Section 391.420 Heavy Metal Loading

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.