Water Systems Management Renovation:
Making a Case for Grey Water Systems, Rainwater Harvesting and Green Infrastructure for N.Y.C.
Tyler Caruso
Fall 2009
Urban water systems have entered into a period of extreme stress and apparent failure, and in order to meet current and rising demands, will have to embrace significant changes in the near future. Water infrastructure consists of three complex and interconnected systems; drinking water, waste water and storm water. Drinking water systems are responsible for collecting, cleaning and delivering potable water. Waste water systems collect water after use, treat it and then reintroduce it as effluent water back into the watershed. The third system, storm water, is often combined with waste water, and its function is to transport storm water to a treatment facility. These systems face great obstacles created by urban development patterns, the policies and facilities that manage and control them and uncertain shifts in the global climate. This paper aims to prove that the current water infrastructure is both inadequate and inefficient; and in order to achieve a desirable long-term sustainable plan we need to undergo a paradigm shift. We need to engage solutions that move away from the traditional ‘end-of-pipe’ mentality, that was birthed from the inheritance of a large centralized grey infrastructure. We need to manage precipitation as close to where it falls as possible and use natural processes to our advantage in managing our storm water. As a country we need to demand incentives that encourage consumers to install water-efficient and Energy-Star rated fittings and appliances; change our behavior patterns to minimize wasting of water, and encourage technologies that improve the efficiency of water use.
History:
New York city’s watershed[1] is located upstate in the Catskills and Hudson River valley and covers approximately 1,900 sq ft. The watershed is divided into two reservoir systems: the Catskill/Delaware watershed west of the Hudson River and the Croton watershed east of the Hudson. This system delivers approximately 1.4 billion gallons of water every single day to over 9 million people in New York City, Westchester Orange, Putnam and Ulster counties (source 1). NYC currently relies on two enormous concrete-lined tunnels built in the early 20th century (creatively referred to as “Tunnel 1’ and “Tunnel 2’) to deliver its water supply. The United States Federal regulations protects water through The Clean Water Act, which regulates the discharge of pollutants into surface waters, and the Safe Drinking Water Act, which provides standards for potable water (source 2).
After water is used once, regardless of its application, it is considered waste water, and is required by law to be treated. Historically people relied on dilution from nearby water bodies to handle and transport wastewater away from densely populated areas[2]. By the mid 19th Century many municipalities in the U.S. had already built public sewer systems to help regulate street flooding but these systems were not used to transport sanitary waste. By the end of the century the U.S. began its tradition of, “looking to see what Europe was doing” in regard to their sewage. Coincidentally, the field of bacteriology emerged from the work of such scientists as Louie Pasteur and Jon Snow. This displaced the notion that dilution rendered wastewater harmless as the connection between wastewater discharges, polluted receiving waters and disease outbreaks became clear (source 3). As technology for urban watershed systems emerged, their implementation and management was shaped equally by financial and political constraints, as it was by health and environmental factors. The existing combined sewer systems (CSSs) remained because of their ability to centralize the collection of human and industrial waste. However the wastewater treatment plants (WWTPs) were originally designed and sized to treat sanitary waste, not a combination of sanitary wastewater and combined storm water runoff. This method of treatment was adequate during dry weather flow (DWP) periods, however during wet weather flow (WWF), the systems can become overwhelmed by the quantity of material. Once the volume reaches a certain level that exceeds the CSS’s handling capacity, they overflow raw sewage into the surrounding water bodies (as they were designed to do) (source 3). This system is still currently in place- and it wasn’t until the mid 20th Century that a comprehensive understanding of the potential pollution that overflows present was understood. In 1965 Congress finally passed the Federal Water Pollution Control Act, which admitted the need for regulation of CSO output (source 3).
CSOs as described by the US EPA,
“…consist of mixtures of domestic sewage, industrial and commercial wastewater, and storm runoff. CSOs often contain high levels of suspended solids, pathogenic microorganisms, toxic pollutants, floatables, nutrients, oxygen-demanding compounds, oil and grease, and other pollutants. CSOs can cause exceedances of water quality standards. Such exceedances may pose risk to human health, threaten aquatic life and its habitat and impair the use and enjoyment of the Nation’s waterways” (Source 3 section 1-3).
In many regions precipitation of as little as 0.10 inches can lead to a significant amount of storm water that enters into the CSSs, resulting in many CSO events annually. During the DWF periods, settling and build-up of solids occurs in the sewage pipes, until a surge of water from a storm purges the system. As a result, a large sanitary pollution load, referred to as the ‘first flush’, which contains levels of pollutants that greatly exceeds the normal amount are released over a short period of time (source 3).
“Many CSOs discharge into receiving waters in heavily populated urban areas. Their impacts include (but aren’t limited to) adverse human health effects, beach closures, fish survival effects, shellfish bed closures, aquatic life toxicity, and aesthetic impairment. Waterborne transmission is a common and fast way of spreading infectious agents to a large part of the population. Disease outcomes associated with waterborne infections often include hepatitis, gastroenteritis, as well as skin, wound, respiratory, and ear infections” (source 3 section 1-4).
CSO discharges also compromise the attainment of ‘fishable’ and ‘swimmable’ objectives set forth by the Federal Water Pollution Control Act. “New York City annually dumps some 27 billion gallons of raw sewage and polluted storm water, spewing from approximately 460 CSO outfalls, into virtually every water body surrounding New York City” (Source 14 page 4). The DEP submitted a series of plans to the New York State Department of Environmental Conservation (NYSDEC) cut out 11 billon gallons of raw sewage from being dumped- but it would still permit 18 billion gallons of raw to overflow annually. Also these DEP plans do not deal with polluted runoff that needs treatment that is discharged through separate storm sewers (source 14).
