Thursday, April 28, 2011
In this instance the RPA is a 100-foot buffer along both sides of the river and streams with perennial flow. Within the RPA allowed development is extremely limited in order to preserve a natural plant buffer that slows runoff, prevents erosion, and filters nonpoint source pollution. Though the river is at the bottom of my land, there are several small creeks in the woods that may or may not be perennial. It doesn’t really matter since I have no plans for the woods beyond spring cleanup of accumulated trash, using the woods as the location of my compost piles (the non RPA portion) and keeping the woods for its ambiance. When you site in the kitchen, the family room, in my office, or on the deck what you see is a park with trees and plantings ending at the woods edge. The protected watershed gives me my private yard; a special place that I hope will someday be magical.
Each spring I prepare my garden for summer, deadhead some of perennials (which maybe I should have done al little more aggressively last winter), cleanup the dead leaves and remove any dead plants. The incredibly harsh winter of 2009-2010 followed by the heat wave last summer killed off four shrubs and 6 evergreens. It was a sad and expensive loss that was compounded by the deer pulling several plants out of the ground. I have been trying to create a garden along the principals of green scaping. I am expanding the plantings in my garden, adding a few more trees and shrubs each year, replacing the losses and learning the principals and practices of green scaping and organic gardening. The EPA calls green scaping “the easy way to a greener, healthier yard.” Gardening is work. In the spirit of full disclosure the spring cleanup, edging, enlarging a bed, hauling in the compost, replacing plants and mulching has taken 38 man hours so far only about 8 of them mine.
In the woods soil and the organisms in soil recycle dead plants and leaves into nutrients for new plant growth. Plants that grow in the woods are adapted to the water, sun and soil available there. Maintaining a wide variety of healthy plants, soil organisms, beneficial insects and animals can keep many pests and diseases in check. The woods beyond the garden seem to do just fine. The idea of green scaping is to work with nature to have a low maintenance and healthier garden.
There are five principle of green scaping:
1. Build and maintain healthy soil.
2. Practice natural lawn care
3 Plant right for your site
4. Limit watering
5. Adopt a holistic approach to pest management
Soil is the very essence of life consisting of eroded rock, decayed organic matter, water and air and teeming with microscopic life. Soil is both the beginning and the end of the food chain. This is a beautiful concept from HRH Prince of Wales’ book “The Elements of Organic Gardening.” The soils in my neighborhood and my yard are described by the USGS as Balls Bluff Siltstone with a gravel, sand and clay type bedding plane. (That is the technical name for the flat plane, edged orange red rocks that are everywhere you put a shovel.) There is very little overburden, virtually no top soil. My first challenge is to build rich topsoil. Building topsoil is a long (and expensive) process. When I first read “The Elements of Organic Gardening” I was very discouraged by the scale, scope and manpower that the Prince of Wales put into his lands. It took me a long time to appreciate that the most important step was to build soil.
Though I have a nice pile of compost available each year to add to my garden, I have been using the compost to expand my planted beds each spring. Someday I would like to be able to top dress my lawn with compost when I aerate and over seed in the fall but that will have to stay in the someday category. The expense of aerating and over seeding the front lawn and the acre of land closest to the house is all that is in my soil building budget each year. However, the lawn is mowed with a mulching lawn mower that leaves the clipping on the lawn to recycle the nutrients in the grass cuttings back into the soil. I do not use fertilizer or pesticides or for that matter water the lawn. Though my lawn is environmentally friendly, it certainly is not great. I photograph my lawn and garden every year and I was very discouraged until I reviewed the pictures. The lawn is slowly improving. After surveying the neighborhood I am no longer the third worst lawn, I am clearly in the middle of the pack.
Choosing what to plant is very important, but even when I select plants that grow well in my region and allow for sun loving and shade loving I still have failures. There are always a few plants that do not survive the winter and the deer. I have a small group of evergreens that died out over the past two winters. On the other hand some plants are so successful that they need to be moved, split or pruned. Though I do not water my garden as a routine practice, I do water planting until they are firmly established. I have purchased watering tubes for the replacement trees and I am considering some organic Holly-Tone to help the new trees become established.
