WAC 173-308-270   Septage applied to the land.  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).

				Equation (3)
	AAR		=	N
				0.0026
Where:
	AAR = Annual application rate in gallons per acre per 365-day period.
	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).

     (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).

				Equation (4)
Drive length (in feet) = gallons in spreader ÷ spread width (in feet) x 43,560 ÷ AAR
Where:
	AAR = Annual application rate in gallons per acre per 365-day period.

     (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.]