trickling filter in the building and final settling tanks. The sludge drying bed is also being expanded in the center. (MWRD photo 7374)

September 12, 1920. The Morton Grove plant is completed; the discharge to the North Branch is obscured by the overgrowth. The Morton Grove station on the Chicago, Milwaukee and St. Paul railroad (presently the Metra Milwaukee District North Line) is a block south along the tracks at right. (MWRD photo 7820)

October 24, 1927. The Glenview Sewage Treatment Works has been in service for three years. In the left foreground are the covered Imhoff tank and the open sludge drying beds. At center is the pumping station building and covered final settling tank. The open trickling filter, with sprayers in operation, is in the right background. (MWRD photo 13533)

March 26, 1925. The Northbrook Sewage Treatment Works are under construction, a near replica of the Glenview plant. All three of these suburban plants were removed from service when the intercepting sewer network reached the respective municipality and sewage could flow by gravity to the plant in Skokie. (MWRD photo 11642)

Construction of the North Side Sewage Treatment Works began in 1923. The first work was laying a 24-inch drain for the site north of Howard Street and west of the North Shore Channel. A steam shovel excavating the drain trench is loading spoil into dump cars, September 27, 1923. The drain discharged to the channel. (MWRD photo 10114)

October 19, 1923. Excavation for the huge aeration battery C at the North Side Sewage Treatment Works was well underway when a storm caused the excavation to fill with floodwater, inundating a steam shovel. To the north in the background are a gas holding tank, smokestack, and building at the manufactured gas plant on Oakton Street. (MWRD photo 10204)

The contractor’s construction yard, looking northeast from the top of the south cableway tower, July 17, 1924. The spur line off the Mayfair Division railroad is to the right. At left is the manufactured gas plant, and in the center background across the North Shore Channel is a brick making plant, both being on Oakton Street. Also, from left to center is construction of the embankment for a new electric line (today’s CTA Yellow Line). (MWRD photo 10931)

Beginning the pouring of concrete for the deep foundation of the Pump and Blower Building, April 8, 1926. The contractor is using guyed tower cranes, the type typical of the time. The taller more distant tower is adjacent to the concrete mixing plant and is used to aerially transfer batches of concrete to the shorter closer tower, from which the concrete flows via the long sloping pipe. The outstanding arm of the shorter tower is also used for hoisting materials. (MWRD photo 12548)

Looking northwest, about 40 feet below grade, April 22, 1926. The Pump and Blower Building pump suction chamber construction. The lineup of reinforcing bars indicates where walls in the pump suction chamber will be built to guide the influent sewage to pump intakes; the circular formwork shows the location of one of six cast iron pump suction bells. (MWRD photo 12606)

Looking northwest, October 29, 1926. Erection of the structural steel skeleton of the Pump and Blower Building for the plant. The skeleton will be enclosed with brick masonry and limestone detailing. The pumps and blowers are in a large sky-lighted interior atrium. (MWRD photo 13092)

December 27, 1926. On the lower pump floor at left, the intake and discharge piping awaits installation of the pumps and motors. The structural skeleton has been completed, but the masonry walls must wait for warmer spring weather. A rail spur into the building at right on the blower floor facilitates equipment deliveries and unloading with the building gantry crane. (MWRD photo 13126)

August 2, 1928. In this overview of the Pump and Blower Building interior, only four of the six pumps and five of the seven blowers are completely in view. The sixth blower in the right foreground is not completely assembled. The seventh blower and two pumps are out of view. (MWRD photo 14207)

From the southeast along McCormick Road, October 16, 1927. The Pump and Blower Building exterior and what appears to be a main entrance. The decorative entrance is not used; the working entrances are on the north and west sides of the building. Howard Street, an unimproved two-lane road at this time, is just out of view on the left. As shown by the sign, John Griffith & Son Company, Builders, was the contractor for this building. (MWRD photo 13506)

Earlier in late Jan. or early Feb. 1927, the exterior of the southeast corner of the Pump and Blower Building is still being installed, while interior electrical and mechanical work is underway, using the large door for access on the west side of the building. The rail spur in the building in Photo 4.54 was routed through this door. The construction activity at the southwest corner is for the underground sewage discharge conduit that runs under the Mayfair Division tracks. (MWRD photo 13177)

July 20, 1926. The floor of the diverging structure has been completed and ironworkers are preparing the reinforcing rods for wood forms for the exterior confining walls and internal guide walls. The sewage conduit from the Pump and Blower Building runs west underground to the Grit Building, where it diverges into several channels for the grit tanks and fine screens. (MWRD photo 12858)

The Grit Building, viewed from the east on January 27, 1927, is being enclosed with masonry walls and a flat roof with skylight. The outline of the diverging structure can be seen immediately east of the building; it will be covered with a sidewalk and road. The preliminary settling tanks are barely visible west of the building; the aeration batteries are at right. At right the cableway tower is used for work on the preliminary tanks. (MWRD photo 13176)

Looking east at the discharge side of the Grit Building, August 18, 1926. Channels from grit tanks and three fine screens converge to flow on to the preliminary settling tanks. Each channel is controlled by a sluice gate on the intake and discharge sides of the Grit Building so that individual tanks can be taken out of service for maintenance. (MWRD photo 12913)