Code of Colorado Regulations
1000 - Department of Public Health and Environment
1002 - Water Quality Control Commission (1002 Series)
5 CCR 1002-64 - REGULATION NO. 64 - BIOSOLIDS REGULATION
Section 5 CCR 1002-64.12 - CLASSIFICATION AND USE OF BIOSOLIDS
Universal Citation: 5 CO Code Regs 1002-64 ยง 12
Current through Register Vol. 47, No. 17, September 10, 2024
A. Metals Based Classification of Biosolids.
(1) Criteria for metals based classification
of biosolids shall be as defined in Table 1 and Table 3. Determination of
compliance with Table 1 or Table 3 criteria shall be demonstrated by analysis
of the final product material for all of the parameters identified in Table 1
and Table 3. Biosolids classified as Table 1 - Ceiling Concentration Limits
-are subject to the Cumulative Pollutant Loading Rates outlined in Table 2
below:
Table 1 - Ceiling Concentration Limits
|
Pollutant |
mg/kg, dry weight basis |
|
Arsenic |
75 |
|
Cadmium |
85 |
|
Copper |
4300 |
|
Lead |
840 |
|
Mercury |
57 |
|
Molybdenum |
75 |
|
Nickel |
420 |
|
Selenium |
1001 |
|
Zinc |
7500 |
Table 2 - Cumulative Pollutant Loading Rates
|
Pollutant |
kg/ha (lbs/ac) |
|
Arsenic |
41 (37) |
|
Cadmium |
39 (35) |
|
Copper |
1500 (1339) |
|
Lead |
300 (286) |
|
Mercury |
17 (17) |
|
Molybdenum |
|
|
Nickel |
420 (375) |
|
Selenium |
100 (89) |
|
Zinc |
2800 (2499) |
Table 3 - Pollutant Concentration Limits
|
Pollutant |
mg/kg, dry weight basis |
|
Arsenic |
41 |
|
Cadmium |
39 |
|
Copper |
1500 |
|
Lead |
300 |
|
Mercury |
17 |
|
Molybdenum |
|
|
Nickel |
420 |
|
Selenium |
100 |
|
Zinc |
2800 |
1 As a result of a ruling by the United States Court of Appeals for the District of Columbia Circuit on March 3, 1998, the selenium limit set forth in Table 1 is stayed with respect to the City of Pueblo's land application of biosolids at public contact sites with low potential for child occupancy.
(2) Biosolids which exceed the numeric
criteria for Table 1 biosolids shall not be applied to land for beneficial use
except as may be allowed pursuant to the Colorado Solid Waste
Disposal Sites and Facilities Regulations.
(3) Compliance with the numeric criteria
contained in Table 1 or Table 3 shall be determined as follows:
(a) The arithmetic average of all samples
collected within a given calendar month and analyzed for a given parameter
shall not exceed the numeric limit for Table 3 biosolids for any parameter if
the biosolids are to be considered to be within Table 3 Pollutant Concentration
Limits (PC).
(b) The concentration
for any given parameter for which criteria are identified shall not exceed the
numeric limit for Table 1 biosolids in any sample if the biosolids are to be
considered below Table 1 Ceiling Concentration Limits.
(c) The initial determination of biosolids
grade shall be as demonstrated by the arithmetic average of no less than three
composite biosolids samples.
(d)
For reclassification of Table 1 quality as Table 3 quality biosolids compliance
with the Table 3 criteria shall be demonstrated by the arithmetic average of no
less than seven daily composite biosolids samples.
(e) For reclassification of biosolids which
had previously exceeded the Table 1 numeric criteria, compliance with the Table
1 criteria shall be demonstrated by the arithmetic average of no less than
seven daily composite biosolids samples.
(f) All sampling of biosolids for the purpose
of demonstrating compliance with the criteria contained in Table 1 or Table 3
shall be performed in accordance with the requirements of section
64.16(A)(6).