Communities have to better manage storm water in order to minimize flooding, erosion of stream channels and to avoid the use of CSOs. This task has been complicated because development in densely populated areas have resulted in large amounts of impervious surfaces that do not allow for rainwater to infiltrate the ground. This is commonly referred to as urban run off, which is a non-point source pollution, occurring over a vast areas stemming from varying land-use activities. The corollary to increased wet weather runoff is reduced dry weather stream flow. This condition results because impervious surfaces increase the speed of the precipitation flow towards stream channels, which doesn’t allow time for recharge into the soil, which supports the base flow of streams. This effect has been termed as producing “higher highs and lower lows” (source 4).
Storm water has traditionally been thought of as a problem that needs to be controlled. The rain comes down and runs across buildings and large areas of pavement, collecting oils and greases, pesticides, trace metals, pet feces, lawn fertilizers, particles sloughed from automobile brakes and a whole host of other pollutants. Urban runoff has become a major water pollution contributor, it is the number one source of diminishing water quality in surveyed estuaries and the third largest in surveyed lakes (source 6).
In order to deal with these pollutants the water needs to be treated- but the methods that have been in used over the past hundred years, have been proven to be ineffective. A new paradigm for urban water systems are in order- the “soft path” set out by the Rocky Mountain Institute’s Report: “21st Century Water Systems: Scenarios, Visions, and Drivers” (listed below), is a wonderful starting point.
| The Old Paradigm | The Emerging Paradigm |
| Human waste is a nuisance. It is to be disposed of after the minimum required treatment to reduce its harmful properties. | Human waste is a resource. It should be captured and processed effectively, and put to use nourishing land and crops. |
| Storm water is a nuisance. Convey storm water away from urban areas as rapidly as possible. | Storm water is a resource. Harvest storm water as a water supply, and infiltrate or retain it to support urban aquifers, waterways, and vegetation. |
| Build to demand. It is necessary to build more capacity as demand increases. | Manage demand. Demand management opportunities are real and increasing. Take advantage of all cost-effective options before increasing infrastructure capacity. |
| Demand is a matter of quantity. The amount of water required or produced by water end-users is the only end-use parameter relevant to infrastructure choices. Treat all supply-side water to potable standards, and collect all wastewater for treatment in one system. | Demand is multi-faceted. Infrastructure choices should match the varying characteristics of water required or produced by different end-users: quantity, quality (biological, chemical, physical), level of reliability, etc. |
| One use (throughput). Water follows a one-way path from supply, to a single use, to treatment and disposal to the environment. | Reuse and reclamation. Water can be used multiple times, by cascading it from higher to lower-quality needs (e.g. using household gray water for irrigation), and by reclamation treatment for return to the supply side of the infrastructure. |
| Gray infrastructure. The only things we call infrastructure are made of concrete, metal and plastic. | Green infrastructure. Besides pipes and treatment plants, infrastructure includes the natural capacities of soil and vegetation to absorb and treat water. |
| Bigger/centralized is better. Larger systems, especially treatment plants, attain economies of scale. | Small/decentralized is possible, often desirable. Small scale systems are effective and can be economic, especially when diseconomies of scale in conventional distribution/collection networks are considered. |
| Limit complexity: employ standard solutions. A small number of technologies, well-know by urban water professionals, defines the range of responsible infrastructure choices. | Allow diverse solutions. A multiplicity of situation- tuned solutions is required in increasingly complex and resource-limited urban environments, and enabled by new management technologies and strategies. |
| Integration by accident. Water supply, storm water, and wastewater systems may be managed by the same agency as a matter of local historic happenstance. Physically, however, the systems should be separated. | Physical and institutional integration by design. Important linkages can and should be made between physical infrastructures for water supply, storm water, and wastewater management. Realizing the benefits of integration requires highly coordinated management. |
| Collaboration = public relations. Approach other agencies and the public when approval of pre-chosen solutions is required. | Collaboration = engagement. Enlist other agencies and the public in the search for effective, multi-benefit solutions. |
(source 5)
The soft path calls for the use of diverse, decentralized green infrastructures to maintain the water supply, sanitation treatment, and regulate storm water runoff. In the following sections of this paper the use of grey water systems, rainwater harvesting and green infrastructure will be shown to help disconnect the input of CSSs in order to avoid CSO overflows. These methods use the natural hydrological system as a resource, enabling watershed soils and vegetation to become a tool in the management of storm water runoff. It also embraces a multifaceted diverse approach to waste water treatment, which utilizes the above systems to incorporate reclamation/reuse of water. We need to shift the emphasis away from ‘end-of-pipe’ solutions towards onsite reduction and management plans. Treatment facilities need to be sized and matched for use of the exact quantities and qualities of water that are required for different uses (i.e. not having treatment centers provide potable water that is to be used for landscape irrigation, toilet flushing and other places where scale-backs are deemed appropriate).
Run Off Management:
The current goal for U.S. cities should be to aim for infiltration (or secondarily delay/ detainment) of runoff from a two year, 24-hour storm, which is considered 2.50 inches of rain, on site. It is agreed by most hydrologists that storms of lesser quantity and greater frequency are responsible for most of the water quality and channel degradation problems we link with problematic urban runoff (source 4).
In the list below (which was based off a table in the “Re-Evaluating Storm Water the Nine Mile Run Model for Restorative Redevelopment”) some of the numerous green infrastructure techniques that are being used today in order to mange storm water onsite are presented:
• Tree plantings- Foliage and vegetation can absorb, retain and evaporate a large portion of rain that falls annually, trees typically planted in tree pits.
• Tree pit guards- Prohibiting tree pit guards that are flush with the surface of the sidewalk around the entire perimeter of the tree pit, which block the flow of storm water to the tree pit.
• Soil rehabilitation- Aeration, soil amendments and other techniques can increase the
infiltration rate of lawns. Certain plant species, by virtue of denser, deeper roots, can
further improve infiltration.
