The same day last week the City Council helped us all breathe easier with a new law on chemicals in carpets, the Department of Environmental Protection released its new stormwater rule that encourages natural rainwater detention and retention, along with accompanying design guidelines. “Natural” here is not being used like the labels on cleaning products – here we are talking about honest to goodness mother nature. Rather than send rainwater to concrete tanks, sewers, and treatment plants, the new DEP rule encourages onsite reuse and natural infiltration.

It’s hard to overstate how much of a “180” this rule and the Green Infrastructure Plan represents for DEP, at least in terms of the principles involved. Until very recently, the only stormwater approach that mattered to DEP’s water engineers were those that could be measured in tanks and pipes. While we all know rainwater can be absorbed in the ground, directed into a rain barrel, and retained by a green roof, it wasn’t that easy to measure this capture. So it didn’t count at all for DEP. It does now.

The new rule is not a panacea for those who favor green infrastructure but is still a big step forward. The rule drastically reduces the allowable runoff from new construction and major reconstruction (a 90% reduction from previous limits). DEP will consider a range of approaches to reduce runoff including vegetative cover, green roofs, and permeable pavement. It will also consider open-bottomed detention systems that allow infiltration. Owners are required to provide maintenance for these systems so they work as intended. And finally, new developments next to a waterway must send rainwater into the waterway (rather than the sewer system).

Taken together, this rule implements 4 Task Force recommendations:

• SW 2: Reduce Stormwater Runoff From New Developments
• SW 4: Send Rainwater to Waterways
• SW 5: Encourage Innovative Stormwater Practices
• SW 6: Maintain Site-Based Stormwater Detention Systems

Another good day for green codes and a great way to kick off the New Year!

Coming on the heels of five NYC Green Codes Task Force laws enacted two weeks ago, this afternoon the City Council passed another package of four laws that will improve water efficiency and increase the availability of drinking water. To date, 16 Task Force recommendations have now been implemented.

After all the crazy storms of late, it can be hard for New Yorkers to remember the importance of water conservation. Although recent years have brought plenty of rainfall, New York City has faced seven droughts in the last 45 years. In addition, in approximately 2017 we will face a supply crunch when the city shuts down the Delaware Aqueduct to fix leaks. At that time, we will either need to reduce demand by 20% or find other sources (not now apparent) to ensure sufficient water supply. The laws passed today will reduce demand and ease the impact of future droughts and the anticipated 2017 shutdown.

Introduction 271 (Task Force proposal Water Efficiency 1) implements the primary water efficiency recommendation of the NYC Green Codes Task Force, increasing efficiency standards and requiring EPA’s WaterSense labels for plumbing fixtures starting July 1, 2012. The law will have a major impact over time. It will not require people to install the more efficient fixtures until they choose to make improvements to their bathrooms or kitchens, but we still estimate that 10 years after implementation, this law will save 61 billion gallons of water per year. After 20 years, consumption will be reduced by 80 billion gallons per year.

Introductions 268 and 263 (Task Force proposals Water Efficiency 3 and Water Efficiency 6, respectively) will reduce two types of large-scale water waste. Intro 268 will reduce leaks and waste from major equipment. Beginning in July 2011, new rooftop water tanks will need to include a high-water level alarm, which will alert building owners to overflow and wasteful operation of the filling controls. Also, submeters will be required for new cooling towers, boilers, most swimming pools, commercial kitchens, laundries, and gyms or spas. These submeters will help building managers detect leaks and malfunctions that now often escape notice for days or weeks.

Introduction 263 prohibits new installation of once-through cooling systems starting in 2011. These systems work by emitting their waste heat into potable water, which is then drained directly into the sewer system. Each ton of cooling in a once-through system uses 150,000 to 200,000 gallons of city water per year (at a cost $1,500-$2,000 in water bills). These once-through systems actually make no sense economically, since the water costs far more than the modest capital cost increment for a standard system that releases the waste heat to the air. However, to avoid excessive equipment costs in some constrained retrofit situations, replacement of existing installations is exempted as long as the replacement system does not use more water than the existing one.

Finally, Introduction 264 (Task Force proposal Health & Toxicity 20) improves access to drinking water. The law, which goes into effect July 2012, removes an existing code provision that permits bottled water vending machines to substitute for half the required drinking fountains in public assembly areas. It also requires new drinking fountains to include faucets for filling water bottles, and allows half the required fountains to be replaced by dedicated faucets for filling bottles.

These bills may never have been proposed were it not for the creativity and hard work of the Water and Building Stormwater Committee of the NYC Green Codes Task Force, including their input during the legislative process. Once again, we commend their efforts.

A great survey of the incredibly important efforts to restore Louisiana’s coastal wetlands.

The folks over at the ASLA’s blog, The Dirt, give a handy rundown of last week’s lecture by Frederick Marks on Human Responses to Green Design. Several fascinating subjects are covered but the one you should really keep your eye on is the notion of including “human performance”, along with energy and water, as part of the standard metrics by which we measure the success of a design.

Treating water as a precious resource is every bit as important as conserving energy. In the same manner that we have begun to explore the possibility of net zero energy, we need to move towards buildings that are net zero water users. Like energy, water use is terrifically complicated and concepts like Net Zero Water can help us get our heads around the subject and move the conversation forward.

A researcher in Philadelphia has launched a blog on the Net Zero Water concept.  Worth a visit.