Geologic, Hydrologic, and Urban Hazards for Design in Desert Environments - Design with the Desert: Conservation and Sustainable Development - page 107

wastes from hardrock mining—especially the mining of metallic ores and phosphates—
and 20 specific mineral processing wastes are categorized by EPA as “special wastes”
and have been exempted by the Mining Waste Exclusion from federal hazardous waste
regulations under Subtitle C of the RCRA.* This distinction is important to understand
when redevelopment of sites affected by these types of mining.
5.7.3 Hazardous Wastes
Hazardous wastes are defined by the RCRA as materials that exhibit characteristics such
as ignitability, corrosivity, reactivity, and toxicity; are included on the EPA list; or are
spent materials or other inherently waste like material that affects human health and
environment when disposed improperly. † Hazardous wastes are regulated by RCRA and it
follows the concept of cradle-to-grave management. The act covers not only the generator
of hazardous wastes but also the transporter and the disposal facility. The generators
are classified as large quantity generator (LQG), small quantity generator (SQG), and
conditionally exempt small quantity generator (CESQG), depending on the amount of
hazardous wastes generated and or stored onsite prior to offsite disposal.
CESQGs generate no more than 220 lb of hazardous waste in any month. CESQGS
are exempt from hazardous-waste management regulations, provided that certain basic
requirements are met. SQGs generate between 220 and 2200 lb of hazardous waste in any
month, while LQGs generate more than 2200 lb of hazardous waste per month. LQGs
must comply with more extensive hazardous waste rules, particularly with some wastes
that are considered to be so dangerous that they are called acutely hazardous wastes. If
a business generates or accumulates more than 2.2 lb of acutely hazardous waste in a
calendar month, all of the acutely hazardous waste must be managed according to the
regulations applicable to LQGs. ‡ In 2007 alone, Arizona generated 54,091 tons of RCRA
wastes from 175 generators, California generated 608,654 tons of RCRA wastes from 2,312
generators, and Nevada generated 10,041 tons of RCRA wastes from 73 generators. §
Both SQGs and LQGs of hazardous waste are required to have an EPA ID number for their
waste-generation facilities. LQGs are required to have waste minimization and pollution
prevention plans to reduce the amount of hazardous waste generated. Annual reports and
audits are also required under RCRA. Using an RCRAInfo query, ¶ Arizona, California,
Arizona, and Nevada have more than 11,000, 8,455, and 4,148 facilities, respectively, in
2010. This database includes small and large quantity generators of hazardous wastes,
transporters of hazardous wastes, and treatment storage and disposal facilities. Large-scale
agricultural and meat processing operations add to the contamination of the water and
soil because discharges and runoff from these operations contain pesticides, insecticides,
fertilizers, and animal wastes. In spite of CWA regulations and discharge restrictions, off-
site contamination and pollution that affect natural and urban environments continue and
are factors affecting urban design locally.
Department of Defense (DOD) facilities are a major source of pollution, and closure of
bases offers the opportunity for redevelopment and the problem of mitigation of wastes
and pollution. A 1992 hazardous waste survey by DOD 51 revealed that 59 of the nation's
* http://www.epa.gov/compliance/civil/rcra/rcraenfstatreq.html (accessed June 25, 2010).
† 40 CFR Part 261, Hazardous waste identification and listing, Subparts C and D; http://www.epa.gov/wastes/
inforesources/pubs/hotline/training/hwid05.pdf (accessed June 28, 2010).
‡ http://www.epa.gov/waste/inforesources/online/index.htm (accessed June 25, 2010).
§ http://www.epa.gov/waste/inforesources/data/br07/state07.pdf (accessed June 25, 2010).
¶ http://www.epa.gov/enviro/html/rcris/ (accessed June 23, 2010).