• Planting strips Require planting strips in higher-density residential areas and non-residential areas, except where determined to be infeasible.
• Surface infiltration basins. In some yards and many commercial landscapes, ponds, temporal “water gardens,” and other basins can be designed to gather site runoff and
detain it over varying periods of time.
• Vegetated swales. These features can infiltrate, attenuate, and treat runoff.
• Diversion of runoff from impervious surfaces. Pitch drainage from driveways, sidewalks, and other pavements onto adjacent vegetated soil where it can infiltrate, away from street
gutters.
• Grading- Require grading of any non-planted yard areas to direct runoff to the planted areas.
• Street narrowing and use of green ‘neck-downs’. Common now in new developments, narrow streets calm traffic, increase green space, improve property values, and reduce impervious area.
• Curb cuts and/or inlets (also known as trench drains) to allow runoff from the street to flow to tree pits and planting strips.
• Parking lot redesign. Creative layout that can incorporate “infiltration islands,” filter strips, and other storm water management features with no or little impact on the number of
parking spaces.
• Porous pavements. Selectively apply porous concrete, porous asphalt, unit pavers (stone,
brick, and concrete masonry), open-celled pavers, gravel, organic mulch, decks, and grates to appropriate locations and uses.
• Subsurface detention/infiltration chambers. Made of gravel or manufactured components, with varying depths and capacities of chambers that can be installed under lawns and pavements to retain large site run off volumes during a storm and encourage that water towards the subsoil in the following hours or days.
• Roof leader disconnections or down spout disconnection. Appropriate redirection of the leaders, re-grading of the landscape around a building, use of dry wells, and other techniques that can mitigate roof runoff without flooding basements.
• Cisterns. Some roof runoff can be captured in rain barrels or other cisterns and either
used for yard and garden watering, car washing, etc., or released to dry wells or other
infiltration systems once the storm passes.
• Green-roofs. A modern variant on the sod roof, with lower weight and easier handling
and maintenance, has been created and installed widely in Europe. Eco-roofs absorb
water and use evapo-transpiration, reducing the urban heat island effect and encouraging biodiversity and ecosystems
• Culvert daylighting. Reopened stream corridors can include space in the cross-section for
flood spreading and attenuation, permeable surfaces for infiltration, and diverse riparian
plantings.
• Site reconfigurations. In the redevelopment context, sites can be redesigned to reduce the
quantity of pavement, or density or ‘infill development’ can be increased to reduce the need for automotive transportation and the pavements it requires.
(Source 4 page 21)
Green infrastructure refers to techniques and systems that use the natural capacities of soil and vegetation to absorb and retain water, and to remove, amend and treat pollutants found in water. Green infrastructure has been long over-looked by cities favored instead for gray infrastructure. However the tides are changing, as we are having to face the ramifications of water pollution from CSO overflows that have lead to the degradation of our water. Cities such as Portland, OR, Philadelphia and Pittsburgh have emerged boasting the news of their efficiency, functionality and cost effectiveness. Portland, OR through a series of policy decisions has begun to readily introduce green infrastructure; using a new building code that requires onsite storm water management for all new construction projects (promoting and encouraging the use of green infrastructure techniques to do this). Also all new municipal buildings are required to have a green roof that covers 70% of the roof area.
Philadelphia is currently revising its storm water billing system in order to create a more transparent and equitable fee structure that accurately reflects the costs of managing storm water from each property. All new developments that cover 15,000sq ft of earth disturbance must, early on in the process, submit a storm water management plan. This has resulted in a switch from development on undeveloped natural areas to development on infill sites. Since 2006 the city has built-out over one square mile with green infrastructure features, that can handle most one inch storms. This new system has saved over $170 million dollars annually and also reduced over a quarter billon gallons of CSO overflows (source 15).
Philadelphia announced exciting news last week[3], its plans for,
“…. a $1.6 billion plan that would transform the city over the next 20 years by embracing its storm water - instead of hustling it down sewers and into rivers as fast as possible…. The idea now is to "peel back" the city's concrete and asphalt and replace them with plants - with rain gardens, green roofs, heavily planted curb extensions, vegetated "swales" in parking lots, and mini-wetlands….The proposal, which several experts called the nation's most ambitious, reimagines the city as an oasis of rain gardens, green roofs, thousands of additional trees, porous pavement, and more”. Most experts have agreed that the green techniques "are well-demonstrated,"…said the Natural Resources Defense Council's water expert, Nancy Stoner, "It's the scaling up that's new. That's what's really exciting!" (source 17).
Water Conservation:
There is a missing link in most American’s minds between how the water from our tap is delivered, the amount of energy used and the resultant green houses gases (GHG) emissions. The water system used in the U.S. is energy intensive.
NYC’s wastewater treatment plants (WWTPs) emit 17% of the total CO2 emissions per year. These plants also release a large amount of methane gas, one of the strongest GHG emission sources.
The major barriers to achieving wide spread water savings in the U.S. is not technology but the prevailing attitude that most Americans posses, the right to limitless amounts of potable water. This mindset coupled with an out dated pricing system that doesn’t adequately reflect the true cost of treatment, distribution and discharge, places water conservation out of most people’s thoughts. Americans use on average 80 gallons of water per person per day for household uses, but that number dramatically rises if outdoor irrigation is used. The numbers can be roughly 200 to 400 gallons of water used per person per day. This number is massive especially when compared to water poor countries like Mozambique, Rwanda, Haiti, Ethiopia, and Uganda that use 4 gallons or less per day (source 7). The benefits of water conservation are many and can be immediately accessible for utilities, consumers and the environment. The public, businesses and residents could experience energy cost savings, a reduction on their water heating bill, the possibility to eliminate the problem of overflowing cesspools or septic tanks, water cost savings and reduced cost to taxpayers for the public sector water and energy use. Utilities experience reduced peak power demands, reduced pumping, reduced wastewater treatment load and reduced capital costs. The environment stands to gain a minimized strain on its natural resources and reduced emissions of pollutants (source 6).