(g) If at any time the
arithmetic average of all samples collected within a given calendar month and
analyzed for a given parameter exceeds the Table 3 Pollutant Concentration
Limits, the biosolids shall no longer be considered within Table 3 Limits and
all applicable requirements for Table 1 biosolids, or the requirements of
paragraph 64.12(A)(2) shall apply. Reclassification of such biosolids shall be
in accordance with the requirements of 64.12(A)(3)(d) above.
(h) If at any time the concentration for any
given parameter for which numeric criteria are identified exceeds the Table 1
Ceiling Concentration Limits, the biosolids shall no longer be considered
within Table 1 limits and the requirements of paragraph 64.12(A)(2) shall
apply. Reclassification of such biosolids shall be in accordance with the
requirements of 64.12(A)(3)(e) above.
B. Pathogen Destruction Criteria.
(1) The requirement in
paragraph (2) of this section and the requirements of any one of paragraphs (3)
through (7) of this section shall be met for biosolids to be classified as
Class A with respect to pathogens.
(2) The Class A pathogen requirements in
paragraphs (3) through (7) shall be met either prior to meeting or at the same
time the vector attraction reduction requirements in section 64.12 are met,
except in those instances when the vector attraction reduction requirements in
paragraphs 64.12(C)(11) through 64.12(C)(13), are those which are
met.
(3) Class A - Alternative 1
(a) Either the density of fecal coliform in
the biosolids shall be less than 1000 Most Probable Number per gram of total
solids (dry weight basis), or the density of
Salmonella sp. bacteria in the biosolids shall be less
than three Most Probable Number per four grams of total solids (dry weight
basis) at the time the biosolids are used or distributed; or at the time the
final product material derived from biosolids is prepared to meet the
requirements in section 64.14 of these regulations, and
(b) The temperature of the biosolids that is
used or distributed shall be maintained at a specific value for a period of
time as determined using the following procedures:
(i) When the percent solids of the biosolids
is seven percent or higher, the temperature of the biosolids shall be 50
degrees Celsius or higher; the time period shall be 20 minutes or longer; and
the temperature and time period shall be determined using the following
equation, except when small particles of biosolids are heated by either warmed
gases or an immiscible liquid.
(ii) When
the percent solids of the biosolids is seven percent or higher and small
particles of biosolids are heated by either warmed gases or an immiscible
liquid, the temperature of the biosolids shall be 50 degrees Celsius or higher;
the time period shall be 15 seconds or longer; and the temperature and time
period shall be determined using the equation specified in paragraph (3)(b)(i)
of this section.
(iii) When the
percent solids of the biosolids is less than seven percent and the time period
is at least 15 seconds, but less than 30 minutes, the temperature and time
period shall be determined using the equation specified in paragraph (3)(b)(i)f
this section.
(iv) When the percent
solids of the biosolids is less than seven percent; the temperature of the
biosolids is 50 degrees Celsius or higher; and the time period is 30 minutes or
longer, the temperature and time period shall be determined using the following
equation:
(4) Class A - Alternative 2
(a) Either the density of fecal coliform in
the biosolids shall be less than 1000 Most Probable Number per gram of total
solids (dry weight basis), or the density of
Salmonella sp. bacteria in the biosolids shall be less
than three Most Probable Number per four grams of total solids (dry weight
basis) at the time the biosolids are used or distributed, and
(b) at the time the final product material
derived from biosolids is prepared to meet the requirements in section 64.14 of
these regulations
(i) the pH of the biosolids
that is used or distributed shall be raised to above 12 s.u. and shall remain
above 12 s.u. for 72 hours, and
(ii) the temperature of the biosolids shall
be above 52 degrees Celsius for 12 hours or longer during the period that the
pH of the biosolids is above 12 s.u., and
(iii) at the end of the 72-hour period during
which the pH of the biosolids is above 12 s.u., the biosolids shall be air
dried to achieve a percent solids in the biosolids of greater than 50
percent.
