Above ground and below grade storage and settling - installation and maintenance recommendations Above ground and below grade storage and settling - installation and maintenance recommendations

Above ground and below grade storage and settling - installation and maintenance recommendations
Link to this table

Device	Installation notes	Frequency of inspections	Maintenance checklist (link)	Permitted on private land/ Maintenance agreement recommended	Practices for minimizing sediment and trash buildup	Practices for minimizing erosion	Cost considerations (equipment needed and man hours)
Pretreatment row on underground storage/filtration	no data	At least every 6 months for first year of operation, then varies by location			Periodically remove sediment by back-flushing water and vacuuming manhole sump [1]		Vacuum truck
StormTech Isolator Row	Installation instructions available here.	At least every 6 months for first year of operation, then varies by location [2]	Step by step maintenance procedures		Clean-out when average depth of sediment exceeds 3 inches [3]		Vacuum/JetVac combination vehicle [4]
Prinsco HydroStor Sediment Row		More frequent during first year of operation, then varies by location			Clean-out when average depth of sediment ranges from 1-3 inches		Vacuum/JetVac combination vehicle
Settling chamber/vault					Remove sediment once depth reaches 6 inches or more [5]
Oil/water/grit separators		After every major storm but at least once per month [6]			Clean out at least twice per year [7]
Hydro Dry Screen		Every 3-6 months during first year, then site specific [8]	Maintenance and inspection checklist [9]		Remove sediment once depth exceeds maximum clean-out depth [10]		Vacuum truck
Suntree Nutrient Separating Baffle Box (NSBB)		After each runoff event initially, then at least quarterly. Local and State regulation may require every 90 days [11]	Inspection and maintenance checklist; [12]		Vacuum out sediment chambers when sediment accumulation exceeds 50% storage volume [13]		Vacuum truck
Manhole Baffle Box		Frequently for first two years following installation, then site specific [14]			Fully cleaned at least once per year [15]		Vacuum truck; One half day; Average cost $450 [16]
Environment 21 StormPro		At least quarterly until a more accurate schedule can be determined [17]	Maintenance data sheet		Sediment should be removed when sediment depth in first chamber is 50% of design sediment storage depth or at least once per year [18]		Truck-mounted sewer and catch basin cleaner with vacuum pump [19]
BaySeparator by BaySaver		At least every 6 months initially, then site specific [20]	Maintenance instructions		Cleaning recommended every 12-36 months or when 2 feet of sediment have accumulated [21]		Vacuum truck [22]
Sump Manhole with SAFL Baffle	45 minute installation [23]	Three times per year for first two years			Sediment removed before it reaches the bottom of the SAFL baffle		Vacuum truck [24]
Prinsco Preserver Dissipator	15 minute installation.	Spring and fall inspections recommended. More frequent inspections are recommended following installation until a routine maintenance frequency is be determined.	[25]	Yes	Sediment removed when average depth reaches 1x pipe dia. below the outlet.	na	Vacuum truck
Deep sump catch basin		Four times per year and at the end of foliage and snow- removal seasons [26]			Four times per year or when deposit depth is greater than ½ depth from bottom of invert to lowest pipe [27]	Hood required	Vacuum truck or clamshell bucket [28]
Forebay/pre-settling basin	Hard floor (concrete or grouted stone) allows definition of bottom and ease of maintenance. Provide appropriate stabilized maintenance access for heavier equipment at no more than 2% cross slope and no more than 10% longitudinal slope	Monthly [29]			Four times per year or when sediment depth is >3 ft. A hard bottom such as concrete facilitates removal, during design ensure forebay is vehicle accessible [30]; [31]	Forebay should be designed to withstand 2-yr and 10-yr velocities without scouring [32]	Vacuum truck skid-loader, or backhoe