The Cleveland District Water supplies water to over 70 communities, with an average daily pumpage of 260million gallons per day (MGD). This requires approximately 2,400 kilowatt-hours per million gallons. If there was a 10% reduction in water consumption there would be a savings of 624,000 KWh/day or 227,760,000 Kwh/year. The EPA shows that 700,000,000 Kwh/year is enough to power 700 homes for a year (source 6 page 48).
In general water conservation techniques are easy to perform and have a low overhead. Water efficient appliances and fixtures are a great way to start. Installing a high performance showerhead can cost as little as $20 and can cut shower water use by 25-75% (showers make up 21% of the total residential water use). Another way to conserve is to make sure there are no leaking fixtures (leaky toilets are responsible for 5% of the total residential water use). The use of an efficient toilet (a 1-1.6gallon-per-flush) could cut indoor water use by 20-25%. This will achieve a savings of 15,000 gallons of water annually. Efficient faucets can also reduce indoor water use by 3-5%. You can reduce your washing machine’s water use by 30-60% by using a new horizontal axis machine, which equals a 7,000 gallon annual savings. Lawn watering can be reduced 100% by introduction of native drought tolerant species that do not require any mechanical irrigation[4] (source 8).
Other less widely excepted solutions to indoor water conservation are composting toilets, grey water systems and rainwater collection systems. In the following sections of this paper grey water and rainwater harvesting systems are put forward as an effective means to reduce CSO events and also manage storm water onsite.
Grey Water or Water Reclamation/Reuse:
Grey water is wastewater, which does not contain sewage, it is typically collected from a building’s sinks, showers, and laundry facilities. Grey water does not contain human waste products. The major sticking point that prevents most people from adopting grey water systems is the fear that grey water is unsafe. However in the US alone there are eight million systems with 22 million users, without a single documented case of grey water transmitted illness (source 18).
There are many reasons to install grey water systems; they are a very effective alternative when building sites have limited space for septic "black water" disposal and treatment, or for sites with slow soil percolation or other problems. A second reason that property owners install grey water systems could be that there is a shortage of potable water in dry areas where there are limitations on the water supply. A typical grey water system can save 50 to 100 gallons of water a day, or even more, depending on the system. Indirectly it also leads to less energy and chemicals bing used, due to the reduced amount of potable and wastewater that needs to be pumped and treated.
Systems are highly effective at purification in the upper, most biologically active region of the soil. This protects the quality of natural surface and ground waters. Also if homes produce more grey water than needed for specific plant needs it can help recharge the groundwater. Grey water enables a landscape to flourish where water may not otherwise be available to support plant growth. It also encourages the reclamation of otherwise wasted nutrients.
Water Reclamation not only reduces the initial withdrawal of water from the environment but it simultaneously lessens the water flow in CSSs. It is made very cost prohibitive in NYC (and maybe other cities in the US) because NYC building code requires that the water be treated back to potable water levels. Any deviance from that rule has to go through the DEP and is considered on a case-by-case basis. In order to attain a variance you have to submit your construction plans to the DEP; showing that it adheres to proper sanitation standards, prove it won’t back-up/over flow and that there is a by-pass to the system, which can be reverted to in the event there is an overflow.
The City of New York has Local Law 99, 205 which is an update to the plumbing code[5]- that requires any building in NYC that has a grey water system, needed be reviewed on a case by case basis by the Department of Health and the Department of Building. NYC is waiting on the state to make grey water rules/codes but the State DOH has not shown any interest in addressing this issue currently (source 20)[6].
There are only a handful of buildings in NYC that use grey water systems. The Solaire is the first green high rise residential building located in Battery Park. It has the ability to treat its wastewater on site. The Solaire has two green roofs that collect 70% of storm water and it filters out heavy metals and pollutants from excess runoff. This cleaned run-off water is collected in Solaire's basement cistern along with the building's grey water and is later used to irrigate nearby parks. It requires 50% less potable water than a conventional, residential high-rise building (Source 10).
New York City has seven LEED buildings that make up the Water Efficiency Sustainable Design pilot program (source 11). These buildings save an estimated 500,000 gallons of water per year, which make-up 43% of the water used in these buildings. The Queens Botanical Garden is a LEED Platinum building, it has a grey water system that collects water from the sinks, showers and dishwashers, and funnels it through a constructed wetlands. The gravel, sand and root systems of the plants remove pollutants before the water is pumped back to the visitor center where it is used to flush the low- flow toilets. This small wetlands is capable of recycling around 4,000 gallons of water per week (source 9). The Lion House Conservation, Brooklyn’s Children’s Museum, Glen Oaks Branch Library, Weeksville Heritage Center and Remsen Yard all use grey water systems in various capacities (source 11).
Grey Water Case Studies and Models- the Future Hope for NYC
Currently in PlanNYC Storm water Management 2008 Plan there is no mention of grey water. The plan focuses on “Blue Roofs”, when a roof is outfitted with catchment tank or cistern that can be used to detain water for several hours until the storm has passed. The plan acknowledges the EPA’s call for source controls through the use of green infrastructure. “The agency actively encourages regulated municipalities to reduce runoff volumes and sewer overflow events through the wide spread use of management practices that capture and treat storm water before it is delivered to ambient waters” (source 22). The Stormwater Management plan empahisis the use of PlaNYC’s green initiatives (million trees project, green streets, tax abatement for green roofs, additional wetlands in our Blue Belt system and many others), and a continued commitment to managing storm water onsite. It preposes to accomplish this mainly through zoning amendments that prohibit front yard pavings in private homes and public plazas and increased water conservation incentives and initiatives. However the NYC’s Stormwater Management plan neglects to follow suit after several other U.S. have set the example and that by using a variety of source controls and a widespread comprehensive green infrastructure, they have experienced a great reduction of CSO events. In the following sections other cities’ efforts are highlighted to make a case for NYC to adopt similar policies and plans.
