January 24, 2008 Issue
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Classified Chestnut Hill Local Don't Miss an Issue, Tell us what you see or Winner of Two |
Zoning Reform: You will not be surprised to learn that swimming or fishing in the Delaware River is hazardous to your health. It will continue to be hazardous until the city can undo the damage done to the Delaware River and its watershed over centuries of heedless urban development. At a meeting of the Zoning Code Commission on Jan. 9, those in attendance heard a presentation on this subject by Howard Neukrug, director of watersheds for the Philadelphia Water Department. He told a story of the degradation of the Delaware watershed that led us to this sorry state. It is a long history of heedless development, badly designed sewers, ignorance of and/or disregard of environmental consequences. In the question period following the presentation it became clear that Neukrug’s presentation was a powerful wake-up call for most of the audience. In addition to laying out a troubled history of mismanagement, the presentation also included a thoughtful plan for undoing the harm that has been done and showed some intriguing design and policy recommendations that both Mayor Nutter and City Council will want to carefully consider when the Zoning Code Commission sends them a reform bill. Why bother, you may ask? Rivers that flow through cities have always been polluted. Why should citizens of Philadelphia spend large sums of money to clean up the Delaware? The simple answer is that we are required to do so by federal law whether or not we have any interest in swimming or fishing in the river. But the presentation also illustrated a host of other current water management problems that have immediate impact on the quality of life in Philadelphia and of future problems that, if left unsolved, could have damaging economic consequences for the city.
Two Rivers Can the Delaware River be cleaned up? It appears that it can over an extended period of time. Consider the history of the Schuylkill. When my wife and I moved to Philadelphia in 1960, no one would willingly swim in the Schuylkill. At that time the bottom of the Schuylkill was known to be coated with industrial sludge from the mills upstream in Manayunk, Conshohocken, Norristown and Phoenixville. Now, 48 years later, it is clean enough that my daughter is happy to swim in it every year along with hundreds of other women competing in the annual SheRox women’s triathlon. It is important to point out that swimming in the Schuylkill is only thinkable today because the city bought up the land that we now know as Fairmount Park to protect Philadelphia’s drinking water supply in the early 19th century. That deed remains one of the great acts of enduring environmental stewardship by city officials. And we must also credit the Commissioners of Fairmount Park who have since resisted repeated attempts by developers to encroach on the park. I believe Fairmount Park still enjoys the distinction of being the largest urban park of any city in the nation and surely is, by all measures, the greatest free recreational resource available to the citizens of Philadelphia.
A brief history of water in Philadelphia With the notable exception of Fairmount Park, it has been the practice of Philadelphians over the past 300 years to gradually transform William Penn’s “greene countrie towne” from a pastoral landscape to a modern urban hardscape. In the process they have paved over the absorbent surfaces of fields, woodlands, gardens and dirt roads and put in their place the impervious surfaces of buildings, highways, streets and parking lots. As the construction of the modern city evolved, the management of stormwater changed from direct infiltration into the earth, where it replenishes natural ground water reservoirs, to collecting it from roofs and all the other impervious surfaces and carrying it directly to rivers through the sewer system, with little concern for the polluting of rivers and the loss of valuable filtration, purification and storage functions of natural ground water recharge. As the city’s growth exploded in the 19th century, when Philadelphia became the industrial capital of the nation, a vast network of sewers was built that we still use today. The sewers were designed to carry both stormwater and wastewater to rivers as quickly as possible. In those days drinking water was taken from the protected portions of the Schuylkill, treated at the waterworks and stored in a reservoir on the plateau where the Philadelphia Museum of Art now stands. As ever more buildings, highways, streets and parking lots were built in the 20th century, stormwater runoff exceeded the capacity of the antiquated sewers to handle the growing volume. Today Philadelphians are experiencing serious problems of water management, as Neukrug made clear.
