Current through Register Vol. 24-06, March 15, 2024
This section contains the requirements for the land application
of septage as defined in WAC
173-308-080.
This section does not apply to "septage managed as biosolids
originating from sewage sludge" as defined in WAC
173-308-080. Facilities who seek
to manage their septage as biosolids must meet all of the requirements
applicable to the particular classification of biosolids into which it
falls.
(1) Septage applied to the land
must meet the requirements for a significant reduction in manufactured inerts
in WAC 173-308-205.
(2) Septage may not be applied to a public
contact site, a lawn, or a home garden.
(3)
Pathogen reduction and vector
attraction reduction.
(a) For loads of
septage that are composed of at least seventy-five percent by volume of septage
from households, one of the following requirements must be met:
(i) The septage must be injected below the
surface of the land and no significant amount of septage may be present on the
land surface within one hour after the septage is injected.
(ii) Septage must be incorporated into the
soil within six hours after application to the land.
(iii) The pH of the septage must be raised to
twelve or higher and must remain at twelve or higher for a minimum of thirty
minutes.
(A) A minimum of two tests for pH
must be conducted for each load applied to the land.
(B) The first test must occur after a pH of
twelve or higher has been attained.
(C) The second test must occur no less than
thirty minutes after the first test to show that a pH of twelve or higher has
been retained.
(D) If the pH has
dropped below twelve when the second test is conducted, the stabilization
process must be restarted.
(b) For loads of septage not composed of at
least seventy-five percent by volume of septage from households, the
requirements in (a)(iii) of this subsection must be met.
(4)
Site management and access
restrictions. All of the following site management and access
restrictions are applicable when septage is applied to the land:
(a) Food crops, feed crops, and fiber crops
must not be harvested for thirty days after the application of
septage.
(b) Food crops with
harvested parts that touch the septage/soil mixture and are totally above the
land surface must not be harvested for a minimum of fourteen months after the
last application of septage.
(c)
Food crops with harvested parts below the surface of the land must not be
harvested for a minimum of twenty months after the last application of septage
when the septage remains on the land surface for four months or longer prior to
incorporation into the soil.
(d)
Food crops with harvested parts below the surface of the land must not be
harvested for a minimum of thirty-eight months after the last application of
septage when the septage remains on the land surface for less than four months
prior to incorporation into the soil.
(e) Septage must not be applied to land that
is one hundred feet (30.5 meters) or less from surface waters of the state,
unless otherwise specified by the department.
(f) Septage must not be applied to the land
so that it enters a wetland or waters of the state, unless approved in a permit
issued by the department, or by EPA with the approval of the
department.
(g) Septage must not be
applied to the land within one hundred feet (30.5 meters) of a well unless
approved in a permit issued by the department.
(h) Domestic animals must not be allowed to
graze on the land for a minimum of thirty days after the last application of
septage.
(i) Public access to land
with a high potential for public exposure must be restricted for a minimum of
one year after the last application of septage.
(j) Public access to land with a low
potential for public exposure must be restricted for a minimum of thirty days
after the last application of septage.
(k) During the time when access is
restricted, signs must be posted around the application site at all significant
points of access and at least every 1/2 mile (805 meters) around the perimeter
of the site. Unless the department has approved the substitution of "no
trespassing" signs for informational signs, signs must contain at least the
following:
(i) The name and address or phone
number of the generator and if different, the person who applies.
(ii) The names, addresses, and phone numbers
of the regulatory and permitting authorities.
(iii) The material that is being applied
(septage or a more detailed description).
(iv) Notice that access is restricted, and if
desired, the date after which access is no longer restricted.
(v) If applicable, a notice on limitations
regarding the harvest of edible plants from the site.
It is a violation of these rules for any person to remove a
sign posted in accordance with the requirements of this subsection during the
period when access is restricted.
(5)
Application rates.
(a) Septage that is applied to the land must
be applied at a rate not exceeding the rate determined by equation
(3).
(b) At its discretion, the
department may require the use of a different approach for calculating
application rates based on the mixture ratios and site specific criteria, but
at no time may the rate exceed that calculated by equation (3).
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Equation (3)
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AAR
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=
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N
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0.0026
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Where:
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AAR = Annual application rate in gallons per acre per
365-day period.
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N = Amount of nitrogen in pounds per acre per 365-day
period needed by the crop or vegetation grown on the land (subtract any
nitrogen supplied by other sources - for example, commercial fertilizers or
manures).
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(6)
Spreader drive length. To
determine the distance (in feet) over which a load of liquid septage should be
spread to meet the application rate, use equation (4).
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Equation (4)
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Drive length (in feet) = gallons in spreader / spread
width (in feet) x 43,560 / AAR
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Where:
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AAR = Annual application rate in gallons per acre per
365-day period.
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(7)
Monitoring.
(a) Samples of
septage that are collected and analyzed must be representative of the septage
that is applied to the land.
(b)
When septage is applied to the land and pH adjustment as described in
subsection (3)(a)(iii) of this section is used to meet the pathogen and vector
attraction reduction requirements, each container of septage that is applied to
the land must be monitored to determine compliance with the pH
requirements.
Statutory Authority: Chapters 70.95J and
70.95 RCW. 07-12-010 (Order 06-06),
§ 173-308-270, filed 5/24/07, effective 6/24/07. Statutory Authority:
RCW
70.95J.020 and
70.95.255. 98-05-101 (Order
97-30), § 173-308-270, filed 2/18/98, effective
3/21/98.