Austin, TX:
In Austin, Texas sub-surface irrigation is required by the Department of Health for all grey water systems. The regulation of onsite wastewater disposal systems falls under the jurisdiction of the Austin-Travis Country Health Department and LCRA, and is governed by rules made by the State Legislator, the Texas Water Commission and the City of Austin. The rules that govern grey water systems are modified laws intended for septic system guidelines. The major modification is the location of the drainage field in the root zone of plants for irrigation and/or groundwater recharging and the allowance for a smaller lot size. In Austin grey water systems are quite popular, with a high occurrence of illegal systems (mainly from washing machines with direct lines being run outside for irrigation). The law states that a grey water system must be approved by the Austin- Travis Country Health Department.
“Ordinance #880310-H & I establishes regulations of individual septic tank systems and septic tank system use in subdivisions. These regulations are found in Chapter 12-4 of the 1992 Code of the City of Austin and govern the construction, inspection, and approval of all septic systems, grey water systems, and composting toilets within the jurisdiction of the City of Austin.
A section to this ordinance allows the Austin - Travis County Health Department to approve “Innovative Systems”. Innovative Systems are defined as those systems not specifically described in any technical reference found in Chapter 12 of the 1992 Code of the City of Austin, or issued by the Texas Water Commission, or in the LCRA’s Supplemental Standards to the Texas Department of Health Construction Standards for Private Sewage Facilities. The Innovative Systems section to ordinance #880310-H & I does not grant categorical approval to non sub-surface grey water irrigation systems. The regulation allows a case by case review of innovative approaches…The Health Department has a “cookbook” of acceptable septic system and grey water designs. Standard designs may be allowed in accordance with lot size and conditions such as slope. Any system outside of the “cookbook” typically requires submission by a registered Professional Engineer” (source 19).
There is a step by step procedure to gain a license for a grey water sub-surface irrigation system:
1- Apply for a permit from the Health Department and submitted a fee $200-300 depending on the system type
2- A percolation test will be performed by the Health Department (a fee of $50 will be assessed)
3- If passed, a permit will be issued and periodic inspections by the HD will be performed during installation.
4- A license will be issued after completion of proper installation
(source 19)
Arizona:
The state of Arizona is currently the leader in the U.S. for progressive grey water policies. The state takes a 3-tiered approach when monitoring grey water systems:
1) Tier 1 systems process less than 400 gallons per day and meet a list of reasonable requirements are covered under a general permit without the builder having to apply for anything[7].
2) Second tier systems either process over 400 gallons a day, or can not fulfill the list of requirements set forth in Tier 1, or are considered a commercial, multi-family, or institutional dwelling and will require a standard permit.
3) Third tier systems are systems that process over 3000 gallons a day. These systems are reviewed on a case-by-case basis. (source 18)
Victoria, Australia-
Victoria has a fairly comprehensive code of practice for onsite wastewater management that deals with grey water systems. The plan details varying options for dealing with wastewater in sewered and unsewered areas differently that treat up to 5,000 liters or 1,320 gallons per day. The code breaks up each scenario into several options:
I. In sewered areas more stringent conditions are applied to permanent grey water systems than the allowed use of grey water as a temporary supply during dry weather to water lawns and gardens. Onsite backwater recycling is not permitted where retriculated sewerage is available except in certain situations. A permanent grey water system must include:
1. An EPA approved treatment system
2. A diversion value that diverts grey water to the sewer if the grey water system production exceeds demand.
| Treatment | Single Domestic premises | Multi-dwelling/ commercial premises |
| Secondary Treatment 20/30[8] | Subsurface irrigation only | Subsurface irrigation only |
| Secondary Treatment and disinfection 20/30/10 | Subsurface and surface irrigation | Subsurface and drip irrigation only |
| Advanced secondary Treatment and disinfection 10/10/10 | Subsurface and surface irrigation, toilet flushing and washing machine | Subsurface and drip irrigation only And other uses if approved through the Australian Guidelines for Water Recycling. |
II. In unsewered areas there are three options and each level require a different standard of water treatment in order to meet code.
1-Recylcing grey water indoors only- Used for toilet flushing and/or cold water supply to washing machines with a minimum water quality level of 10/10/10 standard.
2-Recylcing grey water indoors and outdoors- Used in above ways and also outdoors for sub-surface (water quality of 20/30) and/or surface irrigation (water quality of 20/30/10)
3- Recycling grey water outdoors only- for sub-surface irrigation with a water quality of 20/30.
(source 22)
Philadelphia:
In Philadelphia’s “High-Performance Building Renovation Guide” under the Emerging Technology Strategies Section alternative wastewater treatment methods are mentioned (as opposed to PlanNYC 2030 which completely ignores the topic of grey water). Black water onsite treatment facilities are even mentioned. Philadelphia states that,
“Every gallon treated and reused on-site is diverted from municipal wastewater facilities. The City has less need to expand, repair, modernize and maintain these facilities, as well as the connecting sewer lines. The same applies to potable water facilities. The technique makes societal sense and is worth considering for municipal buildings” (source 13 Guide 12-6).