Antiquated sewers Although parts of the city that were built up after World War II (the Greater Northeast, for example) have separate sewer lines for stormwater and wastewater, known as storm sewers and sanitary sewers, 75 percent of Philadelphia’s sewers are the old combined sewers that carry both stormwater and sanitary waste. There are two overriding defects in these antiquated sewers: (1) they do not now have the capacity to handle heavy storms and (2) they intermingle stormwater and wastewater. As often as 50 times a year, on average, rain events exceed the capacity of these sewers and the sewage treatment facilities that they normally pass through. On those occasions the contents of the sewers, both stormwater and raw untreated sewage, must be diverted directly into the rivers. This is what water engineers refer to as a “CSO” or combined sewer overflow. It is bad enough that the Water Department has to discharge raw sewage into the rivers 50 times a year. It is even worse if you live in parts of Center City, Northern Liberties or South Philadelphia where residents in some neighborhoods find raw sewage backing up through their own sewer laterals and flooding their basements. Unfortunately, Neukrug explained, the cost of building a whole new set of parallel sewer pipes to separate waste water from stormwater is in the billions of dollars and is therefore financially not feasible for the foreseeable future.
A glimpse of future Philadelphia water management As the audience was wondering how on earth the city would recover from this environmental disaster, Neukrug launched into a presentation of the Water Department’s plan for the future of water management in Philadelphia entitled “Clean Water?…Green City.” He cited the following three plan goals: “(1) unite the city with its water environment; (2) create a green legacy for future generations, and (3) incorporate a balance between ecology, economics and equity.” The plan adopts a new approach for stormwater management that will temporarily hold it on site to allow it to: infiltrate, evaporate or be reused. In short, it aims to restore what was lost over centuries of heedless urban development. In water management it appears that everything old is new again. He then illustrated a wide variety of methods, materials and systems to accomplish those objectives that included the following: • Disconnecting rain leaders from the sewer system to allow on-site infiltration. • Installing rainwater collection systems that reuse collected water for landscape watering, car washing or even for flushing toilets. • Creating rain gardens in shallow topographic depressions in the landscape where stormwater can be filtered, stored and infiltrated into the ground. • Creating bio-retention gardens along sidewalks and streets. • Creating bio-retention structures that are a part of buildings. • Creating underground infiltration structures such as seepage beds or larger recharge storage beds under the porous pavement of play yards or parking lots. • Creating planted open swales or channels used to direct water along the surface of the ground so that stormwater is slowed, cleaned, absorbed into the ground, or evaporated. • Using porous pavements and crushed stone paving as a substitute for solid concrete or bituminous paving. • Installing green (vegetative) roofs that are effective in retaining and evaporating stormwater on the roof as well as protecting and extending the life of the weather roof beneath it. When someone in the audience asked where in Philadelphia one could see a green roof, Neukrug answered, “There is one two blocks away at Friends Center at 15th.”
Friends Center Last summer, Friends Center installed a green roof on the flat roof of its three-story office building at 15th and Cherry streets. It consists of eight varieties of sedum planted in 4 inches of soil mixture over a plastic drainage grid to which the plants’ roots anchor themselves. Sedum is a hardy plant that is drought resistant and will grow to a mature height of about 6 inches. It is a model for what can happen on roofs all over the city. Friends Center has also recently awarded a contract to construct a rainwater collection system. The center will use the collected rainwater to flush toilets instead of using expensively treated drinking water for the same purpose. There are two benefits that the center will enjoy when this system is operating: its water bill will be reduced by a substantial sum and it will be making a contribution to the reduction of combined sewer overflows. Readers who are interested in seeing other examples of the items listed above can go to the Web site of the Water Department at www.phillyriverinfo.org and find the Stormwater Management Guidance Manual to see pictures, designs and construction guidelines for all of the structures and systems listed above. Readers should understand that these new methods of conserving water would not all be optional. New construction projects will have to demonstrate that the plans comply with code regulations current at the time of the application. The Stormwater Management Guidance Manual is an excellent guide for you, your architect or engineer. Readers inclined to make their feelings known on this subject can do so in many ways. Most effective are letters and e-mails to Mayor Michael Nutter and to City Council members. They can also attend Zoning Code Commission meetings and informational sessions, which are open to the public. The commission’s scheduled meetings and sessions are posted on its Web site at www.zoningmatters.com. Finally, they can get on the commission’s mailing list by sending an e-mail request to Karen Chin at karen.chin@phila.gov.
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