Why Focus on Reducing Rainwater Runoff Instead of Costly Sewer Upgrades
Green infrastructure solutions for deficient waste water systems throughout New Jersey are becoming as effective as they are cost saving. So much so, the State Department of Environmental Protection (NJDEP) recently announced new permits for the state’s 25 utility companies operating combined sewer systems (CSS’s). These new permits require affected towns and sewer treatment authorities to create and adopt plans to address the problems triggered by the sewer systems. The NJDEP is looking for local leaders to employ more green infrastructure as a key element of stormwater runoff.
Each CSS collects stormwater runoff, untreated sewage and industrial wastewater in the same pipe. Combined stormwater and sewage can overwhelm treatment plants when it rains, and the toxic slurry is able to flow into rivers through combined-sewer overflows (CSO’s). This problem can also spill over into neighboring communities. The focus on green infrastructure is to develop cost-effective measures to discharge stormwater before it reaches the sewer system using environmental enhancements.
Under these new permits, entities may propose a variety of approaches to mitigate CSO problems, as long as they are cost-effective and can meet required reductions in overflows of untreated sewage. The reintroduction of natural and sustainable features such as vegetation, porous asphalt and rain gardens are just some of these measures municipalities across the state are already implementing. Local governments can now work with utility authorities to put in place innovative, green solutions to keep waterways clean while adding or improving parks, gardens and streetscapes. All of these measures have already proven to help address flooding and reduce costs.
Many communities pay for green infrastructure projects by drawing from general funds, as many techniques are relatively inexpensive. Others set up new fees, taxes and other directed charges to help fund green infrastructure, similar to any other public infrastructure repair or improvement. Often, these fees are applied to new development and other land use alterations and may appear as plan review and permitting fees, or special assessment fees that discourage building in particular locations (like green fields) by exacting an additional charge for projects located in sensitive areas. Some communities are charging private properties a “fee in-lieu” of on-site water quality treatment, wherein developers no longer implement on-site water quality treatment practices, but instead pay into a fund that the municipality can use to finance green infrastructure projects in priority areas.
Encouraging infill and development over green field construction is ultimately the biggest flood mitigation technique. It also keeps utility maintenance costs down. A recent study completed in Western Australia found that the City of Perth saves $94.5 million for every 1,000 infill lots developed compared with the costs of developing new greenfield sites.