| #D001 | | direct dischargers | A point source that discharges pollutants to waters of the United States, such as streams, lakes, or oceans. | high |
| #D002 | | indirect dischargers | A facility that discharges pollutants to a publicly owned treatment works (municipal sewage treatment plant). | high |
| #D003 | | Forming | is the set of manufacturing operations in which metals and alloys are made into semi-finished products by hot or cold working. | high |
| #D004 | | Nonferrous metal | is defined as any pure metal other than iron, copper, or aluminum; or metal alloy for which a metal other than iron, copper, or aluminum is its major constituent by weight. | high |
| #D005 | | Alloys | are considered as only one metal type. The metal type of any particular alloy is defined to be the metal that is the major component in percent by weight except for precious metals (silver, gold, platinum, and palladium) and beryllium. | high |
| #D006 | | Forming operations | rolling (both hot and cold), extruding, forging, and drawing; also cladding, tube reducing, swaging, and metal powder production. | high |
| #D007 | | Ancillary operations | casting for subsequent forming, heat treatment, surface treatment, surface coating, alkaline cleaning, solvent degreasing, product testing, and wet air pollution controls on forming operations and the associated operations. | high |
| #D008 | | Precious metal alloy | Any alloy containing 30 or greater percent by weight of precious metals is considered a precious metal alloy. | high |
| #D009 | | Beryllium alloys | any alloy in which beryllium is present at 0.1 percent or greater by weight. | high |
| #D010 | | Metal powders | include nonferrous metals and alloys as previously described, along with iron, copper, and aluminum and their alloys. Metal powder production processes include milling, abrading or atomizing. | high |
| #D011 | | Surface treatment | any chemical or electrochemical treatment applied to the surface of the metal. | high |
| #D012 | | NFMF | Nonferrous Metals Forming and Metal Powders | high |
| #D013 | | NAICS | North American Industrial Classification System | high |
| #D014 | | NPDES | National Pollutant Discharge Elimination System | high |
| #D015 | | NAICS | North American Industrial Classification System | high |
| #D016 | | BPT | Best Practicable Control Technology Currently Available | high |
| #D017 | | NSPS | New Source Performance Standards | high |
| #D018 | | NPDES | National Pollutant Discharge Elimination System | high |
| #D019 | | NAICS | North American Industrial Classification System | high |
| #D020 | | BPT | Best Practicable Control Technology Currently Available | high |
| #D021 | | NSPS | New Source Performance Standards | high |
| #D022 | | NPDES | National Pollutant Discharge Elimination System | high |
| #D023 | | NAICS | North American Industrial Classification System | high |
| #D024 | | BPT | Best Practicable Control Technology Currently Available | high |
| #D025 | | NSPS | New Source Performance Standards | high |
| #D026 | | Green Infrastructure (GI) | natural and human-made elements that provide ecological and hydrological functions and processes while also delivering multiple co-benefits. Green infrastructure may include components such as natural heritage features and systems, parklands, stormwater management systems, street trees, urban forests, natural channels, permeable surfaces, and green roofs. | high |
| #D027 | | New Construction | new greenfield or brownfield development. | high |
| #D028 | | Reconstruction | projects with road realignment and resurfacing, projects with adjustments within the right-of-way that would enable installation of GI, or GI-focused projects where the intent is to specifically add GI to an existing streetscape, even if no other work is ongoing. | high |
| #D029 | | Infiltration systems | designed to allow collected rainwater and runoff to return to the natural hydrological cycle by infiltrating into the subgrade. | high |
| #D030 | | Detention systems | sometimes referred to as slow-release systems, are designed to collect rainwater and runoff and return it to the City stormwater sewer network albeit at a reduced flow rate and over an extended period to avoid coinciding with the peak stormwater flows experienced within the receiving network. | high |
| #D031 | | co-benefit | an additional benefit that is achieved by the project when a green infrastructure system is installed. | high |
| #D032 | | clearway | the area must be kept free of sidewalk signs, patios, mailboxes, street furniture, and GI if installed within the boulevard. | high |
| #D033 | | Contributing Drainage Area (CDA) | the physical area that the GI system services. | high |
| #D034 | | Continuous Soil Trench (CST) | a structure designed and built to contain an adequate volume of continuous growing media to support tree growth to maturity under a paved boulevard. | high |
| #D035 | | Stormwater Tree Trench (STT) | A CST that is purposefully designed and constructed to capture, infiltrate and filter stormwater runoff from a drainage area beyond the footprint of the trench. | high |
| #D036 | | Bioretention Systems | purposed to temporarily store stormwater runoff, provide filtration through designated filter media, and infiltration into the underlying native soil. They are typically designed as a shallow, depressed planting bed or similar concrete structure to store captured runoff from minor storm events. | high |
| #D037 | | Bioswales | consists of linear vegetated channels which convey, treat and attenuate stormwater runoff. The subsurface composition of the system consists of a filter media, storage gallery, and optional underdrain dependent upon native soil infiltration rates. | high |
| #D038 | | Boulevard | That part of the public street that is not used, or intended to be used, for vehicle travel by the general public, and that is situated between the travelled portion of the road and the adjoining property line. | high |
| #D039 | | Chicago Storm | a design storm event that corresponds to parameters determined based on Intensity Duration Frequency (IDF) curve relationships. | high |
| #D040 | | SUE | subsurface utility engineering which involves the mapping of underground utilities. | high |