Section 113.09. Application rates.

 

(1)   General. Septage shall be applied only to agricultural lands and may not be applied at rates which will supply available nitrogen at amounts greater than the agronomic need for the crop grown as calculated by sub. (4) . Yearly loading rates listed in Table 4 may be used if the crop grown on a low use field requires 100 lbs-N/ac or more. If the crop requires less than 100 lbs-N/ac, the loadings shall be reduced in accordance with the equation in sub. (4) .

(2)   High use fields. The volume of septage applied annually on a high use field may not exceed the amount calculated in sub. (4) which is necessary to supply the nitrogen needs of the crop to be grown, as determined by the analysis of soil samples. The nitrogen crop needs shall be based on the university of Wisconsin extension bulletin A-2100, dated April 1991 ("soil information sheet"), or soil sampling guidance approved by the department, except as allowed in sub. (3) .

(3)   Specific crops on high use fields. Septage may be applied to most leguminous crops at a volume sufficient to supply 200 lbs/ac of available nitrogen. If septage is applied to soybeans, the loading shall be limited to 140 lbs/ac of available nitrogen.

(4)   Annual agronomic rate. For the purpose of implementing this section, septage may not be applied at a rate that exceeds the following: - See PDF for table

(5)   Maximum loading. The hydraulic loading rate of application shall be limited by soil characteristics but under no conditions may it exceed 13,000 gallons per acre per week for holding tank or septic tank contents or a combination of the 2. Ponding of septage shall be prohibited.

(6)   Grease interceptors. Waste from grease interceptors shall be disposed of at a department licensed sanitary landfill, land applied or through some other department approved method.

(a) Contents of grease interceptors that are land applied to agricultural lands shall be incorporated, injected or mixed with septage at a level not to exceed 25% grease interceptor wastewater and applied in accordance with sub. (5) .

(b) The hydraulic loading rate for land application shall be limited by soil characteristics but under no conditions may exceed 4,300 gallons per acre per application for grease interceptor contents. Ponding of the grease interceptor wastewater is prohibited. - See PDF for table

1 The maximum annual hydraulic loading that will be permitted for any high use field will be based on the annual agronomic application rate computed by using the formula in sub. (4).

2 If the crop grown on a low use field requires less than 100 lbs N/ac, the max. annual hydraulic loading that is permitted is based on the annual agronomic application rate in sub. (4).

History: Cr. Register, September, 1996, No. 489 , eff. 1-1-97.