A possible way to implement grey water systems into NYC public housing:
In NYC there is great structural potential to retrofit NYC’s “ Tower in the Park” public housing to use grey water. “Towers in the Park” buildings are modernist high density public housing, where the building’s foot print is minimized and the majority of the lot is park or open space. The roof leader could be either piped so that it is floor by floor, which is the least ideal for a large grey water system retrofit. The roof leader could connect to the plumbing in the basement where it could be diverted into a storage tank with a UV filter and stored for landscape irrigation. Or the leader could run out into the street where it connects to the sewer. If the latter situation is present then there are several ways to think about water reuse. The actual pipe could be cut and the water could be daylighted[9] providing a variety of options, such as a biotope, the introduction of a wetlands or it could be stored in catchments tanks . Or the water could flow subsurface into in a shallow trench or French drain system to irrigate plantings .
Rainwater Harvesting:
Rainwater collection systems provide alternative water supplies for many household uses, such as, flushing toilets, irrigating plants or washing vehicles. Rainwater collection also relieves the load on the potable water supply while reducing the amount of volume in CSSs. Systems can range from a simple rain barrel to collect roof runoff, to very large cisterns which store water for onsite use during dry seasons or droughts.
Many cities have been promoting downspout disconnection programs, to help clean roof runoff from overloading the sewer system and wasting the water’s potential for irrigation. It is simple, effective, very inexpensive and easily implemented. Over 47,000 buildings in Portland have disconnected downspouts, which results in one billion gallons of roof runoff form entering the CSSs. Portland pays homeowners $53 for each downspout they disconnect themselves, or they will disconnect it free of charge. The most common method of residential disconnection is a cut to the downspout above the sewer standpipe, and attach an elbow and extension piece to direct the runoff to a discharge point that is at least five feet away from any property lines, six feet from basements and two feet away from crawl spaces and porches. The city does require a permit to disconnect a residential downspout, unless working with the Environmental Services Downspout Disconnection Program. In all cases it requires a permit if the downspout is redirected to an on-site storm water management facility such as a cistern (source 12).
In NYC Habana Outpost restaurant in Fort Greene, Brooklyn practices rain water harvesting. The restaurant directs rainwater from its downspout into a storage tank where it passes through a UV filter and is piped into the building and used to flush the toilets. It has both a toggle system so if the tank is running low the system automatically switches to use tap water, and, a spill-way/overflow on the catchment tank with an external downspout in the event that the water level rises past capacity.
If NYC followed Portland, OR or Philadelphia’s lead and utilized downspout detachment we could see a large amount of rainwater diverted from single or two-family houses never entering the CSSs. In Brooklyn brownstones usually form a ring around the block and have a central green space or courtyard-like space in the middle. This housing formation provides an excellent opportunity for rain harvesting and also presents a problem. The ring formation essentially forms a solid wall around the block and in NYC, unlike Portland or Philadelphia, the downspouts on buildings are usually located in the back of the property, where access from the street is not possible without granted entry through a private entrance. While there is an obvious access issue it could urge NYC to engage with the public and encourage public-government partnership in multiple ways.
Conclusion:
We have to look beyond end-of-pipe retrofits and renovations to the current water infrastructure, where monitoring and regulation serve only as reactionary measures to problems, and the surrounding ecosystems are disrupted and displaced. We have the opportunity to use creative ways of affecting long-term goals of sustainability, vastly improving water qualities beyond that decreed in the Federal Clean Water Act. We need to revisit and examine existing ordnances and policies in order to remove any potential constraints that would impede innovation. Any policies that restrict the use of soils, vegetation, and microorganisms to regulate water flows and remediate pollution need to be reviewed and removed immediately. Society has to be made aware of the limits of the existing systems and a partnership must be forged that encourages the implementation of source controls and onsite management through green infrastructure and the adoption of conservation principles.
Appendix A-
“Section 10 of the septic design regulations discusses the procedures for evaluating, installing, approving other septic system types besides those already discussed in detail here. This document uses the New York State wastewater treatment standard for individual household septic systems (Appendix 75-A) to provide an example of state regulated design and installation of both conventional tank and leach field septic systems and alternative septic system designs, including raised septic systems, septic mound systems, intermittent sand filter septic systems, and evaporation-transpiration septic systems” (source 16).
REGULATION(S): Appendix 75-A, Wastewater Treatment Standards - Individual Household Systems, Statutory Authority: Public Health Law 201(1)(1) (1 December 1990).
COMPOSTING TOILETS: 75-A. 10 Other Systems. (b) Non-Waterborne Systems. (1) In certain areas of the State where running water is not available or is too scarce to economically support flush toilets, or where there is a need or desire to conserve water, the installation of non-waterborne sewage systems may be considered, however, the treatment of wastewater from sinks, showers, and other facilities must be provided when non-flush toilets are installed. The Individual Residential Wastewater Treatment Systems Design Handbook gives more detail regarding composting toilets.115 The State Uniform Fire Prevention and Building Code [9NYCRR Subtitle S Sections 900.1(a) and (b)] requires wet plumbing (i.e., potable water plus sewerage) for all new residences. In accordance with Section 900.2(b), minimal required plumbing fixtures may be omitted for owner occupied single family dwellings if approved by the authority having jurisdiction. Health Department approval for said omission(s) shall be fully protective of public health and be in general harmony with the intent of Section 900.1 (i.e., provide satisfactory sanitary facilities). In some areas of the state where available water becomes insufficient to economically use flush toilets (i.e., even those with only 1.6 gallons per flush) or where a need or desire exists to conserve water, use of non-waterborne systems may be justified.116 Composters: These units accept human waste into a chamber where composting of the waste occurs.117 Composters accept only toilet wastes and kitchen food scraps coupled with supplemental additions of carbon-rich bulking agents such as planar shavings or coarse sawdust. Household cleaning products should not be placed in the unit. Failure to add adequate bulking agents or maintain aerobic moisture can result in the pile becoming hard (and difficult to remove) or anaerobic. The composted humus contains numerous bacteria and may also contain viruses and cysts. Residual wastes (i.e., the composted humus) should be periodically removed by a professional septage hauler. If a homeowner chooses to personally remove the composted humus, it should be disposed of at a sanitary landfill or buried and well mixed into soil distant from food crops, water supply sources and watercourses. The humus comprises an admixture of recent additions and composted older additions and should be disposed of accordingly. Humus disposal sites shall meet Table 2 separation distances for sanitary privy pits.118 These units shall be installed in accordance with the manufacturers instructions. The units shall have a label indicating compliance with the requirements of NSF Standard 41 or equivalent. Only units with a warranty of five years or more shall be installed.119
GRAYWATER: systems shall be designed upon a flow of 75 gpd/bedroom and meet all the criteria previously discussed for treatment of household wastewater.120 The treatment of household wastewater is regulated by 75-A.8. Subsurface Treatment. (a) General Information. All effluent from septic tanks or aerobic tanks shall be discharged to a subsurface treatment system. Surface discharge of septic tank or aerobic effluent shall not be approved by the Department of Health or a local health department acting as its agent.121 CONSTRUCTED WETLANDS: There is no official state policy regarding constructed wetlands. It is doubtful that the state or county health departments would approve them.122
(source 21)
Appendix B-
Model Gray Water Ordinance
for Tier One Simple Residential Gray water Systems
May 9th, 2008 Oasis Design
This document is inspired largely by the Arizona and New Mexico state gray water codes—See http://oasisdesign.net/greywater/law/. This ordinance provides for a single statewide permit allowing all gray water systems that meet the requirements below. No inspection or fees are required. Tier 2 systems—ones that don’t meet all the requirements below—must be individually permitted and inspected. Tier 3 regulation is for high flow systems, which are subjected to intensive engineering and environmental review.
