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The 39th Street conduit is the Metropolitan Water Reclamation District of Greater Chicago's (District's) oldest and largest intercepting sewer. The most cost-effective method to rehabilitate the 6.10 meter (20 foot) diameter brick sewer was to complete the project in two phases, limiting service disruption and flooding risk. Phase 1, completed in 2012, consisted of a deep...

When a total R-value of 0.7 was reported for a major flow basin in an I/I study in the City of Columbus, it raised some eyebrows. A total R value of 0.70 meant that 70% of the rain water falling on the basin was making its way into the sewer system. Most shockingly, the sewer had only a very small section of combined sewer; it was almost entirely a separate sanitary sewer! When these extremely...

A chlorine system conversion project at the 91st Avenue Wastewater Treatment Plant was initiated to convert the bulk chlorine system which consisted of four 20-ton permanent storage tanks and two 17-ton mobile truck trailer mounted system to a multiple one-ton cylinder system. The project also included the replacement of plastic pipe used for the conveyance of both chlorine gas (vacuum) and...

Dropping sewage from near surface collection systems into deep tunnels involves a number of challenges, including the odor control, air entrainment, solids management, energy dissipation, surge control, and access for personnel and equipment. The use of drop structures to handle large flows will become more prevalent over the next several years due to the large number of Combined Sewer Overflow...

Integrated design strategies in closed loop recirculating aquatic systems (RAS) enables unit operation refinement and process consolidation. With federally mandated increases in the levels of required waste water treatment, continued improvements in their economic competitiveness has resulted in closed loop systems receiving increased application in a wide variety of aquatic industries. The...

The City of Columbus, Ohio is under two consent orders from the Ohio Environmental Protection Agency (OEPA) related to wet weather issues. These issues were addressed in 2005 through the development of a Wet Weather Management Plan that dealt with both Combined Sewer Overflows (CSO) and Sanitary Sewer Overflows (SSO). A critical component of the plan was the affordability analysis. The City...

WEFTEC, the largest event of its kind in North America, offers water quality professionals the best in water quality education and training. With almost 200 technical sessions, workshops, mobile sessions, local facility tours and 1,000+ exhibitors, it is the premier water conference! The WEFTEC technical program is selected through a rigorous, peer-review process, ensuring that attendees experience the highest-quality education. WEFTEC speakers are experts and innovators, leading the way in water quality. The following paper was presented at WEFTEC 2017.

Lehigh Cement Company has conducted preliminary and in depth testing of Class A dried biosolids (DBS) as a fuel replacement in our cement kiln at Union Bridge, Maryland. Lehigh's parent company, Heidelberg Cement, has been using DBS in European cement kilns for several years. These programs have proved the safety and environmental soundness of this concept. Lehigh's ongoing development of these...

 

The wastewater industry is increasingly striving to reduce operations costs while producing effluent with low nutrient concentrations. This paper presents the “A2B” Process, a novel strategy for carbon redirection that can have advantages over the traditional adsorption/bio-oxidation (A-B) process, as it is easier to implement and operate in a range of conventional Biological Nutrient...

The European-style A/B process utilizes a very high rate activated sludge (HRAS) A-stage operated at a low sludge age and low DO. The aim of the HRAS process is to provide a cost effective means of removing carbon while decreasing aeration demand and volume required for the subsequent B-stage process, which usually consists of biological nutrient removal (BNR). A pilot study to evaluate the...