AT-SOURCE GRATED INLET OR IN-LINE PRIMARY TREATMENT SOLUTION

This compact at-source or in-line system is designed specifically to provide primary treatment of stormwater flows in one fully self-contained underground device. It consists of a primary treatment filtration basket for retention of sedimentation larger than 200 micron, a series of baffles and detention bay for retention free floating hydrocarbons and gravitational separation of finer sedimentation.
It is designed to treat 100% of incoming flows up to its designed treatable flow rate, capturing and retaining pollutants conveyed from impervious areas in a rain event, either at point of source or in-line.
Compact and flexible and installed underground the Ecosol Storm Pit (Class 1) system is designed for use in hardstand and trafficable car parks in typical, medium-density housing estates and small commercial developments up 500m2. It suits pipe sizes from 100mm to 225mm in diameter.
STORM PIT CLASS 1 KEY FEATURES AND BENEFITS
- Compact, cost efficient stormwater treatment solution for high density developments
- Supplied as a complete system housed in its own pre-cast pit ready for installation
- Easily maintained by vacuum truck
- Captures and retains gross litter, sedimentation and hydrocarbons
- Durable robust product engineered for the environment in which it operates
- Treats 100% if incoming flows up to its designed TFR.
At Urban Asset Solutions we can site measure, fabricate, install and maintain your Storm Pit making the whole process seamless.
Ecosol STORM PIT - CLASS 1 (PRIMARY TREATMENT SYSTEM) | ||||
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Product Code | Maximum outlet pipe diameters | Approximate external unit dimensions (L x W x D from surface level to pit base) | Approximate unit weight | Loading classification |
(mm) | (mm) | (t) | ||
Storm Pit 7L Class 1 | 100 | 1200 x 900 x 1050 | 2.0 | D |
Storm Pit 13L Class 1 | 150 | 1200 x 900 x 1050 | 2.0 | D |
Storm Pit 15L Class 1 | 225 | 1200 x 900 x 1050 | 2.0 | D |
Ecosol Storm Pit (Class 1) Typical System Configurations - 2018 |
Please Note: For optimal operation the system requires a minimum drop from the grated inlet or inlet pipe invert to the outlet pipe invert level of approximately 430mm.
Ecosol STORM PIT - CLASS 1 HYDRAULIC SPECIFICATION | |||
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Ecosol Product Code | Maximum Inlet and Outlet Pipe Diameters | Maximum Treatable Flow Rates (L/S) | Maximum By-Pass Flow Rates (L/S) |
(mm) | (mm) | (t) | |
Storm Pit 7L Class 1 | 100 | 7 | 12 |
Storm Pit 13L Class 1 | 150 | 12 | 22 |
Storm Pit 15L Class 1 | 225 | 15 | 63 |
Ecosol Storm Pit (Class 1) Hydraulic Specification - 2018 |
Treatable Flow Rate (TFR) is defined as the maximum flow rate through the Ecosol Storm Pit (Class 1) before flows surcharge and commence by-passing the system untreated. The TFR is constrained by the friction capacity and size of the outlet conduit and the percentage of unit fill. For the purpose of assisting designers we have adopted conservative values and recommend designing the system with an outlet at 1% gradient to achieve optimal capture efficiencies and maximum treatable flow rates. Further each system has been designed specifically to cater for peak flow by-pass conditions in the event that the system is full of contaminants and a significant storm event is occurring. This fail safe by-pass eliminates the risk of potential localised flooding.
This system is designed specifically as a primary treatment system to treat stormwater runoff for typical developed urban catchments up to 250m2 based on a 100% impervious catchment area. The system provides essential pre-screening of stormwater flows. The Ecosol Storm Pit (Class 1) is the ideal treatment solution for applications where space is limited.
Ecosol STORM PIT CLASS 1 - POLLUTANT CAPTURE EFFICIENCY | ||
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Pollutant | Capture Efficiency | Details |
Gross Pollutants (GP) | 100% | Particulate > 2000 micron |
Total Suspended Solids (TSS) | 52% | Particulate 20 - 2000 micron |
Total Phosphorus (TP) | 40% | Particulate and dissolved mean average efficiency |
Total Nitrogen (TN) | 16% | Particulate and dissolved mean average efficiency |
Heavy Metals | 40% | Particulate and dissolved mean average efficiency less standard deviation |
Total Petroleum/ Hydrocarbon (TPH) | 90% | In dry weather emergency oil spill situations |
50% | In an event | |
Storm Pit (Class 1) Pollutant Capture Efficiency - 2018 |
The Ecosol Storm Pit (Class 1) provides engineers with a compact stormwater treatment measure that when implemented with other measures such as rain gardens or swales will achieve the necessary Water Quality Objectives.
Figures quoted are mean pollutant removal efficiencies based on available product testing data. It is important to note that these values are indicative only, given that the product is designed as a primary treatment system and as such the removal of chemical constituents is largely dependent of the composition of the particles retained within the system and the bonding of constituents to these retained particles.

The Ecosol Storm Pit (Class 1) system is a compact at-source or in-line system that is designed specifically to provide primary treatment of stormwater flows in one compact device.
Typical applications include:
- small commercial developments
- urban roads kerbside inlets
- and high density residential developments.
As with all filtration systems, the Ecosol Storm Pit (Class 1) should be cleaned regularly. During the first two years of operation it is important to regularly monitor and maintain the system to better determine long-term maintenance regimes. All elements within the Ecosol Storm Pit (Class 1) have been designed for easy safe and cost efficient cleaning by vacuum method. Initially Urban Asset Solutions recommends the primary treatment litter basket is cleaned 2 – 3 times annually and the sump at least once annually.
One of the key advantages of the Ecosol Storm Pit (Class 1) is that both the primary litter basket and wet sediment sump can be easily cleaned by vacuum method using a vacuum truck from surface level. This eliminates any risks associated with manually handling captured pollutants or confined space entry.
Ecosol STORM PIT - CLASS 1 MAINTENANCE FREQUENCIES | |||||
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Ecosol Storm Pit (Class 1) Product Code | Pollution Holding Capacities | Optimal Catchment Area (Ha) | Recommended Cleaning Frequency |
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Gross Pollutants | Sediment | Sediment | |||
m3 | m3 | Litres | Ha | Per Annum | |
Ecosol Storm Pit (Class 1) 7L | 0.09 | 0.072 | 67 | 0.25 | 1 |
Ecosol Storm Pit (Class 1) 13L | |||||
Ecosol Storm Pit (Class 1) 15L | |||||
Ecosol Storm Pit (Class 1) Maintenance Frequencies - 2018 |
Indicative Catchment Size and Recommended Cleaning Frequencies for the Ecosol Storm Pit (Class 1)
Cleaning frequencies are based on typical pollution loads of 0.280m3/ha/year for gross pollutants and 0.380m3/ha/year for Sediment generated on a typical fully developed urban catchment. For larger catchments increase cleaning frequencies will be required
Urban Asset Solutions can provide MUSIC modelling, system design specific for your project. We also manufacture in-house all components and commission and maintain your Ecosol Storm Pit (Class 1), thereby providing you with a hassle free full turnkey service.