(5)
Class A - Alternative 3
(a) Either the density
of fecal coliform in the biosolids shall be less than 1000 Most Probable Number
per gram of total solids (dry weight basis), or the density of
Salmonella sp. bacteria in biosolids shall be less
than three Most Probable Number per four grams of total solids (dry weight
basis), at the time the biosolids are used or distributed; or at the time the
final product material derived from biosolids is prepared to meet the
requirements in section 64.14 of these regulations, and
(b) the biosolids shall be analyzed prior to
pathogen treatment to determine whether the biosolids contains enteric viruses.
(i) When the density of enteric viruses in
the biosolids prior to pathogen treatment is less than one Plaque-forming Unit
per four grams of total solids (dry weight basis), the biosolids is considered
Class A with respect to enteric viruses until the next monitoring episode for
the biosolids.
(ii) When the
density of enteric viruses in the biosolids prior to pathogen treatment is
equal to or greater than one Plaque-forming Unit per four grams of total solids
(dry weight basis), the biosolids is considered Class A with respect to enteric
viruses when the density of enteric viruses in the biosolids after pathogen
treatment is less than one Plaque-forming Unit per four grams of total solids
(dry weight basis) and when the values or ranges of values for the operating
parameters for the pathogen treatment process that produces the biosolids that
meets the enteric virus density requirement are documented.
(iii) After the enteric virus reduction in
paragraph (ii) of this subsection is demonstrated for the pathogen treatment
process, the biosolids continues to be considered Class A with respect to
enteric viruses when the values for the pathogen treatment process operating
parameters are consistent with the values or ranges of values documented in
paragraph (ii) of this subsection.
(c) The biosolids shall be analyzed prior to
pathogen treatment to determine whether the sewage sludge contains viable
helminth ova.
(i) When the density of viable
helminth ova in the biosolids prior to pathogen treatment is less than one per
four grams of total solids (dry weight basis), the biosolids is considered
Class A with respect to viable helminth ova until the next monitoring episode
for the biosolids.
(ii) When the
density of viable helminth ova in the biosolids prior to pathogen treatment is
equal to or greater than one per four grams of total solids (dry weight basis),
the biosolids is considered Class A with respect to viable helminth ova when
the density of viable helminth ova in the biosolids after pathogen treatment is
less than one per four grams of total solids (dry weight basis) and when the
values or ranges of values for the operating parameters for the pathogen
treatment process that produces the biosolids that meets the viable helminth
ova density requirement are documented.
(iii) After the viable helminth ova reduction
in paragraph (ii) of this subsection is demonstrated for the pathogen treatment
process, the biosolids continue to be considered Class A with respect to viable
helminth ova when the values for the pathogen treatment process operating
parameters are consistent with the values or ranges of values documented in
(ii) of this subsection.
(6) Class A - Alternative 4
(a) Either the density of fecal coliform in
the biosolids shall be less than 1000 Most Probable Number per gram of total
solids (dry weight basis) or the density of Salmonella
sp. bacteria in the biosolids shall be less than three Most Probable Number per
four grams of total solids (dry weight basis) at the time the biosolids are
used or distributed; or at the time the final product material derived from
biosolids is prepared to meet the requirements in section 64.14 of these
regulations, and
(i) The density of enteric
viruses in the biosolids shall be less than one Plaque-forming Unit per four
grams of total solids (dry weight basis) at the time the biosolids are used or
distributed; or at the time the final product material derived from biosolids
is prepared to meet the requirements in section 64.14 of these regulations, and
(ii) the density of viable
helminth ova in the biosolids shall be less than one per four grams of total
solids (dry weight basis) at the time the biosolids are used or distributed; or
at the time the final product material derived from biosolids is prepared to
meet the requirements in section 64.14 of these regulations.