Finally, you need to adopt a holistic approach to pest and weed management. I do not use pesticides in my garden. The beds are weeded by hand. Last summer the weeding took about 6 hours a month to keep the beds clear of weeds- not exactly the EPA promised “easy way.” Weeding is the work of gardeners. The lawn is kept at 3 inches in hopes of building strong and deep roots that someday will choke out the lawn weeds. For now I have embraced dandelions as pretty and anything green growing in what passes for a lawn around here is considered good- crab grass, clover and other weeds. The sections of tall fescue are expanding adding lovely dark green to previously bare spots and interspersed in the lawn. Progress.
Monday, April 25, 2011
The maximum number of fowl allowed is proportional to the lot size. One bird unit per acre is allowed for properties of 1 to less than 5 acres, three bird units per acre for properties of 5 to less than 10 acres. There is no limit on the number of bird units allowed on properties greater than 10 acres. A bird unit is:
10 chickens (though only one rooster per acre) or
6 ducks or
4 turkeys, geese or pea fowl or
1 ostrich or emu
20 pigeons, doves, or quail
The new fowl regulations require coops or cages and runs on any lot with less than five acres and specifies construction standards and humane areas for each bird, distance from Resource Protected Areas (RPA) under the Chesapeake Bay Act, distance from well heads. In addition, waste management for surface and groundwater protection must be established using the new Prince William Soil and Water Conservation District guidelines. These guidelines should prevent (or at least significantly reduce) contamination of the groundwater, a major drinking water supply for the area, and prevent the backyard chickens from adding contaminated runoff to the Chesapeake Bay.
As our area has become more suburban, density has increased, along with the utilization of groundwater for domestic purposes and the density of septic systems. This suburban development has increased the suburban runoff and nutrient contamination to our groundwater and the Chesapeake Bay watershed. Virginia is under a federal mandate to reduce nitrogen, phosphorus and sediment contamination to the Chesapeake Bay. The federal pollution diet requires that Virginia reduce our non-point source pollution of nitrogen, phosphorus and sediment. The only responsible way the County Supervisors could allow property owners the right to have backyard chickens was to control the waste in a way that would not add to the nitrogen, phosphorus and sediment pollution. It was appropriate and necessary for them to leverage the resource of the Prince William Soil and Water Conservation District to develop guidelines for low impact backyard chickens.
The proposed zoning change to allow backyard chickens contain limited regulations of the micro poultry “farms” to manage the waste and location of coops according to the protective separation requirements of the septic regulations. This hopefully will ensure that best management practices will be adopted by the backyard micro farmers without being unduly burdensom.
You may also want to read a later article https://greenrisks.blogspot.com/2017/06/the-rules-for-backyard-chickens-in.html
Thursday, April 21, 2011
A world view accepting the interconnections among the nature and the society of mankind is a very ancient world view that appears in many indigenous and ancient civilizations. Only in the 20th century did large parts of society lose that understanding. Rachel Carson reminded us of that interconnection. Her book, Silent Spring, first appeared in serial form in the New Yorker and then as a best selling book in 1962. The science in the book may have been shallow, but her literary genius and emotional appeal created a movement. Followers flocked to Carson's cause which was rendered all the more powerful by her premature death in 1964 from breast cancer. The book's release was considered by many to be a turning point in our understanding of the interconnection between the environment and societal well-being.
In the 49 years since that time the environmental movement has reached middle age. The widespread acceptance of the validity of the environmental movement, which began in earnest in the 1950’s, followed by the first Earth Day in April 1970 and by the founding of the US EPA in December of 1970 established the environmental movement as mainstream. The current generation of young adults has grown up with the three “R” being “reduce, reuse, and recycle.” While society was embracing the environment, the leading edge of the environmental movement journeyed towards a broader concept: sustainability and sustainable development.
Since the late 1980s sustainability has been used more in the sense of human sustainability on planet Earth. One of the most widely quoted definition of sustainability and sustainable development is from the United Nations World Commission on Environment and Development commonly called the “Brundtland Commission.” They defined sustainability and sustainable development as:
"Development that meets the needs of the present without compromising the ability of future generations to meet their own needs."
In late 1983 Gro Harlem Brundtland, the former Prime Minister of Norway was asked by the Secretary-General of the United Nations to establish and chair the World Commission on Environment and Development, a special, independent commission convened to formulate "a global agenda for change." After three years the commission produced what is commonly known as "The Brundtland Report." Published in book form in 1987 as Our Common Future, the report addresses what it identifies as "common concerns," such as a population growth, lack of food security, dwindling biodiversity, and excessive use of polluting energy. Finally, the report lists "common endeavors," such as managing communally or society owned resources, making industry more efficient, maintaining peace and security while not suspending development or degrading the environment, and changing institutional and legal structures.
