Code of Maine Rules
06 - DEPARTMENT OF ENVIRONMENTAL PROTECTION
096 - DEPARTMENT OF ENVIRONMENTAL PROTECTION - GENERAL
Chapter 419 - SOLID WASTE MANAGEMENT RULES: AGRONOMIC UTILIZATION OF RESIDUALS
Appendix 096-419-A - Loading Rate Calculations

Current through 2024-38, September 18, 2024

1.Nitrogen Loading Rate Calculations

A. The Percent of Organic Nitrogen Mineralized from Sewage Sludge must be assumed as in table 419.6, unless residual specific information obtained in accordance with 06-096 CMR ch. 405 is available. For other residuals, the generator must determine residual mineralization rates through sampling, in accordance with 06-096 CMR ch. 405:

Table 419.6

Percentages of Organic Nitrogen Mineralized after Sewage sludge of various types are land applied

B. When detailed information regarding organic sources of nitrogen from past utilization of residuals or manure and cropping practices is not available, soil organic matter must be assumed to provide 10 pounds of available nitrogen per acre per 1% organic matter over 5%. (i.e. if organic matter in soil is 6.5% the soil provides 10 lbs. x (6.5-5) = 10 lbs. x 1.5 = 15 lbs. per acre).

C. Unless otherwise approved by the Department, crop nitrogen needs must be determined based on the recommendations in the "Soil Testing Handbook for Professionals in Agriculture, Horticulture, Nutrient and Residuals Management, (3rd edition, 1997). Other crop needs will be determined by the Department on a case by case basis, based on recommendations from the Maine Cooperative Extension's Maine Soil Testing Service and Analytical Laboratory at the University of Maine in Orono, and other agricultural or silvicultural sources.

D. Loading rates of residuals based on Nitrogen need must be calculated as follows, based on representative residual analysis:1

Line

Parameter

Value

Unit

1.

Available Nitrate-N = %NO3-N2 x 2000 lbs/ton

lbs NO3-N / ton residual

2.

Available Ammonium-N= Recovery fraction3 x %NH4-N4 x 2000 lbs/ton

lbs NH4-N/ ton residual

3.

Available Inorganic N/ton residual = Available NH4 [line 2] + NO3-N [line 1]

lbs Inorganic N / ton residual

4.

Organic N = [Total N - Inorganic N [line 3]] x 2000 lbs/ton

lbs Organic N / ton residual

5.

Available Organic N = Organic N [Line 4] x mineralization rate5

lbs Available Organic N / ton residual

6.

Available N from the residual that was applied in previous years6

lbs Available Organic N / ton residual

7.

Total Plant Available N = Inorganic N [line 3] + Avail Org N [line 5]

lbs Available N / ton residual

8.

Total Available N required from residual = N needs of crop7 - Credits from Crop History8 - Mineralized N from previous years application [line 6]

lbs Available N/ acre-yr

9.

Residual Application (dry) Rate = N required from residual / Avail N from residual [line 8 / line 7]

dry tons residual / acre-yr

10.

Residual Application (wet) Rate = Dry Residuals Rate [line 9] / % Solids

wet tons residual / acre-yr

11.

If Applicable: Residual Application (wet) Rate per cut of hay = [line 10] / 2 cuttings

wet tons residual / acre-cutting

NOTE: References Cited and Other guidance on agronomic rate calculations:

Boub, Tom, George O. Estes, James R. Mitchell and David Seavey, June 1995, "Best Management Practices: Biosolids" (University of New Hampshire Cooperative Extension, UNH, Durham, NH).

EPA, December 1994, "Land Applications of Sewage Sludge: A Guide for Land Appliers on the Requirements of the Federal Standards for the Use or Disposal of Sewage Sludge", 40 CFR 503 as amended up to July 1, 2014 (EPA/831-B-93-002b, USEPA, OECA, Washington, DC).

EPA, October 1983, Process Design Manual: Land Application of Municipal Sludge (USEPA, Environmental Research Laboratory, Cincinnati OH, EPA-625/1-83-016).

Hoskins, Bruce R., 1997, "Soil Testing Handbook for Professionals in Agriculture, Horticulture, Nutrient and Residuals Management, 3rd edition (Formerly Soil Testing Handbook for Professional Agriculturists), (Maine Soil Testing Service, 5722 Deering Hall, University of Maine, Orono, ME).