(7) Class A -
Alternative 5
(a) Either the density of fecal
coliform in the biosolids shall be less than 1000 Most Probable Number per gram
of total solids (dry weight basis) or the density of
Salmonella, sp. bacteria in the biosolids shall be
less than three Most Probable Number per four grams of total solids (dry weight
basis) at the time the biosolids are used or distributed; or at the time the
final product material derived from biosolids is prepared to meet the
requirements in section 64.14 of these regulations, and
(b) Biosolids that are used or distributed
shall be treated in one of the Processes to Further Reduce Pathogens described
as follows:
(i) Composting - Using either the
within-vessel composting method or the static aerated pile composting method,
the temperature of the biosolids compost is maintained at 55 degrees Celsius or
higher for three days.
Using the windrow composting method, the temperature of the biosolids compost is maintained at 55 degrees or higher for 15 days or longer. During the period when the compost is maintained at 55 degrees or higher, there shall be a minimum of five turnings of the windrow.
(ii) Heat drying - Biosolids are dried by
direct or indirect contact with hot gases to reduce the moisture content of the
biosolids to 10 percent or lower. Either the temperature of the biosolids
particles exceeds 80 degrees Celsius or the wet bulb temperature of the gas in
contact with the biosolids as the biosolids leaves the dryer exceeds 80 degrees
Celsius.
(iii) Heat treatment -
Liquid biosolids are heated to a temperature of 180 degrees Celsius or higher
for 30 minutes.
(iv) Thermophilic
aerobic digestion - Liquid biosolids are agitated with air or oxygen to
maintain aerobic conditions and the mean cell residence time of the biosolids
is 10 days at 55 to 60 degrees Celsius.
(v) Beta ray irradiation - Biosolids are
irradiated with beta rays from an accelerator at dosages of at least 1.0
megarad at room temperature (ca. 20 degrees Celsius).
(vi) Gamma ray irradiation - Biosolids are
irradiated with gamma rays from certain isotopes, such as Cobalt 60 and Cesium
137, at room temperature (ca. 20 degrees Celsius).
(vii) Pasteurization - The temperature of the
biosolids is maintained at 70 degrees Celsius or higher for 30 minutes or
longer.
(viii) Any other method of
biosolids treatment which is certified as a Process to Further Reduce Pathogens
by the U. S. Environmental Protection Agency, Region VIII, or, after assumption
of delegation by the State, which is certified as such by the
Division.
(8)
The requirement in either of paragraphs (a), or (b) of this subsection shall be
met for biosolids to be classified as Class B with respect to pathogens.
(a) Seven individual samples of the biosolids
shall be collected at the time the biosolids are used or distributed or at the
time the final product material derived from biosolids is prepared to meet the
requirements in section 64.15 of these regulations. The geometric mean of the
density of fecal coliform in the samples collected shall be less than either
2,000,000 Most Probable Number per gram of total solids (dry weight basis) or
2,000,000 Colony Forming Units per gram of total solids (dry weight basis),
or
(b) Biosolids that are used or
distributed shall be treated in one of the Processes to Significantly Reduce
Pathogens described as follows:
(i) Aerobic
digestion - Biosolids are agitated with air or oxygen to maintain aerobic
conditions for a mean cell residence time at a temperature or temperatures
within a time-temperature function having as end points 40 days at 20 degrees
Celsius and no less than 60 days at 15 degrees Celsius.
(ii) Air drying - Biosolids are dried on sand
beds or on paved or unpaved basins. The biosolids dries for a minimum of three
months. During two of the three months, the ambient average daily temperature
is above zero degrees Celsius.
(iii) Anaerobic digestion - Biosolids are
treated in the absence of air for a mean cell residence time at a temperature
or temperatures within a time-temperature function having as end points 15 days
at 35 to 55 degrees Celsius and no less than 60 days at 20 degrees
Celsius.