Definitions
“Gray water” means wastewater that originates from residential clothes washers, bathtubs, showers, and sinks, but does not include wastewater from toilets.
A. A Tier 1 Reclaimed Water General Permit allows private residential direct reuse of gray water for a flow of less than 400 gallons per day if all the following conditions are met:
1. Human contact with gray water and soil irrigated by gray water is avoided;
2. Gray water originating from the residence is used and contained within the property boundary for household gardening, composting, lawn watering, or landscape irrigation;
3. Surface application of gray water is not used for irrigation of food plants that have an edible portion that comes in direct contact with gray water;
4. The gray water does not contain hazardous chemicals derived from activities such as cleaning car parts, washing greasy or oily rags, or disposing of waste solutions from home photo labs or similar hobbyist or home occupational activities;
5. The application of gray water is managed to minimize standing water on the surface, for example, by splitting the flow, moderate application rates, and generous mulching;
6. The gray water system is constructed so that if blockage, plugging, or backup of the system occurs, gray water can be directed into the sewage collection system or onsite wastewater treatment and disposal system, as applicable (except as provided for under 10, below). The gray water system may include a means of filtration to reduce plugging and extend system lifetime;
7. Any gray water storage tank is covered to restrict access and to eliminate habitat for mosquitoes or other vectors. Untreated gray water should be stored as short a time as possible—in any case, less than 24 hours;
8. The gray water system is sited outside of a floodway;
9. The gray water system is operated to maintain a minimum vertical separation distance of at least five feet from the point of gray water application to the top of the seasonally high groundwater table (excepting that gray water systems are allowed where they would be relieving loading on a septic system in a high groundwater area).
10. For residences using an onsite wastewater treatment facility for black water treatment and disposal, A) the use of a gray water system does not change the design, capacity, or reserve area requirements for the onsite wastewater treatment facility at the residence, and ensures that the facility can handle the combined black water and gray water flow if the gray water system fails or is not fully used. Alternatively, B) the gray water system shall be designed with two valved zones, each of which can accommodate the full, expected gray water volume. Providing the gray water system passes a flow test in each zone, the capacity of the on-site system may be reduced, or in the instance that an approved composting toilet system is present, eliminated;
11. Any pressure piping used in a gray water system that may be susceptible to cross connection with a potable water system clearly indicates that the piping does not carry potable water;
12. Gray water applied by surface irrigation does not contain water used to wash diapers or similarly soiled or infectious garments unless the gray water is disinfected before irrigation; and
13. Surface irrigation by gray water is only by flood or drip irrigation. Spray irrigation is not allowed. Containment within horticultural basins or swales is encouraged for flood irrigation;
14. It is required that kitchen sink water be applied subsoil in chambers of sufficient volume, or contained within a rat-proof outlet shield;
15. Gray water diverter valves should be downstream from traps and vents in plumbing that leads to septic or sewer.
B. Towns, cities, or counties may further limit the use of gray water described in this Section by rule or ordinance.
(source 18)
Appendix C
Arizona- R18-9-711. Type 1 Reclaimed Water General Permit for Gray Water
A. A Type 1 Reclaimed Water General Permit allows private residential direct reuse of gray water for a flow of less than 400 gallons per day if all the following conditions are met:
1. Human contact with gray water and soil irrigated by gray water is avoided;
2. Gray water originating from the residence is used and contained within the property boundary for household gardening, composting, lawn watering, or landscape irrigation;
3. Surface application of gray water is not used for irrigation of food plants, except for citrus and nut trees;
4. The gray water does not contain hazardous chemicals derived from activities such as cleaning car parts, washing greasy or oily rags, or disposing of waste solutions from home photo labs or similar hobbyist or home occupational activities;
5. The application of gray water is managed to minimize standing water on the surface;
6. The gray water system is constructed so that if blockage, plugging, or backup of the system occurs, gray water can be directed into the sewage collection system or onsite wastewater treatment and disposal system, as applicable. The gray water system may include a means of filtration to reduce plugging and extend system lifetime;
7. Any gray water storage tank is covered to restrict access and to eliminate habitat for mosquitoes or other vectors;
8. The gray water system is sited outside of a floodway;
9. The gray water system is operated to maintain a minimum vertical separation distance of at least five feet from the point of gray water application to the top of the seasonally high groundwater table;
10. For residences using an onsite wastewater treatment facility for black water treatment and disposal, the use of a gray water system does not change the design, capacity, or reserve area requirements for the onsite wastewater treatment facility at the residence, and ensures that the facility can handle the combined black water and gray water flow if the gray water system fails or is not fully used;
11. Any pressure piping used in a gray water system that may be susceptible to cross connection with a potable water system clearly indicates that the piping does not carry potable water;
12. Gray water applied by surface irrigation does not contain water used to wash diapers or similarly soiled or infectious garments unless the gray water is disinfected before irrigation; and