Huddleston, J.H. and M.P. Ronayne, September 1995, Manual 8: Guide to Soil Suitability and Site Selection for Beneficial Use of Domestic Wastewater Biosolids (Cooperative Extension Service, Agricultural Communications, Oregon State University, Administrative Services A422, Corvallis, OR 97331-2119).

2.Pollutant Loading Calculations

A.Annual Pollutant Loading Rate Calculation. To determine the annual loading rate of heavy metals or other pollutants at a utilization site, use equation 419.1 as follows

(Equation 419.1)

APLR = LR * RPc * .001

where:

APLR - Annual Pollutant Loading Rate in kg-pollutant/ha

LR - Residual loading rate in mt-residual/ha (amount of residual applied in a year)

RPc - Pollutant concentration in the residual in mg-pollutant/kg-residual

.001 - Conversion factor = 1,000 kg/mt * 0.000001 kg/mg

B.Cumulative Pollutant Loading Rate Calculation. To determine the cumulative pollutant loading rate of heavy metals or other pollutants at a utilization site, sum the annual pollutant loading rates for the site, as shown in equation 419.2.

(Equation 419.2)

CPLR = APLR1 + APLR2 + ... APLRn

(Equation 419.4)

where:

CPLR - Cumulative Pollutant Loading Rate in kg-pollutant/ha at the site

APLR1 - Annual Pollutant Loading Rate during the first year in kg-pollutant/ha

APLR2 - Annual Pollutant Loading Rate during the second year in kg-pollutant/ha

APLRn - Annual Pollutant Loading Rate during the nth, or most recent, year in kg-pollutant/ha

C.Estimation of Soil Pollutant Concentration Increase Based on Residual Pollutant Concentration. To estimate the pollutant concentration in soil that will result from the cumulative loading of a pollutant in a residual at a site, use equation 419.3.

(equation 419.3)

SI = (RPc * LR * SL) / (2000)

Where:

SI - Cumulative soil concentration increase in mg-pollutant/kg-soil

RPc - Pollutant concentration in the residual in mg-pollutant/kg-residual

LR - Residual loading rate in mt-residual/ha/yr (amount of residual applied in a year)

SL - Site Life, or the number of times the residual will be applied at the site in 100 years, in years.

2000 - is the assumed dry mass of soil in mt/ha (dry weight) in a plow layer 15 cm thick (based on a bulk density of 1.33 g/cm3)

D.Common Conversions

(1) Dry tons / acre * 2.24 = Dry metric tons / hectare

(2) Wet tons * (% solids * 0.01) = Dry Tons

(3) Approximation based on weight of water: wet tons/acre * 239.7 gallons/ton = gallons/acre

(4) Approximation based on weight of water: 1 yd3 sludge = 27ft3/yd3 * 63.0 lb/ft3 = 1700 lbs

(5) Approx. based on weight of water: 1 yd3 sludge = 1700 lbs/yd3 ÷ 2000 lb/ton = 0.85 tons

(6) Approx. based on weight of soil: lb/acre ÷ 2 = ppm

(7) lb/acre * 1.121 = kg/ha

(8) 1 acre = 43,560 ft2

(9) 1 acre of soil six inches deep = approx. 2,000,000 lbs

(10) 1 lb = 0.453 kg

(11) 1 lb P = 2.29 lb P2O5 (phosphoric acid)

(12) 1 lb K = 1.2 lb K2O (potash)

(13) 1 ppm (in water) = 1 mg/l

(14) 1 ppm (in soil) = 1 mg/kg

(15) soil metal concentration in soil (ppm) = loading rate (lbs/acre) / 2

1 Modified from Boub, et al. 1995.

2 From Residual Analysis

3 When surface applied, approximately 50% of the Ammonium NH4-N Nitrogen will be lost to volatilization. Recovery fraction is the portion of Ammonium that does not volatilize.

4 From Residual Analysis

5 Mineralization rates are specified in appendix A, section 1.A above. A weighted average of these percentages may be used for combined sludges.

6 See Appendix A, section 1.A or Section 1.B above

7 See Hoskins, Bruce R., 1997, "Soil Testing Handbook for Professionals in Agriculture, Horticulture, Nutrient and Residuals Management, 3rd edition (Formerly Soil Testing Handbook for Professional Agriculturists), (Maine Soil Testing Service, 5722 Deering Hall, University of Maine, Orono, ME).

8 This includes the pounds of nitrogen per acre available to the crops from corn silage, animal manure, and / or cover crops.