Unsafe sewage sludge or beneficial biosolids?: Liability, planning, and management issues regarding the land application of sewage treatment residuals

Boston College Environmental Affairs Law Review, Summer 1999 by Goldfarb, William, Krogmann, Uta

Although land application of sewage sludge can substantially improve land productivity, and also represents a cheap and technologically viable option for many communities, it has limits and risks. Odors are the most annoying problem for neighbors of farmers who apply sewage sludge. In addition, if sewage sludge is improperly handled, pollutants (trace elements or persistent organic chemicals) and pathogens (viruses, bacteria, or parasites) in sewage sludge could potentially contaminate soils, crops, livestock, and even humans.55 For example, successive sewage sludge applications to land can result in an accumulation of heavy metals in the soil. This accumulation can potentially result in soil concentrations of metals that are toxic to plants, soil organisms, animals, and humans along the food chain. In a report assessing the risks of sewage sludge land application, EPA identified fourteen potential exposure pathways resulting from such land application:56

1. Sewage sludge >> Soil >> Plant >> Human (Consumer of plant products)

2. Sewage sludge >> Soil >> Plant >> Human (Home gardener)

3. Sewage sludge >> Human (Child eating sewage sludge)

4. Sewage sludge >> Soil >> Plant >> Animal >> Human

5. Sewage sludge >> Soil >> Animal >> Human (Animals ingest sludge directly)

6. Sewage sludge >> Soil >> Plant >> Animal

7. Sewage sludge >> Soil >> Animal

8. Sewage sludge >> Soil >> Plant

9. Sewage sludge >> Soil >> Soil organism

10. Sewage sludge >> Soil >> Soil organism >> Soil organism predator

11. Sewage sludge >> Soil >> Airborne dust >> Human

12. Sewage sludge >> Soil >> Surface water >> Human

13. Sewage sludge >> Soil >> Air >> Human

14. Sewage sludge >> Soil >> Ground water >> Human

Pathway 3 (a child eating sewage sludge), pathway 6 (an animal over a lifetime of eating plants grown on sludge-applied soil), and pathway 8 (plant phytotoxicity) were considered the most likely pathways in the EPA risk assessment.67

Due to the large number of potential contaminants in sewage sludge and the complexity of the contamination pathways just described, land application of sewage sludge has endured a tortured regulatory history.

II. REGULATORY HISTORY OF SEWAGE SLUDGE

A. pretreatment Problems

The Clean Water Act (CWA), enacted in 1972 and significantly amended in 1977 and 1987, directs EPA to promulgate regulations establishing limits on the types and amounts of pollutants that can be legally discharged from various industrial, commercial, and public dischargers of wastewater.58 Congress recognized that regulating only those sources discharging effluent directly into waterbodies would not achieve the objectives of the CWA. Thus, the CWA also requires EPA to promulgate nationally applicable pretreatment standards, which restrict pollutant discharges from industries that indirectly discharge into waterbodies by discharging into sewers.59 Pretreatment standards are implemented in the first instance by POTWs, with states and EPA performing backup monitoring and enforcement roles. In addition to national pretreatment standards, POTWs are also required to implement more stringent local pretreatment standards applicable to their industrial indirect dischargers where necessary to meet water quality standards.60

An indirect discharger gains a number of advantages from plugging into a POTW. First, because the indirect discharging industry is a customer of the POTW, which is the primary enforcement authority, the indirect discharger can expect more sympathetic monitoring and enforcement from the POTW than would a direct discharger from a state or federal permitting agency.61 Second, the Domestic Sewer Exclusion clause in the federal Resource Conservation and Recovery Act (RCRA) exempts any indirect industrial discharge into a sewer from RCRA's reporting, permitting, and treatment requirements (i.e., such a discharge is not considered a solid waste).62 Third, an indirect discharger is not required to have a National Pollutant Discharge Elimination System Permit (NPDES) under the CWA.63 The agreement between the indirect discharger and the POTW is incorporated into a local permit or contract that is often not subject to public participation or enforcement by citizen suits.64 Finally, indirect discharge is a distinct bargain: