# 35 Ill. Adm. Code 391.420: Section 391.420 Heavy Metal Loading

> Illinois · Regulations · In force

URL: https://www.frixlaw.com/law-library/statutes/STATE_IL_IAC_T35_P391_S391_420

## Section

- **Citation:** 35 Ill. Adm. Code 391.420
- **Heading:** Section 391.420 Heavy Metal Loading
- **Jurisdiction:** Illinois
- **Kind:** Regulations
- **Status:** In force
- **Text as of:** August 14, 2026
- **Source:** Compiled text
- **Location:** Illinois Administrative Code / Title 35 ENVIRONMENTAL PROTECTION / CHAPTER II: ENVIRONMENTAL PROTECTION AGENCY / Part 391 DESIGN CRITERIA FOR SLUDGE APPLICATION ON LAND / Section 391.420 Heavy Metal Loading

## Text

Section 391
Section 391.420   Heavy Metal
Loading
a)         Heavy metal loading rates on sludge application projects are
limited to prevent significant increases of heavy metals in the food chain,
phytotoxicity and water pollution.  Generators shall sample their sludge for
metals in accordance with Subpart E and accordingly limit annual and total
cumulative sludge application rates.
b)         Sites which have a lifetime of sludge application less than 5
years due to metal loading rates in Subsection c below shall be identified in a
permit application.  The Agency shall not issue a permit for sludge application
on such sites unless the following items are considered in the application:
1)         Groundwater monitoring;
2)         Soil monitoring;
3)         Plant tissue sampling and analyses;
4)         Additional operational controls.
c)         Soil cation exchange capacity (CEC) plays a major role in
enabling the soil to retain the heavy metals contained in the sludge.  Soils
having a CEC in the range from 5 to 15 meq/100gm are acceptable for sludge
utilization providing sludge application rates do not result in heavy metals
being applied to land in excess of those amounts listed in Table II below.
TABLE II
MAXIMUM ACCEPTABLE HEAVY
METAL LOADING RATES OVER
THE LIFE OF A PROJECT SITE
(pounds per acre)
Metal
Total
Annual
Pb
1000
–
Mn
900
–
Zn
500
–
Cu
250
–
Ni
100
–
Cd
10
2
d)         There are some areas in Illinois which have low soil CEC (<5
meq/100g) and should be avoided for sludge application whenever possible.  If a
sludge management plan includes sludge application in these areas, the sludge
generator or user shall apply only half of the heavy metal loading rates set
forth in Table II.
e)         Permits may be issued which allow application of double the
amounts listed in Table II providing it is demonstrated that the soil CEC is
greater than 15 meq/100g
for sludge application whenever possible.  If a
sludge management plan includes sludge application in these areas, the sludge
generator or user shall apply only half of the heavy metal loading rates set
forth in Table II.
e)         Permits may be issued which allow application of double the
amounts listed in Table II providing it is demonstrated that the soil CEC is
greater than 15 meq/100g.  However, an extensive soil survey must be performed
prior to and during the sludge application period to demonstrate the
consistency of high soil CEC values at the sludge application site.
f)         The Agency may request an applicant to analyze a sludge for
elements other than those in Table II and to limit sludge application based on
other elements due to potential for groundwater or surface water pollution,
phytotoxicity, mammalian toxicity or other environmental concerns.  If the
Agency determines that metals other than those in Table II should restrict the
proposed application rate, the following loading rates shall be utilized for
the land application project:
TABLE III
ACCEPTABLE LOADING RATES
(pounds per acre)
Metal
Total
Annual
Antimony
700
Arsenic
100
Chromium
(trivalent)
3500
89
Chromium
(hexavalent)
440
44
Mercury
7
Selenium
8
Silver
178
g)         If sludge concentrations of molybdenum and/or selenium exceed
4.0 mg/kg (dry weight basis) the Agency shall restrict the crops to be grown on
land receiving applications of that sludge or shall restrict the use of crops
for livestock forage as necessary to prevent toxicity to livestock
nic
100
Chromium
(trivalent)
3500
89
Chromium
(hexavalent)
440
44
Mercury
7
Selenium
8
Silver
178
g)         If sludge concentrations of molybdenum and/or selenium exceed
4.0 mg/kg (dry weight basis) the Agency shall restrict the crops to be grown on
land receiving applications of that sludge or shall restrict the use of crops
for livestock forage as necessary to prevent toxicity to livestock.
h)         The Agency will consider allowing loading rates greater than
those specified in this Section provided the generator or user addresses the
following items:
1)         Soil testing results with particular attention to plant available
metals and phosphorus;
2)         Groundwater monitoring results and adjacent groundwater use;
3)         Plant tissue sampling and analyses and the ultimate use of the
crop;
4)         Availability of additional application sites;
5)         Hydrogeology of the application site;
6)         Operational constraints of the application site;
7)         Ultimate use of the application site.

## Nearby sections

- [35 Ill. Adm. Code 391.401 Section 391.401  Introduction](https://www.frixlaw.com/law-library/statutes/STATE_IL_IAC_T35_P391_S391_401.md)
- [35 Ill. Adm. Code 391.402 Section 391.402  General Criteria](https://www.frixlaw.com/law-library/statutes/STATE_IL_IAC_T35_P391_S391_402.md)
- [35 Ill. Adm. Code 391.403 Section 391.403  Application Buffer Area](https://www.frixlaw.com/law-library/statutes/STATE_IL_IAC_T35_P391_S391_403.md)
- [35 Ill. Adm. Code 391.404 Section 391.404  Site Characteristics](https://www.frixlaw.com/law-library/statutes/STATE_IL_IAC_T35_P391_S391_404.md)
- [35 Ill. Adm. Code 391.405 Section 391.405  Water Treatment Plant Sludge](https://www.frixlaw.com/law-library/statutes/STATE_IL_IAC_T35_P391_S391_405.md)
- [35 Ill. Adm. Code 391.410 Section 391.410  Nutrient Loading](https://www.frixlaw.com/law-library/statutes/STATE_IL_IAC_T35_P391_S391_410.md)
- [35 Ill. Adm. Code 391.412 Section 391.412  Phosphorus](https://www.frixlaw.com/law-library/statutes/STATE_IL_IAC_T35_P391_S391_412.md)
- [35 Ill. Adm. Code 391.413 Section 391.413  Potassium](https://www.frixlaw.com/law-library/statutes/STATE_IL_IAC_T35_P391_S391_413.md)
- [35 Ill. Adm. Code 391.420 Section 391.420  Heavy Metal Loading](https://www.frixlaw.com/law-library/statutes/STATE_IL_IAC_T35_P391_S391_420.md)
- [35 Ill. Adm. Code 391.430 Section 391.430  Site Monitoring](https://www.frixlaw.com/law-library/statutes/STATE_IL_IAC_T35_P391_S391_430.md)
- [35 Ill. Adm. Code 391.440 Section 391.440  Additional Precautions](https://www.frixlaw.com/law-library/statutes/STATE_IL_IAC_T35_P391_S391_440.md)
- [35 Ill. Adm. Code 391.450 Section 391.450  Land Reclamation Projects](https://www.frixlaw.com/law-library/statutes/STATE_IL_IAC_T35_P391_S391_450.md)

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Source: Frix Law Library, https://www.frixlaw.com/law-library/statutes/STATE_IL_IAC_T35_P391_S391_420. Check the current official text before relying on it. Not legal advice.