The Bruntland report has often been subject to criticism, on the grounds that many of its 'forecasts' proved to be inaccurate and in fact many of the causal assumptions were not studied. As the Development Education Program of the World Bank Institute (WBI) points out many of the relationships are just not measurable; and many of the goals are in conflict with each other. So what has survived of the Bruntland report is the first sentence. The Bruntland report should be viewed as a product of its time and its focus on inequalities between rich and poor should be seen in that context. Even in 1987 Brundtland Commission stated “Globally, wealthier nations are better placed financially and technologically to cope with the effects of possible climatic change. The world must quickly design strategies that will allow nations to move from their present, often destructive, processes of growth and development onto sustainable development paths.”
The World Commission on Environment and Development (Bruntland Commission) was followed in 1992 by the Rio Declaration on Environment and Development, (Rio Declaration) which was developed at the 1992 United Nations "Conference on Environment and Development," often called the Earth Summit. The document consists of 27 principals that range from youth mobilization to eradication of poverty to compensation for environmental impact and national environmental policies. The most lasting portion of that document was the “Three Dimension Concept” which coined the concept that sustainable development was a balance of three dimensions: • Environmental Protection • Economic Growth • Social Development
In 1993 President Clinton created the President’s Council on Sustainable Development, a panel of leaders from business, science and other areas. The committee was tasked with bringing together industry, environmental groups, and government agencies to form consensus on policy; and implement programs to promote sustainable development. They focused on programs to lower greenhouse gas emissions, and policies that might foster sustainable communities.
Still, common themes run through most definitions of sustainability. They usually deal with nature, the economy, society or, perhaps most often, all three together. Most are not about maintaining life precisely as it is today. They are about the rate of change, and about equity between generations or political groups. Many see sustainability as a continually evolving process. The World Conservation Strategy views sustainable development as integrating conservation with satisfying basic human needs, achieving equity and social justice, providing for social self-determination and cultural diversity, and maintaining ecological integrity.
The US EPA states “Sustainable development can be facilitated by policies that integrate environmental, economic, and social values in decision making. From a business perspective, sustainable development is accomplished by capturing system dynamics, building resilient and adaptive systems, anticipating and managing variability and risk, and earning a profit.” It sounds good, but I have no idea what that means in real life and how we apply the principals of sustainable living and development to our lives and our communities, but I note they were able to include the three dimensions from the Rio Declaration. All of these different organizations address different aspects and definitions of sustainable development, but all are vague and remain open to interpretation.
Monday, April 18, 2011
Suitable soil is necessary for successful wastewater treatment. The “percolation rate” is the rate at which water moves through soil. The acceptable rates are between one minute and one hour per inch of soil. Take either more or less time for the water to pass through your soil and the natural soil is unsuitable for treatment of the waste water. If the water moves too slowly through the soil the leach field will flood with contaminated, foul smelling water or the water will back up into the house. If the water moves too quickly thought the soil the water will not be adequately treated and contaminate nearby ground or surface water. Other types of septic systems are grouped together and called alternative on-site sewage systems, AOSS. One example of an AOSS is an aerobic system consists of a multi chamber tank or several tanks. After separation of solids in the first tank waste is forced through a filter into a second chamber or tank where air is pumped in to enhance aerobic bacteria which decomposes the organic material. The waste then flows into a third chamber or settling chamber which collects the bacteria and passes the liquid on to the leach field or drip field. Aerobic systems can remove more than 90% of the organic material and suspended solids within the tanks themselves, but require much more maintenance. Other type of AOSS include traditional septic tanks followed by treatment with tanks filled with peat, or sand mounds, or other soil absorption system that provide the secondary treatment.
In Virginia all AOSS are required to have a licensed operator maintain the system and be inspected at least annually. For more information on AOSS regulations and requirements see the Guidance Document from the Virginia Department of Health. Indoor water use in the typical single-family home is between 50-70 gallons per person per day. Septic systems are sized by bedrooms, which is an estimate of the number of people living in a home. However, even if the number of people living within your home is appropriate for the size of the septic system, you can still overload the system. Use too much water in a short period of time and the system will be overwhelmed. Each time the system is overwhelmed untreated sewage will leave the tank and begin to clog the leach field. If the amount of wastewater entering the system is chronically more than the system can handle, the wastewater containing raw sewage eventually backs up into the house or yard and creates a health hazard. By the time you can smell or see a problem, however, the damage to the leach field might already be done. Replacement of a leach field can run to the tens of thousands of dollars. So caring for your septic system not only cares for the earth but also cares for your wallet.
