 |
|
 |
| 
Biosolids Regulations
Missouri state rules for biosolids land application were
first created in 1982 followed by federal rules issued in
1993 by the EPA (40 CFR Part 503). The combination of these
regulations works to ensure the safety of this practice to
human and environmental health. Biosolids generated at the
Southwest and Northwest Treatment Plants meet Class B pathogen
control standards. Class B biosolids have undergone treatment
to reduce pathogens. Site restrictions and management practices,
including minimum time durations between application and land
usage, allow natural processes to further reduce pathogen
levels. Class B guidelines also restrict the types of cropland
on which these biosolids can be applied. Locally, the biosolids
are applied to lands producing animal feed crops such as fescue
and millet. The EPA has designated 10 pollutants for regulation
based on risk analysis studies of the composition of a national
sampling of sewage sludge. These regulatory limits along with
average detected levels in locally generated biosolids are
shown in Table 1.
The City of Springfield’s Industrial
Pretreatment Program helps to meet these limits by reducing
the amount of pollutants in the wastewater before it is discharged
to the treatment plant. Additionally, regulations include
reducing the attraction of vectors such as rodents and flies
through treatment or application options, and calculating
application levels not to exceed the agronomic rate of nitrogen.
Table 2 shows the
nitrogen content of local biosolids. Monitoring, record keeping,
and reporting requirements must also be fulfilled.
To ensure protection of the area's bountiful and scenic waterways,
the Missouri Department of Natural Resources requires compliance
with additional guidelines beyond EPA regulations. These guidelines
include increased buffer zones around wells and waterways,
and phosphorus restrictions.
|
Do biosolids contain pollutants?
Biosolids can contain organic and inorganic pollutants other
than the current regulated list shown in Table 2. This list
is the result of the first of two rounds of evaluation by
the EPA of pollutants to consider for regulation. The Round
1 evaluation began with 411 pollutants on which data was collected
in a National Sewage Sludge Survey (NSSS) in 1990. The list
was narrowed down based on a set of criteria for exemption
from regulation. Round 2 was conducted in 1996 and started
with the same list of 411 pollutants. Initial screening narrowed
the list to thirty by eliminating pollutants that were not
detected in the NSSS, detected in less than 10% of samples
from the NSSS, and that lacked sufficient toxicity data. Further
hazard identification studies eliminated all pollutants but
dioxins, furans, and coplanar PCB’s from consideration
for regulation. A proposed limit and monitoring requirements
for these compounds, considered collectively as “dioxins”,
in biosolids applied to land was issued in 1999 by the EPA
for peer review. The proposal has yet to be mandated due to
continuing evaluation and debate on the subject. See biosolids
news for more information. |
|
Are biosolids safe?
The current EPA and state regulations are based on extensive
studies of the possible long-term effects of the land application
of biosolids. However, studies are ongoing and the City of
Springfield will implement any new guidelines as required.
Any questions or comments about the environmental and health
concerns of biosolids usage are welcome and can be directed
to Ed Malter, Superintendent of Sanitary Services, at 891-1600.
The following links may also provide helpful information.
|
Biosolids News:
• In July 2002 the National Research Council (NRC)
released its report, Biosolids Applied to Land: Advancing
Standards and Practices. This report was commissioned
by the EPA in response to an audit by the EPA's Office of
Inspector General. While the audit did not find evidence that
the existing Part 503 reglulations were not protective of
public health, it was concluded that further attention on
the subject of biosolids land application was needed.The report
reviews the science and methodology behind the current EPA
Part 503 regulations.
• In June 2002 the EPA published a Notice of Data Availability
(NODA) relating to the standard proposed in 1999 for dioxins
in biosolids applied to land. The NODA summarizes new data
and a revised risk assessment gathered since the proposal
was made and includes a request for public comments on the
new data and on the proposal. The EPA is required to make
a final decision on the proposed standard for dioxins by October
17, 2003.
Top |
| |
| |
Regulations