A Brief Summary of the Federal Standards for
Land Application of Sewage Sludge
Ellen Z. Harrison
Cornell Waste Management Institute
Department of Crop & Soil Sciences, Cornell University
Ithaca, NY 14853 ~ 607/255-1187 ~ email@example.com
Environmental Protection Agency adopted regulations in 1993 (40 CFR Part 503,
known as Part 503) that establish minimum standards which must be met if sewage
sludges are to be land applied. The
regulations include concentration limits for 9 metals and for pathogens, and
requirements for vector (flies and rodents) attraction reduction.
regulations establish standards for 9 contaminants (Table 1). The standards include “exceptional quality”
(EQ) sludges which meet certain concentration limits (no more than X parts per
million of any of the 9 regulated contaminants) as well as pathogen limits and
vector reduction requirements. In
regard to metal concentrations, sludges and sludge products which fail to meet
one or more of those “EQ” pollutant concentrations but which fall below a
higher ceiling concentration may be applied, but the agricultural applicator is
directed to keep track of the total amount of each metal applied and cease
application when a regulatory cumulative pollutant loading limit is reached.
treatment is addressed in the rules.
The regulations establish Class A sludges which have been treated to
“essentially eliminate pathogens” (disease causing organisms) and Class B in
which pathogens have been reduced, but are still present in significant
numbers. Under the 503 rules, sludges
and sludge products meeting Class A and “EQ” standards can be applied without
restriction in amount or duration, for use in home gardens, parks, crop production,
etc. There are no requirements for
labeling or for recording or notification of where and how much is used. Under the federal rules pertaining to the
application of Class B sludges or sludges not meeting “EQ” limits but falling
below the ceiling limits, certain restrictions concerning cumulative loading of
contaminants and site access restrictions apply, but no individual site permits
are required for land application.
Sludge products which fail to meet one or more of the “EQ” pollutant
concentrations, but which meet Class A pathogen and vector reduction
requirements and fall below the ceiling concentrations for contaminants, may
also be distributed to homes or in bags so long as information on the
acceptable annual pollutant loading rate (APLR) is provided to the user.
assessment was performed to establish the US EPA limits and to determine what
contaminants to address (Table 2).
Since the regulations were adopted in 1993, the list of regulated
contaminants has been decreased with the elimination of chromium. A list of 31 additional contaminants were
being considered for regulation in “Round 2,” but it is likely that only
co-planar PCBs and dioxins and furans to the list of 9 regulated contaminants in
the next several years.
regulations must be at least as strict as the federal standards, but states
have the option of adopting regulations that are more stringent than the
federal standards. Land application
must follow the more stringent state rules where they exist.
1. Pollutant Limits In US EPA Part 503 Regulations
2. Exposure Pathways Used In the Part 503 Risk Assessment