Feedback post on Bioretention: Filter media

Rename first table title "Filter Media Blend Options" and the second "Filter Media Specifications and Test Methods" Fix typo in first table under Blend B, Proportions - delete "sand" from the third line. Should recommend that topsoil used in blending filter media should be passed through a 2" screen to remove large debris and stones. Should recommend that compost be passed through a maximum 1 inch screen or specify 1" screened compost from the supplier. In the second table regarding preferred test method for Phosphorus, the choice of test method depends on whether or not the soil is calcareous or not. My understanding from the soil testing industry is that in agricultural Ontario, they assume calcareous topsoil and use Olsen as the default unless Calcium content indicates it is not calcareous. See the STEP LID I&M Guide section 8.2.8 Phosphorus for more and a citation to document that provides test methods for both test methods and more on when to use what. In the second table, separate acceptable ranges for specifications should be provided for the two design objective/blend options. Specifications associated with texture should include acceptable ranges for sand sized particles and anything greater than sand content (pebbles, chunks of organic matter, plastic, etc.) along with what soil texture class the range encompasses according to the Canadian Soil Classification System. Basically we want filter media to be a Loamy Sand if volume reduction is the priority or Sandy Loam (some maybe not all?) if water quality is the priority. Regarding the criterion in table 2, CEC should be "> 10 mEq/100g", Hydraulic conductivity could be tweaked to "> 25 mm/h; < 305 mm/h". This is roughly 1 inch/hour to 12 inches/hour. I think additional guidance should be provided to help users and soil blenders to determine if available topsoil and compost material is suitable for use in blending filter media. This could be some acceptable ranges for particle size distribution/soil texture, salt content, Sodium Adsorption Ratio (SAR), Carbon to Nitrogen Ratio (for compost) and maximum particle (i.e., screen) size. A source of this info is in the Compost Amended Planting Soil Specification template at the following URL: https://sustainabletechnologies.ca/home/urban-runoff-green-infrastructure/healthy-soils/construction-specifications-for-implementing-compost-amended-planting-soil-in-ontario/ In the table "Soil Additives" add Manganese oxide-coated sand (UC Berkeley researcher, J. Charbonnet, Copper coated zeolite (Australian research, to boost bacteria inactivation), "pitchers' mound clay" - there may be a standard in the US for this.