By limiting your water use and spreading out peak demands on the system you can reduce the amount of wastewater your system must treat. When you have your system inspected and pumped as needed, you reduce the chance of system failure. The US EPA’s Homeowner’s Guide to Septic Systems is a terrific basic guide to caring for and maintaining your septic system. Follow the Dos and Don’ts and your septic system may last for decades. Remember though, what goes into your septic system goes into the earth. Rethink the products you use to clean your house. Paint, solvents, gasoline, insecticides and poisons should never go down your drain. Every chemical you pour down your drain is buried in your yard. In a multitude of ways your yard is part of the earth’s yard. The functional lifetime of a traditional septic system is limited. The system is designed so that with proper maintenance it will last 20 to 30 years, under the best conditions. Many other factors can cause early failure of a septic system. Pipes blocked by roots, soils saturated by storm water, compacting of the drain field by parking vehicles or heavy objects on the top of the field, improper location, poor original design or poor installation can all lead to major problems. Septic systems and AOSS fail because they are abused, improperly maintained or just old. Remember that the entire functioning of a septic system is based on natural ecological cycles. It needs to be treated kindly and kept in balance. When a system is poorly maintained and not pumped out on a regular basis, sludge (solid material) builds up inside the septic tank, and then flows into the leach field, clogging it beyond repair. Excessive load from toilets, garbage disposal, putting grease, coffee grinds, kitty litter down the drain will shorten the life of and potentially overload the system.
Even with proper use and maintenance the system will wear out. Eventually, the soil around the leach field becomes clogged with organic material, forcing sewage upward into the yard or back into the house. Before that happens, however, there are warnings signs that you need to pay attention to.
Signs that a Septic System is Failing
1. Sewage backup in your drains or toilets. This is often seen as an unpleasant smelling black liquid.
2. Slow flushing of all or most of your toilets. Many of the drains in your house will drain much slower than usual, despite the use of plungers or drain cleaning products (which by the way should not be used with a septic system). Unfortunately, this is often gradual and goes unnoticed.
3. Liquid seeping along the surface of the ground in the back yard near the leach field. It may or may not have a noticeable odor associated with it. Lush green grass growing over the absorption field, even during dry weather or visual stripes in the grass texture and quality is often an indication that an excessive amount of liquid from your system is moving up through the soil, instead of downward, as it should. While some upward movement of liquid from the leach field is expected, too much could indicate major problems.
4. The presence of nitrates or bacteria in the drinking water well. This indicates that liquid from the system may be flowing into the well through the ground or over the surface. Annual water testing will indicate if you have this problem.
With alternative septic system assessing functionality is relatively simple for a qualified inspector (as required in Virginia). AOSS require maintenance to keep functioning properly and so AOSS regulations in Virginia require that these systems are installed with conservative horizontal set backs, are operated and maintained by a licensed operator, are sampled by a licensed operator every five years (with some older AOSS exempt from the sampling requirement), and an operating manual and records maintained on site. Remember that AOSS also need to have their primary tank pumped regularly and these expensive systems need to be treated with care.
Thursday, April 14, 2011
The 7.36 KW gross are equivalent to 6.2 KW PTC. I reserved 6 KW PTC Renewable Energy Rebate from Virginia and on completion of installation, inspection by the county, and sign-off by my power company, NOVC, I filled out all my paperwork, provided copies of permits, signed off inspections, invoices, technical information, contractor information and pictures of the installation, and meter and promptly (within 4 weeks) received my renewable energy rebate of $12,000 from Virginia. This payment is not taxable income, but according to the Commonwealth of Virginia, the Federal Tax instructions for form 5659, my accountant, Scott Price, and research performed by Andy Black, the payment reduces the cost basis of the solar system that the federal tax credit is calculated on. A tax credit is more valuable than an equivalent tax deduction because a tax credit reduces taxes dollar-for-dollar, while a deduction only removes a percentage of the tax that is owed. My 30% tax credit is calculated on $46,540 and was $13,962. Thus, from the original installation cost of $58,540 I subtract the Virginia Renewable Energy Rebate of $12,000 and the 30% tax credit of $13,962 and my total out of pocket cost for my solar system after the first year is $32,578. A rough estimate using the DOE model of my savings on electricity (I have an air heat exchanger) is $1,400 per year. That is slightly over a 4% return on my investment each year.
