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Figuring Compost, Stockpiling and/or Imported Topsoil Needs Step 1. Review site conditions, landscape and grading plans. • Examine site plans and soils. Use a shovel to dig in several areas that have been or will be graded to deter- mine if the newly exposed grades can be easily amended, or if compaction will require plowing/tilling of the subsoil or topsoil import. Determine if there are areas where soil could be stockpiled on -site. • Identify areas where soil can be: left undisturbed (Optionl), amended in place with compost (Option 2), re- moved and replaced with imported purchased topsoil (Option 4), or stockpiled and later reapplied (Option 3). Step 2. Select soil treatment option and suitable pH for each planting area. Amending with compost is often the most economical way to bring poor soils up to the required soil organic mat- ter content. On sites with the original, undisturbed, native soil, and where space permits, stockpiling and reapply- ing topsoil may be less costly. Importing topsoil usually costs more than amending existing soil, though it may be easier where subsoil conditions make cultivation difficult. • To determine a custom compost amendment rate for Options 2 and/or 3, use an accredited soil -testing labora- tory (website provided) to sample and test the site soil to determine the soil bulk density (lbs/cubic yard dry weight) and soil organic matter percentage. These values will be used to calculate the custom compost amendment rate in inches (see BMP T 5.13(3)). • Identify the areas where the selected Soil Treatment Option(s) will be applied. Outline those areas on the site plan with a dark, thick -line pen. • Assign each area an identifying letter (A, B, C... ) on the site drawing. • Determine desired pH for each lettered area, based on suitability for proposed plants. • Include required information on the Soil Management Plan Summary Form. Step 3. Calculate compost and/or topsoil volumes for each area. • Calculate the square footage of each lettered area on the Soil Management Site plan. • If using the pre -approved amendment rate, complete the attached Compost and Topsoil Calculation Work - sheet to calculate the quantities of compost and/or topsoil needed. Step 4. Identify compost and/or topsoils to be applied and retain records. • Contact a compost or topsoil facility permitted by Washington state and select products that meet the require- ments. • If preparing to use a custom compost amendment rate for Options 2 and/or 3: ■ Determine the target percentage of soil. organic matter you wish to achieve. Note: 8% is better for grassy areas and lawns and 10-13% is better for planting beds. ■ Request copies of compost test result reports that include the compost (lbs/cubic yard dry weight) and the percentage compost organic matter. These values will be used to calculate the custom amend- ment rate in inches. • Complete the Soil Management Plan Summary form in this bulletin, with required attachments. These will become part of your stormwater site plan documenting how you intend to comply with Minimum Requirement 5, On Site Stormwater Management. Retain original delivery tickets for compost and/ or topsoil products for verification purposes.