maintenance equipment. Group agreed. PLANTING PLAN 1 Annette – How about: A minimum of one tree, three shrubs and three herbaceous species shall be incorporated in the bioretention planting plan unless it is a grassed cell. A recommended planting density is 400 stems per acre. Brian L – This should be a recommendation. Robert – Not worded well – trees, shrubs vs species, any combination of these? Brian L – For water quality purposes, does it really matter? Annette – What if we wanted it to be more outcome oriented? Bill H – Plants are important. Roots are particularly important. Peter – Should it be plants of certain root depths? Not the top of plants that matter – should be root parts. Bill H – Mm hmm. Let’s come back to the Team on this later. Todd – Keep in mind maintenance requirements. It’s hard to image a system working in perpetuity if you have to take a big tree out to do maintenance. Annette – Trees love water and will go for that underdrain, clog it up. Bill and I will work on this. PLANTING PLAN 2 Annette: How about: Plant size shall be no less than 2.5” dbh for trees, 3 gallons for shrubs, and 1 quart for herbaceous plants. Annette – Bill and I will tackle 18-22 and bring back to Team. MULCH 1 Group agreed to strike this. 2 Brian L – Will be a headache if mulch washes away. Robert – I think we should require this. Rob W – Do you always buy your own mulch, not make it yourself? Why does it have to be commercially available? Brian L – Let’s lose “commercially available.” Robert – Do we want to specify that this does not apply to grass cells? Annette – How about: For tree/shrub bioretention cells, double or triple shredded hardwood mulch shall be used for the portion of the cell that will be inundated. (Explain in manual – because it is less likely to be washed away.) Group agreed. MULCH 3 For tree/shrub bioretention cells, mulch shall be uniformly placed 2-4 inches deep. (In chapter, mulch should be renewed as needed to maintain a 2-4 inch depth until the plants create their own mulch layer.) Group agreed
MULCH 4 Bill H – Once established, mulch may not be needed. Group agreed to move this item to manual (see Mulch 3). INTERNAL WATER STORAGE – Move to manual, already addressed above. NUTRIENT DC – Incorporated into credit table. RECOMMENDATIONS 1 and 2 Rob W – Recommendations 1 and 2 need to be studied by Annette and Bill RECOMMENDATION 3 Washed Number 57 stone should be installed around the underdrain. Group agreed. RECOMMENDATION 4 Group agreed to keep as is. RECOMMENDATION 5 Todd – Are any unique maintenance issues if you perch it like this? Bill H – Making sure that berm is maintained. Mike G – You’re going to impound 4 or 5 feet of water -- Annette – With water plus media, it could be pretty deep. Bill H – This was for bioretention cells up against a building. Robert – We have one at a fire station where there wasn’t room for a slope, so they built a wall on the side of the cell. Annette – It’s just another option. Action Items Annette –Annette –Send Team additional homework in 2 weeks. Annette and Bill – Study Recommendations 1 and 2 and work on Items 18-22 (see above) Team – Review chapters and additional homework as assigned. Next Meeting – November 17, 2014 – 9:30 to 3:00. Disconnected Impervious and Sand Filters