However, that’s not the final cost. The cost and return on a solar power system is based entirely on regulated incentives and there are more. The final incentive is the Solar Renewable Energy Credit or SREC. Each SREC is a credit for each megawatt of electricity that is produced. SRECs have value only because some states have Renewable Portfolio Standards, RPS, which require that a portion of energy produced by a utility be produced by renewable power. Utilities in some states can fulfill that requirement by buying SRECs from solar installation producers. It is a way for states to ensure that the upfront cost of solar power is recovered from utility companies (and ultimately from the consumers). Some states, like New Jersey and Maryland, require their utilities to buy SRECs only from residents of their states creating a closed market where the price is very high. Some states, like Virginia, have no current RPS requirement. Other states, like Pennsylvania allow their utilities to buy their RPS from any resident within the PJM regional transmission organization (at least for now). Still other states like California do not allow the purchase of SRECs to meet RPS requirements. I am currently selling my SRECs in Pennsylvania. SRECs in Pennsylvania have ranged from $180-$300 per megawatt hour recently. So, I could earn an additional $1,800-$3,000 a year for 15 years or as long as the demand for RPS lasts which ever is less. This past year I earned $1,045.94 in SREC income for the partial year that my panels were installed. This income needs to be reported on your tax returns. You report the total dollars received in SREC payments during the calendar year on Line 21 of the 1040 form-other income.
After the tax exercise and calculating my total return I was not feeling particularly excited about my solar panels and this was compounded by having nothing but trouble with the Enphase micro converter system that is sending a constant stream of error messages. Nonetheless, several service calls to the solar company identified the problem as a network and monitoring problem. The solar panels continue to work and produce power into the grid. The customer service for the installation company is virtually non-existent for the Enphase micro converter and the customer service at Enphase was virtually useless to me though I did buy another router to boost the signal of my internet.
Two days after filing my tax returns, I received my electric bill for $55.17 (compared to the $213.53 for the same month last year). That was a quick way to regain the joy with my solar system. Though, I have more solar panels than Ed Begley, Jr., my panels in Virginia do not have quite as many sunny (and not covered with snow) days as Ed’s panels in Southern California and in truth my multiple refrigerators and freezers and my air heat exchanger consume a lot of power. Only when my heat pump is operating within its most efficient range and cycle combined with the insulation and passive solar steps I have taken are my electric bills this low, but it still felt really good.
The effectiveness of a heat pump is based on the temperature difference between the source and the sink and which cycle it is in. Heat pumps are more effective for heating than for cooling if the temperature difference is held equal. This is because the energy used to power the compressor is largely converted to useful heat when in heating mode and released into the house as extra heat. During the cooling cycle, the condenser is normally outdoors, and the compressor's dissipated work is rejected rather than put to a useful purpose. When the temperature is below 48 degrees Fahrenheit or above 90 degrees the air source heat exchanger becomes much less efficient and my electric power use soars.
The most effective type of heat pump is the geothermal heat pump. Like all heat pumps it doesn't create heat by burning fuel. Instead, in winter it collects the Earth's natural heat through a series of pipes, called a loop, installed below the surface of the ground or submersed in a pond or lake. As you may have experienced in a cave, the temperature six feet beneath ground surface is cooler in summer and warmer in winter than the ambient temperature. Using this temperature as its source the geothermal heat pump can operate within its most efficient range at all times. In winter, fluid circulates through the loop and carries the heat to the house. There, an electrically driven compressor and a heat exchanger concentrate the Earth's energy and release it inside the home at a higher temperature. I have not been able to find any calculators of cost savings I might experience by converting to a geothermal heat exchanger, only the grand claims of the manufactures. The American Recovery and Reinvestment Act of 2009 extended the tax incentives under the Energy Policy Act of 2005 (EPACT) and eliminated the limit on the credit and extended the tax credit until 2016. Like solar panels, geothermal heat exchangers are eligible for an unlimited 30% tax credit and I have four years to save up to buy a geothermal heat exchanger to replace my air heat exchanger that should be near the end of its useful life by that time.
