Description. This work shall consist of incorporating compost within the root zone of the planned vegetation cover to improve soil quality and evapotranspiration.
Compost Application Procedure. Amended Soils
- Clear surface of obstructions and properly dispose. The soil surface shall be reasonably free of all objects, including stone and rubble, greater than 2 inches, and other material which will interfere with planting and subsequent site maintenance.
- Rototill to a depth of 6-8″ for turf cover and a minimum of 12″ for deep rooted vegetation. If the soil is too dense for a rototiller, the soil should first be broken up into large aggregates using a soil ripper.
- If obstructions are unearthed during tilling, clear obstructions and properly dispose of. The soil surface shall be reasonably free of all objects, including stone and rubble, greater than 2 inches, and other material which will interfere with planting and subsequent site maintenance.
- Distribute compost evenly to a minimum depth of 2 inches over the soil surface.
- Rerototill several times in perpendicular directions to incorporate compost and other soil amendments.
- Complete with fine grading and sodding.
- Water thoroughly. Allow soil to settle for one week.
Compost. Compost shall be mature, stable, weed free, and produced by aerobic decomposition of organic matter. Compost feedstock may include, but is not limited to: agricultural, food or industrial residuals; class A biosolids as defined in the EPA CFR Title 40, Part 503; yard trimmings, or source-separated municipal solid waste. The product must not contain any visible refuse or other physical contaminants, substances toxic to plants, or over 5% sand, silt, clay or rock material by dry weight. The product shall possess no objectionable odors. The product must meet all applicable USEPA CFR, Title 40, Part 503 Standards for Class A biosolids. The moisture level shall be such that no visible water or dust is produced when handling the material.
Testing. Prior to delivery of any compost to the site and as part of shop drawing review, the following documentation shall be provided by the contractor to the District Inspector:
- feedstock percentage in the final compost product
- a statement that the compost meets federal and state health and safety regulations
- a statement that the composting process has met time and temperature requirements
- a copy of the lab analysis, less than four months old, performed by a Seal of Testing Assurance Certified Laboratory verifying that the compost meets the physical requirements as described in Table 1.
Sod. Fertilizing, Sodding and Watering to be in accordance with MSD Standard Construction Specifications Part 8 Section F.
Table 1. Physical Requirements for Compost
|Soluble Salt Concentration||< 10dS/m||TMECC 4.10-A|
|Moisture||30-60% wet weight basis||SMEWW 2540B|
|Organic Matter||30-65% dry weight basis||TMECC 5.07-A|
|Total Nitrogen (N)||>1.00% dry weight basis||TMECC 04.02-D|
|Phosphate (P2O5)||>0.50% dry weight basis||TMECC 04.03-A|
|Potash (K2O)||>0.10% dry weight basis||TMECC 04.04-A|
|Particle Size||95% pass through 5/8″ screen or smaller||TMECC 2.02-B|
|Stability (Carbon Dioxide evolution rate)||>80% relative to positive control||TMECC 5.08-B|
|Maturity (Seed emergence and seedling vigor)||>80% relative to positive control||TMECC 5.05-A|
|Physical contaminants (man made inerts)||<1% dry weight basis||TMECC 3.08-A|
|Chemical contaminants||Meet or exceed US EPA Class A standard, 40 CFR § 503.13, Tables 1 and 3 levels:|
|Arsenic||< 41 ppm||TMECC 4.06-AS|
|Cadmium||< 39 ppm||TMECC 4.06-CD|
|Copper||< 1,500 ppm||TMECC 4.05-CU|
|Lead||< 300 ppm||TMECC 4.06-PB|
|Mercury||< 17 ppm||TMECC 4.06-HG|
|Molybdenum||< 75 ppm||TMECC 4.05-MO|
|Nickel||< 420 ppm||TMECC 4.06-NI|
|Selenium||< 100 ppm||TMECC 4.06-SE|
|Zinc||< 2,800 ppm||TMECC 4.06-ZN|
|Biological contaminants (pathogens)||Meet or exceed US EPA Class A standard, 40 CFR § 503.32(a) levels:|
|Fecal coliform||< 1,000 MPN per gram, dry weight basis||TMECC 7.01|
Recommended compost testing methodologies and sampling procedures are provided in Test methods for the Examination of Composting and Compost (TMECC), and Standard Methods for the Examination of Water and Wastewater.