Romtec Utilities designs, supplies, and engineers pumping systems for all types of applications, including stormwater management. Designing stormwater pump stations today often requires that additional systems are included to improve the efficiency and sustainability of the stormwater infrastructure. One of these are stormwater treatment systems, which provide a reliable way to treat stormwater locally and reducing the strain on water treatment plants. These modular water treatment systems are valuable tools for stormwater infrastructure and are even a requirement for new developments in some areas.
Before diving into how stormwater treatment systems work it is important to understand why they are necessary in stormwater infrastructure today. In an undeveloped area, rainfall is deposited on the ground and is absorbed into the ground or evaporates into the air. Rainwater is filtered naturally as it permeates down and eventually rejoins the water table underground. Urban areas have many impervious surfaces that disrupt the water cycle like sidewalks, roads, and rooftops. Modular stormwater treatment systems emulate the natural water filtration process to treat collected stormwater locally and often do not require additional treatment. Some states, like California, even require modular water treatment systems on new developments to manage their water resources more responsibly.
All stormwater treatment (or modular water treatment) systems emulate the natural filtration process. Rather than soil filtering pollutants from stormwater, the biofilter in a modular water treatment system can use an engineered media or a natural media, like wood chips or bark mulch. Pollutants are transferred from collected stormwater to the chosen media when flowing through the system. The filtering media bed will eventually need to be replaced, but when this is necessary depends heavily on which media is chosen. This filtration process is the core functionality of all stormwater treatment systems, but the style and appearance of the system can vary greatly.
These modular stormwater treatment systems are available in many different styles and configurations to meet different flow rates and volume requirements. Sometimes these systems are installed openly and can even resemble flower beds on sidewalks. Others have been installed completely below-grade with access to the filtration media through a top hatch. Most below-grade systems are installed in areas where an open system is not possible. When an open bed style is appropriate modular water treatment systems are very customizable and can include a wide variety of plant life. Although many plants are available, the specific plants chosen will typically be suited for the climate of the region and the amount of rainfall the system will see. Plants should be well suited to “wetland” climates as they will have constantly saturated roots.
Stormwater treatment systems are valuable tools in modern water infrastructure. The natural water cycle is interrupted by impervious surfaces and these systems serve to emulate the natural filtration process. Modular water treatment systems come in many sizes and styles to meet the flow and volume requirements of each stormwater application. There are many different plants that can be planted in these systems, but the most successful systems take the climate of the area and the amount of rainfall experienced into consideration.
The Laguna Canyon Group project was a stormwater pump station with on-site water treatment that Romtec Utilities designed and supplied for a new retail outlet in San Clemente, California. This pump station is used to distribute low flows of stormwater collected from a different system and discharge it through a planter for on-site water treatment.
The low flow requirements of the biofiltration system required some water to be diverted back into the wet well using bypass piping to cool the pumps while in operation. This stormwater treatment system is an example of diverting stormwater into natural ground filtration instead of sending it through the impervious surface system that requires further treatment. This natural way of filtering stormwater improves the overall water quality in the water table.
Ebara 1/3 hp pumps were installed in a duplex configuration to meet the applications flow requirements with simple electrical controls with a reliable alternator relay suitable for this duplex pumping configuration. The controls were installed in a secure NEMA 4X fiberglass enclosure complete with an anti-condensation heater for year-round protection.
Another modular water treatment system Romtec Utilities designed and supplied was for the Bay 101 casino in San Jose, California. Each pump station will help serve new hotels as this casino facility expands. This project required six stormwater pump stations to handle the low flow requirements of stormwater while maintaining consistent head conditions.
To successfully do this, Romtec Utilities engineered four of the pump stations with 1/3 hp Goulds pumps in a simplex configuration. Another pump station was designed with a 1/2 hp pump, and the final pump station included a 1.5 hp submersible pump. These pumps, combined with 1.5” discharge piping, met the system’s design criteria without the need for any additional equipment.
Finally, Romtec Utilities designed and supplied a stormwater treatment system for the Doheny Village neighborhood in Dana Point, California. Recent city improvements required a new stormwater pump station for residential revitalization. To meet the required flows, the new pump station utilized a 1/3 hp Goulds submersible pump in a simplex configuration. This pump station is capable of pumping 50 GPM, and it pumps into a split force main that discharges into two modular water treatment systems for basic stormwater treatment.
NOLTA float sensors are used for liquid-level sensing and the control valves were engineered inside the wet well. This unique design created a low-cost stormwater configuration capable of utilizing modern modular water treatment system for stormwater treatment.
These stormwater treatment systems are a valuable asset to any local development or community that is putting in a residential neighborhood or commercial development. Not only can they handle stormwater events but they help with the filtration of water using the ground, various plants, and media to remove pollutants that otherwise would have to be treated at a local stormwater plant.
Call Romtec Utilities today for more information about stormwater treatment systems and stormwater pump stations!