Monday, April 11, 2011
Thursday, April 7, 2011
Water stains can be caused by roof leaks, or condensing moisture. There's a lot of moisture generated inside homes. Bathrooms without exhaust fans or fans not vented to the exterior, leaking dryer vents, damp basements, kitchens and crawlspaces and basements can be the source of moisture in the in the home or attic. Improper roof ventilation or uneven insulation can create "cold spots" in summer or winter where moisture condenses to the point of dripping onto the ceiling or wet areas on the underside of the roof sheathing. Air conditioning equipment or heat exchangers in the attic can result in condensate dripping out of the system or off of the refrigerant lines or ducts.
Too much moisture in a home can lead to mold, mildew, and other biological growth. The presence of these molds can lead to a variety of health problems including allergies, asthma and more serious respiratory problems. In addition to health problems, excess moisture can lead to problems such as rot, structural damage, and paint failure and create a hospitable environment for pests and mold. Correcting and preventing moisture problems is a first defense against termites, mold, and structural failure. Any water damaged areas should be carefully inspected for mold. Mold growth is often found underneath water-damaged surfaces (for example, wallpaper and carpeting) or behind walls, floors, or ceilings.
Mold inspection and cleanup usually is considered a housekeeping task that is the responsibility of a homeowner (or landlord), as are roof and plumbing repairs, house cleaning, and yard maintenance. Failure to properly care for your home is negligence (and not covered by homeowners insurance). Typically, mold is not covered by insurance unless the water damage was caused by what insurance people call a covered peril such as a storm. Homeowners insurance would not cover damages from a flood including resulting mold. Flood insurance is a separate policy that you need to purchase. It would also not cover damage caused by a leaking pipe in your home, but would cover damage from rain getting inside the house through a hole in the roof or a broken window if the hole or the broken window was a result of a storm or extreme weather conditions. Remember hurricane damage is only covered if you have hurricane coverage. If the water damage was due to your ignorance or negligence, home insurance would not cover it. Pretty much, when dealing with moisture and mold, insurance is unlikely to cover the damage. Maintaining your home is your responsibility. Small water leaks of all kinds can be ignored for a long time, don’t. You need to be cautious and keep a regular check on all aspects of your home. Your home is probably the biggest purchase you will ever make, protect it.
If the routine inspection of your home identifies a mold problem you need to address it immediately. Mold will ultimately destroy the materials it grows on because it grows by consuming the organic matter. A small leak and small area of mold impact is fairly straightforward to deal with. Ignoring it will not make it go away, but allow it to flourish and expand. Signs of mold are discolored patches or cottony or speckled growth on walls or furniture or an earthy or musty smell or odor. People who suffer from mold-allergies will experience hay fever like symptoms all year long when in the house. Any water damaged areas should be carefully inspected for mold. Mold growth is often found underneath water-damaged surfaces (for example, wallpaper and carpeting) or behind walls, floors, or ceilings. If you smell something musty in your home, do not grab the air freshener; find the source of the smell. Look for moisture and water stains; feel for damp carpeting especially in basements feel for damp or soft wall board. If you find these you will probably find the mold beneath or behind it.
The process of remediating the mold is likely to disturb mold and release spores and potentially toxins into the air. To prevent this isolation of the work area, proper techniques of removal and protective clothing are necessary to minimize the risk spreading the mold spores and of making the situation worse. Actions that are likely to stir up mold include: breakup of moldy porous materials such as wallboard; invasive procedures used to examine or remediate mold growth in a wall cavity; actively stripping or peeling wallpaper to remove it; and using fans to dry items. This is why a professional mold remediation firm should be used when there are large areas to remediate or the potential to release large quantities of mold spores or toxins to other areas of the home exists.
Monday, April 4, 2011
Molds are neither plant nor animal, but fungi that can be found almost anywhere; they can grow on virtually any organic substance, as long as moisture and oxygen are present. Wet cellulose materials, including paper and paper products, (books, books and more books), cardboard, ceiling tiles, wood, and wood products, are particularly conducive for the growth of many types of molds. Molds grow by digesting and destroying these organic material. Many other materials in your home such as paints, tile grout, wallpaper, insulation, drywall, carpet, shower curtains, window shades, and upholstery, also serve as excellent locations for mold growth. Indoor molds are ubiquitous, but are not usually a problem unless there is a moisture problem.
