Increased regulatory scrutiny has created a big market for treatment of wastewater being discharged directly to receiving streams rather than to municipal treatment plants by more than 90,000 facilities in the U.S. These facilities in general have large enough flows to justify the investment in treatment equipment rather than pay municipalities for this service. The McIlvaine Company has compiled rankings of these facilities by number within each industry category and included this display in an online database: U.S. Industrial Facilities With Water Discharges.
The heavy construction industry heads the list with just under 4,000 facilities. This does not include 2,000 ready mixed concrete plants and another 1,800 crushed and broken limestone plants. It does not include 1,700 sand and gravel plants. 1,854 power plants are direct dischargers. But this is equaled by the number of gold mines. 1,200 bituminous and lignite coal operations are also included.
The food and related industries are significant discharges. Here are the totals for the largest categories:
Category # of plants
- Dairy farms 688
- Chicken processing 514
- Cattle lots 506
- Fish hatcheries 497
- Hogs 398
- Seafood 364
- Poultry and eggs 233
- Poultry processing 190
- Milk 78
- Wet corn milling 47
These facilities are subject to existing and proposed discharge rules. EPA finalized a rule June 30 to reduce discharges from farm-raised fish facilities that generate wastewater and discharge it directly into U.S. waters. The rule will reduce annual discharges of suspended solids by more than 500,000 pounds and also will reduce the amount of toxic pollutants at 245 facilities that produce at least 100,000 pounds of fish per year and discharge at least 30 days per year.
The chemical industry is another segment with large numbers of direct dischargers. Included are:
Category # of plants
- Industrial organic chemicals 372
- Plastics and synthetic resins 316
- Medicinal chemicals 116
- Pharmaceutical preparations 110
- Paints and varnishes 109
- Nitrogen fertilizers 70
- Cyclic crudes/dyes 70
- Adhesives 61
- Pesticides 59
- Phosphate fertilizers 42
- Soap 37
- Explosives 36
The 90,000 plants include many commercial facilities such as hotels and retail operations. There are also 2,400 gasoline service stations and 1,600 crude oil and gas operations in the database.
Source: McIlvaine Company
