Changes

'''The fundamental components of an infiltration chamber system are:'''

'''The fundamental components of an infiltration chamber system are:'''

*Structurally reinforced chambers, vaults, crates, perforated pipes or other void-forming structures;

*[[Pretreatment]] devices to retain trash, debris, sediment and floatables and prevent clogging of inlets, underlying native soil and outlets;

*[[Reservoir_gravel|Coarse aggregate]] to embed the void-forming structures and temporarily store water;  

*Storage reservoir consisting of structurally reinforced chambers, vaults, crates, perforated pipes or other void-forming structures embedded in [[Reservoir_gravel|coarse aggregate]];  

*[[Pipes|Pipe]] to convey water into and out of the practice; and

*[[Pipes|Pipes]] and possibly flow control structures to convey water into and out of the practice; and

*[[Geotextiles]] to maintain separation between the storage reservoir and surrounding native soil.

*[[Geotextiles]] to maintain separation between the storage reservoir and surrounding native soil.

{| class="wikitable"

{| class="wikitable"

! rowspan="2"|System type  

! rowspan="2"|System type  

! Pipe

! Perforated pipes

! Vaults

! Vaults

! Arched chambers

! Arched chambers

|[[File:SWM Crates.jpg|frameless]]

|[[File:SWM Crates.jpg|frameless]]

|-

|-

| Materials || Plastic || Concrete || Plastic/concrete || Plastic

| Materials || Plastic or Metal || Concrete || Plastic || Plastic

|-

|-

| Footprint || Medium || Small || Large || Small

| Footprint || Medium || Small || Medium || Small

|-

|-

| Stackable || Not usually (can be without infiltration) || Yes || Not usually (can be without infiltration) || Yes

| Stackable || Yes || No || Yes || Yes

|-

|-

| Onsite assembly || No || No || Yes || Yes

| Effective Porosity (n') || 0.60 - 0.65 || 0.75 - 0.85 || 0.50 - 0.65 || 0.95

|-

|-

| Void ratio || 60-65% || 75-85% || 50-65% || 95%

| Maintenance Access || Moderate || Excellent || Moderate || Difficult

|-

|-

| Standard Strength || H-20  || H-25 || H-20 || H-20 - H-25

| Standard strength || H-20  || H-25 || H-20 || H-20 to H-25

|}

|}

==Planning Considerations==

==Planning Considerations==

Both modular systems require a bedding of angular clear stone to permit infiltration, and provide a foundation for the installation:  

All types of modular infiltration systems require a bedding of angular clear stone to permit infiltration, and provide a foundation for the installation:  

*Plastic modules usually have a parabolic shape to resist the load above. The spaces between the rows of modules are filled with clear stone to support the overlying infrastructure.

*Plastic chambers usually have a parabolic shape to support the load above. The spaces between rows of plastic pipes or chambers are filled with clear stone to support overlying structures.

*Concrete modules are often box shaped and can, in some circumstances, be employed without any additional cover. However, a minimum of 20 cm cover is recommended for most applications. Where this cover is planting soil this can support turf grass. Greater planting soil depths are required to support more deeply rooting plants like perennials and shrubs (45 to 60 cm) and trees (85 to 100 cm).

*Concrete vaults and plastic crates are often rectangular-shaped. Concrete vault systems can, in some circumstances, be employed without any additional cover. However, a minimum of 20 cm cover is recommended for most applications. Where this cover is planting soil this can support turf grass. Greater planting soil depths are required to support more deeply rooting plants like perennials and shrubs (45 to 60 cm) and trees (85 to 100 cm).

==Design==

==Design==