The most common indoor molds are Cladosporium, Penicillium, Aspergillus, and Alternaria. However, Stachybotrys chartarum is a greenish-black cellulose loving mold that has gotten a tremendous amount of attention as the “toxic mold” of 2001 fame. That term is not accurate. While certain molds can produce mycotoxins, and are thus are toxigenic, the molds themselves are not toxic, or poisonous. After much research, the US Environmental Protection Agency (EPA) and the US Center for Disease Control and Prevention (CDC) and the California Department of Health Services (CDPH) and the public health community at large agree that allergic reactions to mold in buildings occur, particularly for sensitized persons. However, in the present peer-reviewed medical literature, there is no conclusive evidence that mold toxins in buildings cause any human health illness. Though there are case reports of symptoms caused by mold toxins; evidence is inconclusive. Breathing in mold or other dampness related bacteria may cause hypersensitivity pneumonitis, an uncommon disease that resembles bacterial pneumonia. In addition, mold exposure may result in opportunistic infections in persons whose immune systems are weakened or suppressed, have existing lung disease, or asthma.
After considerable research into this issue, scientists and the World Health Organization concluded in October 2006 that although recent studies have strengthened the evidence between living and/or working in a damp environment and increased risk for respiratory symptoms, the role of mold growth in these complex environments is still unclear. Damp buildings also encourage the growth of bacteria, dust mites and cockroaches, as well as degradation of wet building materials that can also release irritant chemicals indoors. Some or all of these chemicals or biological organisms may contribute to occupant illness. Thus, science based exposure limits for indoor molds cannot be established at this time. However, the presence and health risks of biological contaminants in indoor air are all caused by moisture which should be prevented or stopped as soon as possible.
In summary, Stachybotrys chartarum (Stachybotrys atra) and other molds may cause health symptoms that are nonspecific. At present there is no scientific evidence that proves a cause and effect relationship between Stachybotrys chartarum and a particular health symptom or condition. Reliable sampling for mold can be expensive, and standards for judging the level of mold exposure that is not acceptable or cannot be safely tolerated have not been established. So testing for any particular type of mold is a waste of money. It is not necessary to identify the species of mold growing in a residence, and CDC does not recommend routine sampling for molds. Currently, there is no air sampling or environmental test that can determine if mold found in buildings is producing toxins, nor can any blood or urine test establish that an individual has been exposed to Stachybotrys chartarum spores or toxins. To the susceptible population any mold that is seen or smelled is a potential health risk; therefore, no matter what type of mold is present, you should remediate the problem beginning with solving the moisture problem.
Molds can multiply by producing microscopic spores (2 - 100 microns in diameter) that easily float through window screens, attach to clothing or pets or is pulled into a home through a fresh air ducts. Mold spores are ubiquitous, but are not usually a problem inside a home unless there is a moisture problem. Molds only grow when there is moisture from water damage, excessive humidity, water leaks, condensation, water infiltration, or flooding. Constant moisture is required for mold to grow. Thus, your first defense against mold is keeping moisture out. As part of routine building maintenance, buildings should be inspected for evidence of water infiltration in ceiling or walls, water stains from small leaks, water damage around windows and doors, indications of small plumbing or other water leaks and visible mold. The conditions causing mold (such as water leaks, condensation, infiltration, or flooding) should be corrected to prevent mold from growing.
Well-designed, well-constructed, well-maintained building envelopes are essential to prevent and control moisture and microbial growth. Management of moisture requires proper control of temperature and ventilation to avoid excess humidity, condensation on surfaces and excess moisture. Ventilation should be distributed effectively throughout spaces. Specific Recommendations:
- Inspect your home for signs of moisture.
- Keep humidity level in house between 40% and 60%.
- Use air conditioner or a dehumidifier during humid months.
- Be sure the home has adequate ventilation, including exhaust fans in kitchen and bathrooms.
- Fix leaky plumbing, roof leaks and basement water infiltration as soon as possible.
- Dry wet or damp areas within 24-48 hours.
- Keep heating and air conditioning drip plans clean and flowing.
- Perform regular heating and air conditioning inspections to identify problems early.
- Use mold inhibitors which can be added to paints.
- Clean bathroom with mold-killing products.
- Do not carpet bathrooms.
- Remove and replace flooded carpets.
- Do not let foundations stay wet.
- Provide drainage and slope the ground away from the foundation.