13. Surface irrigation by gray water is only by flood or drip irrigation.
B. Prohibitions. The following are prohibited:
1. Gray water use for purposes other than irrigation, and
2. Spray irrigation.
C. Towns, cities, or counties may further limit the use of gray water described in this Section by rule or ordinance.
(source 18)
Works Cited
1- EPA. “New York City Watershed”. http://www.epa.gov/Region2/water/nycshed/
2- “Liquid Assets Community Tool Kit”. Penn State Public Broadcasting liquidassets.psu.edu/outreach/community_toolkit.html
3- EPA. “Combined Sewer Overflow (CSO)”. http://www.scribd.com/doc/1836711/Environmental-Protection-Agency-cso
4- Collins, Timothy, Richard Pinkham, Bruce Ferguson and the Rocky Mountain Institute. “Re-Evaluating Storm water the Nine Mile Model for Restorative Redevelopment”. 1999.
5- Pinkham, Richard and the Rocky Mountain Institute. “21st Century Water Systems: Scenarios, Visions, and Drivers”. August 1999
6- Rocky Mountain Institute. “Cuyahoga Valley Initiative: A Model for Regeneration. “Using Water Wisely”. April 2004.
7- Streeter, April. “We Use How Much Water? Scary Water Footprints, Country by Country”. Treehugger. 24 June 2009. http://www.treehugger.com/files/2009/06/we-use-how-much-water.php”
8- Rocky Mountain Institute. “Water Efficiency for Your Home- Products and Advice Which Could Save Water, Energy and Money”. 3rd Edition. 1995.
9- Beal, Heather. “Distinct and Demonstrative”. GreenScene. March 2009.
10- Green Roofs for Healthy Cities. “Project: Solaire Building, New York, NY”. June 2006. http://www.greenroofs.org/index.php/grhccommittees/287?task=view
11- NYC Department of Design and Construction. “Sustainable Design Projects”. 2009. http://www.nyc.gov/html/ddc/html/design/project_3.shtml
12- Environmental Services City of Portland. “Downspout Disconnection”. July 2006. http://www.portlandonline.com/bes/
13- Phila.Gov. “High-Performance Renovation: Water Management- Philadelphia High-Performance Building Renovation Guide”. Guide 10. www.phila.gov/pdfs/PhiladelphiaGreenGuidelines.pdf
14- S.W.I.M. “Street Tree Zoning Testimony” Dec 19th, 2007. swimmablenyc.info/wp.../swim-testimony_street-tree-zoning.pdf
15- Managing Wet Weather with Green Infrastructure. “Case Studies” http://cfpub.epa.gov/npdes/home.cfm?program_id=298
16- Friedman, Daniel, “Greywater or Gray Water Systems as Components of Alternative Septic Systems for Difficult Sites”. 2009. http://www.inspect-ny.com/septic/altgreywater.htm
17- Bauers, Sandy. The Philadelphia Inquirer, “Breaking Ground with a $1.6 Billion Plan to Tame Water”. 27 Septemeber, 2009. http://www.philly.com/inquirer/front_page/20090927_Breaking_ground_with_a__1_6_billion_plan_to_tame_water.html?page=2&c=y
18- Oasis. Grey Water Policy Center http://www.oasisdesign.net/index.htm
19- Sustainable Sources.com. Grey Water Irrigation http://greywater.sustainablesources.com/
20- Email with Margot Walker from DEP
21- Web of Life. “The Humanure Handbook” http://weblife.org/humanure/appendix3.html#ny
22- EPA. “Victoria Code of Practice- Onsite Waste Water Management”. epanote2.epa.vic.gov.au/EPA/publications.nsf/.../$FILE/891.2.pdf
23- The City of New York. “PlaNYC: Sustainable Storm Water Management Plan 2008”. 2008.
[1] An area of land where water from rain or snow met drains downhill into a body of water- streams, rivers, lakes and oceans.
[2] Other methods of waste disposal included backyard privies vaults and cesspool systems (source 3).
[3] The plan is still awaiting the EPA’s approval.
[4] If you cannot live without a certain species you can use grey water for irrigation and avoid the use of potable water for landscape irrigation while reducing the potential for CSO outflows- this is described in detail later on in this paper.
[5] Please refer to Appendix A for the full text on Regulation(s): Appendix 75-A, Wastewater Treatment Standards - Individual Household Systems, Statutory Authority: Public Health Law 201(1)(1) (1 December 1990).
[6] Please refer to Appendix B for a model grey water ordinance created by Oasis Designs.
[7] Please refer to Appendix C for the Law for Tier One Systems in Arizona.
[8] A water quality standard indicating an effluent water quality of less than 20mg/lBOD and 30mg/L suspended soils. And 20/30/10 is 20mg/lBOD and 30mg/L suspended soils and E.Coli less than 10cfu/100ml.
[9] Daylighting refers to the restoration of a buried stream or drainage way that was previously buried or contained in a culvert back to the surface. There are many benefits such as improving hydraulic capacity by slowing runoff and allowing for infiltration, it can cut costs that culverts place on centralized storm water systems, improve water quality resulting in the creation of a riparian habitat and they can revitalize surrounding neighborhoods (source 5).
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