SECTION 252:616-11-2. Rates and frequencies

(a)   Loading restrictions. The loading requirements shall be subject to the following factors and criteria.

(1)   Hydraulic loading rates. Determine hydraulic loading rates by performing a water balance that includes precipitation rates, evapotranspiration data and properties of the soil and vegetation involved. Hydraulic loading shall not result in ponding or surface water runoff.

(2)   Concentration or mass loading rates. Concentration or mass loading rates at a minimum shall not exceed the assimilative capacity of the soils as determined on a site-specific basis.

(3)   Nutrient loading. The amount of nitrogen to be applied to the soil (lbs/acre/year) shall be determined using the amount of plant available nitrogen (PAN) in the applied wastewater or sludge and the nitrogen uptake rate of the vegetation. Maintain Nitrogen and Phosphorus loading rates to minimize infiltration or transfer of nutrients in concentrations which may impact groundwater or surface water.

(4)   Organic Loading. Loading rates shall be below levels where clogging of the soil could occur. Rest periods are required between successive applications.

(5)   Application rate and frequency of application. The rates and maximum frequency of land application are determined by the DEQ based on site-specific data (e.g., runoff and erosion controls, average precipitation rates and temperatures, assimilative capacity and infiltration rates of the soil), loading rates, sludge or wastewater characteristics and the proposed method(s) of application.

[Source: Added at 17 Ok Reg 1925, eff 6-12-00]