Section 327IAC6.1-4-10. Loading rate limits

   (a) Maximum crop and annual loading rates are determined for a biosolid or industrial waste products to be applied on the basis of the following parameters:

(1) Crop application rates, based on plant available nitrogen (PAN) loadings using the appropriate formulas in subsection (b), shall not exceed either of the following:

(A) PAN loading rates for crop production in Table 5 as follows:

Table 5 Plant Available Nitrogen Loading for Crop Production
Crop	Pounds of PAN Per Acre1
Corn	200
Soybeans	100
Hay, pasture	100
Cereal grain	100
Set aside/idle	50
1An equivalent method of meeting the nutrient management requirement may be submitted to the commissioner for approval for alternative nutrient loading rates that provide equivalent or greater protection to the environment and public health.

(B) The nitrogen removal rate for the proposed crop to be grown on the land application site adjusted to account for application of fertilizers, manure, and the presence of residual available nitrogen in the soil from previous applications of a biosolid, industrial waste product, or pollutant-bearing water.

(2) Annual loading rates of a biosolid or industrial waste product must not result in any of the annual pollutant loading rates in Table 4 in section 9(d) of this rule being exceeded. The following formula for annual loading rate calculation applies to this article and must be used to calculate the amount of biosolid or industrial waste product to be applied per acre per three hundred sixty-five (365) day period:

Where:	ALR	=	Annual loading rate in dry tons per acre per three hundred sixty-five (365) day period (dry, short ton of biosolid or industrial waste product/acre/year).
	APLR	=	Annual pollutant loading rate in pounds per acre per three hundred sixty-five (365) day period (pounds/acre/year).
	C	=	Pollutant concentration in milligrams per kilogram of total solids (mg of pollutant/kg of biosolid or industrial waste product dry weight).

(3) Phosphorus loading requirements may be included as a permit condition if the commissioner determines it is necessary for protection of public health or the environment.

  (b) The following formulas for PAN loading calculations apply to this article and must be used to calculate the amount of PAN in the biosolid or industrial waste product and the residual available nitrogen at the application site; all calculations are based on a percent dry weight basis:

(1) %Total N = %Total Kjeldahl N + %Nitrate N

(2) %Organic N = %Total N - (% Ammonia N + %Nitrate N)

(3) Pounds Organic N per dry ton of industrial waste product or biosolid, except anaerobically digested biosolid, available during year of application = %Organic N × 6

(4) Pounds Organic N per dry ton of anaerobically digested biosolid available during year of application = %Organic N × 4

(5) Pounds of Ammonia N per dry ton = % Ammonia N × 20

(6) Pounds of Nitrate N per dry ton = %Nitrate N × 20

(7) Pounds PAN per dry ton = Pounds of Organic N per dry ton + Pounds of Ammonia N per dry ton + Pounds of Nitrate N per dry ton

(8) Residual nitrogen from past biosolid or industrial waste product applications:

(A) Pounds of residual N from industrial waste product or biosolid, except anaerobically digested biosolid, available one (1) year after application = %Organic N × 3 × dry tons applied per acre

(B) Pounds of residual N from anaerobically digested biosolid available one (1) year after application = %Organic N × 2 × dry tons applied per acre

(C) Pounds of residual N from industrial waste product or biosolid, except anaerobically digested biosolid, available two (2) years after application = %Organic N × 1.6 × dry tons applied per acre

(D) Pounds of residual N from anaerobically digested biosolid available two (2) years after application = %Organic N × dry tons applied per acre

(E) Pounds of residual N from industrial waste product or biosolid, except anaerobically digested biosolid, available three (3) years after application = %Organic N × 0.8 × dry tons applied per acre

(F) Pounds of residual N from anaerobically digested biosolid available three (3) years after application = %Organic N × 0.5 × dry tons applied per acre

Where:

N

=

Nitrogen.

(Water Pollution Control Division; 327 IAC 6.1-4-10; filed May 15, 1998, 10:20 a.m.: 21 IR 3794; readopted filed Jan 10, 2001, 3:23 p.m.: 24 IR 1518; filed Jul 7, 2003, 4:25 p.m.: 26 IR 3612; readopted filed Nov 21, 2007, 1:16 p.m.: 20071219-IR-327070553BFA; readopted filed Jul 29, 2013, 9:21 a.m.: 20130828-IR-327130176BFA)