(iv) Composting - Using
either the within-vessel, static aerated pile, or windrow composting methods,
the temperature of the biosolids is raised to 40 degrees Celsius or higher and
remains at 40 degrees Celsius or higher for five days. For four hours during
the five days, the temperature in the compost pile exceeds 55 degrees
Celsius.
(v) Lime stabilization -
Sufficient lime is added to the biosolids to raise the pH of the sewage sludge
to 12 after two hours of contact.
(vi) Any other method of biosolids treatment
which is certified as a Process to Significantly Reduce Pathogens by the U. S.
Environmental Protection Agency, Region VIII, or, after assumption of
delegation by the State, which is certified as such by the Division.
(9) The site
restrictions in section 64.15 of these regulations shall be met when biosolids
that meets the Class B pathogen requirements in paragraphs (8)(a) or (8)(b) of
this subsection is applied to the land.
C. Vector Attraction Reduction (Biosolids Stability) Criteria.
(1) One of the biosolids stability
requirements in paragraphs (3) through (13) shall be met when biosolids are
applied to agricultural or disturbed land, or to a public contact
site.
(2) One of the biosolids
stability requirements in paragraphs (3) through (10) shall be met when
biosolids are distributed to the public for use.
(3) The mass of volatile solids in the
biosolids shall be reduced by a minimum of 38 percent.
(4) When the 38 percent volatile solids
reduction requirement in paragraph (3) cannot be met for anaerobically digested
biosolids, biosolids stability can be demonstrated by digesting a portion of
the previously digested biosolids anaerobically in the laboratory in a
bench-scale unit for 40 additional days at a temperature between 30 and 37
degrees Celsius. When at the end of the 40 days, the volatile solids in the
biosolids at the beginning of that period is reduced by less than 17 percent,
biosolids stability is achieved.
(5) When the 38 percent volatile solids
reduction requirement in paragraph (3) cannot be met for aerobically digested
biosolids, biosolids stability can be demonstrated by digesting a portion of
the previously digested biosolids that has a percent solids of two percent or
less aerobically in the laboratory in a bench-scale unit for 30 additional days
at 20 degrees Celsius. When at the end of the 30 days, the volatile solids in
the biosolids at the beginning of that period is reduced by less than 15
percent, biosolids stability is achieved.
(6) The specific oxygen uptake rate (SOUR)
for biosolids treated in an aerobic process shall be equal to or less than 1.5
milligrams of oxygen per hour per gram of total solids (dry weight basis) at a
temperature of 20 degrees Celsius.
(7) Biosolids shall be treated in an aerobic
process for 14 days or longer. During that time, the temperature of the
biosolids shall be higher than 40 degrees Celsius and the average temperature
of the biosolids shall be higher than 45 degrees Celsius.
(8) The pH of biosolids shall be raised to 12
or higher by alkaline addition and, without the addition of more alkaline
material, shall remain at 12 or higher for two hours and then at 11.5 or higher
for an additional 22 hours.
(9) The
percent solids of biosolids that does not contain unstabilized solids generated
in a primary wastewater treatment process shall be equal to or greater than 75
percent based on the moisture content and total solids prior to mixing with
other materials.
(10) The percent
solids of biosolids that contains unstabilized solids generated in a primary
wastewater treatment process shall be equal to or greater than 90 percent based
on the moisture content and total solids prior to mixing with other
materials.
(11) Biosolids shall be
subsurface injected, and
(a) No significant
amount of the biosolids shall be present on the land surface within one hour
after the biosolids are injected.
(b) When the biosolids which are subsurface
injected are considered to be Class A with respect to pathogens, the biosolids
shall be injected within eight hours after being discharged from the pathogen
treatment process.
(12)
Biosolids which are surface applied shall be incorporated into the soil within
six hours after application to or placement on the land.
(13) When biosolids that are incorporated
into the soil are considered to be Class A with respect to pathogens, the
biosolids shall be applied to or placed on the land within eight hours after
being discharged from the pathogen treatment process.
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