As an industrial hygienist it came as a surprise that the American Lung Association recently ranked Bay Area air quality among worst in nation for air pollution and particulates. Unhealthy levels of pollution were found in numerous parts of the country, but the San Francisco Bay Area was ranked sixth in the list of most polluted areas in the country.
Not only does Bay Area air quality vary dramatically from county-to-county, but the degree of separation between counties is dramatic. For instance the following counties received an “F” grade indicating unhealthy levels of pollution:
What Bay Area counties have the best air quality?
While these Bay Area Counties ranked very well for air quality, receiving an “A” grade from the American Lung Association:
That is as dramatic a continuum as you can imagine. This in part shows how much microclimates, impacts of climate change and road traffic, and wind patterns of the Bay Area impact local air pollution. San Mateo county was given a “B” by the American Lung Association, and Solono was given a “C.” These grades apply toward “high ozone days,” and an entirely different set of grades is available for “particle pollution.” There are differences between the two sets of data. For example, Marin County gets a “C” when it comes to particle pollution but an “A” when it comes to high ozone days.
If you’re considering purchasing a new building or want an existing building or site tested for air pollution, Healthy Building Science offers expert industrial hygiene services including air quality testing for particulates, VOCs, aldehydes and more. If you’re concerned after learning that Bay Area air quality is among worst in nation get a free quote for an air quality inspection and air quality testing. We service all of California and focus primarily on counties surrounding the Bay Area.
Before you reach for the pesticides, bug spray, or call the exterminator, consider that once you’ve sprayed, pesticide residues can remain years later. Luckily, there are resources to help inform you whether you want to use it in the first place and what to do after-the-fact to limit exposure and clean up pesticide residues.
There is little data on concentrations of pesticides found inside homes, but the studies that do exist indicate that interior pesticide residues are the norm rather than the exception.
Another 2008 study measured pesticide residues within public housing dwellings in Boston, Massachusetts. Pesticides were detected in all of the homes including banned or restricted use products.
Pesticides will break down over time
This breakdown time is called the “halflife.” Half-lives can vary widely based on environmental factors. The amount of chemical remaining after a half-life will always depend on the amount of the chemical originally applied. This process occurs more slowly inside leaving the chance of residues for a longer period of time. The pesticide DDT is an extreme example of a long half-life. DDT was banned from the U.S. in 1972 but it and its decomposition products can still be found in soil samples today, 45 years later.
All pesticides for sale in the country must be registered with the U.S. Environmental Protection Agency (EPA). In the registration process, the EPA assesses potential human health and environmental risks by reviewing ingredients, data from studies, intended uses, and storage and disposal practices, among many other aspects. If data arises at a later date regarding the safety of the product, the pesticide can have its registration withdrawn and the pesticide will no longer be legal for sale in the U.S.
The EPA has a cooperative agreement with Oregon State University, which operates The National Pesticide Information Center (NPIC). This center provides objective, science-based information about a variety of pesticide-related subjects, including pesticide products, recognition and management of pesticide poisonings, toxicology, and environmental chemistry. NPIC also lists state pesticide regulatory agencies, and provides links to their Web sites.
Organizations dedicated to informing the public on pesticides
Beyond Pesticides (BP) provides the public with useful information on pesticides and alternatives to their use. With this information, people can protect themselves and the environment from the potential adverse public health and environmental effects associated with the use and misuse of pesticides.
BP has created a database tool to access current and historical information on pesticide hazards and safe pest management.
For technical resources, the National Institute of Health, U.S. National Library of Medicine maintains databases on toxicology, hazardous chemicals, environmental health, and toxic releases. TOXNET is a toxicology data network with information on pesticides, among other chemicals.
The Pesticide Action Network (PAN) Pesticide Database is a one-stop location for toxicity and regulatory information for pesticides. The database and website are updated and enhanced by Pesticide Action Network North America (PANNA).
New Pesticide Regulations
In addition to the persistent residues, exposure to airborne pesticides is a risk, especially in farming communities. The California Department of Pesticide Regulation is currently working on rules that will restrict farmers from spraying pesticides within a quarter mile (0.4 kilometers) of public K-12 schools and licensed daycare centers from 6 a.m. to 6 p.m. during the school week. The new regulations take effect Jan. 1, 2018 and apply to crop dusters flying over fields, air blasters spraying orchards and fumigants along with most dust and powder pesticides that could be blown onto school grounds by the wind.
The link between the effects of air pollution on cardiovascular health and lung diseases like asthma are well established, but a new study finds high levels of particulates in the air pollution effects mental health. The negative effects may be attributed to behavior changes of people living in polluted areas, such as spending less time outside, or leading more sedentary lifestyles which can lead to psychological stress or social isolation.
While pollution consists of many components, this study focused on measurements of fine particulate matter, which is produced by car engines, wildfires, fireplaces and wood stoves, and power plants fueled by coal or natural gas. Fine particulate matter (particles less than 2.5 micrometers in diameter or PM2.5) is easily inhaled, can be absorbed into the bloodstream and is considered of greater risk than larger particles.
Monitoring Air Pollution Effects
The heavy Bay Area commute traffic, truck traffic, industry, and oil refineries all contribute to elevated PM2.5 and other pollutants. There are numerous resources to help identify when exterior pollution levels are elevated so that we can limit out exposure.
The Office of Environmental Health Hazard Assessment (OEHHA) developed CalEnviroScreen 3.0 to help identify communities disproportionately burdened by multiple sources of pollution and with population characteristics that make them more sensitive to pollution. Pollution burden as calculated by Office of Environmental Health Hazard Assessment OEHHA
Air Pollution Effects Higher Inside Your Car Than Outdoors
A 2017 study measured air pollution levels inside cars during morning commutes in downtown Atlanta, GA. The levels measured were up to twice as the roadside sensors. The study measured PM2.5 and oxidative byproducts of PM2.5.
The chemical composition of exhaust apparently changes very quickly, so roadside sensors may not accurately convey the real exposure. Additionally, sunshine heats pavement which causes updrafts that bring pollution higher into the air, to drivers’ breathing zones.
Here this Oakland Map displays the varying levels of carbon black measured by a Google Street View vehicle equipped with air monitoring equipment.
How to Protect Yourself From Rush Hour Air Pollution
While you are driving, you can protect yourself to a degree by keeping windows closed and the ventilation off while idling at stop lights and stuck in stop and go traffic. Another study looked at particulate concentrations in three size ranges (PM10, PM 2.5, and PM1.) that entered the cabin of vehicles driving in stop and go traffic. The course particles (PM10 – PM 2.5) are assumed to come from road abrasion and tire and brake wear while PM 2.5 and smaller are assumed to come from vehicle emissions.
The study found that the most effective way to keep particulate pollution out of the vehicle was to turn off the ventilation fan and close windows while delayed in traffic. Car ventilation systems were typically much more effective at removing the larger particles from the air than the finer, PM 2.5 particulates, thereby allowing fine particles in to the cabin even if windows were closed but fan on. They did find having the fan on recirculate prevented pulling the particulates into the car when in traffic delays.
Lately we’ve heard a lot about the heavy metal lead in school drinking water across California. The reason we’re hearing about these schools finding lead in their drinking water is because schools are now required to test for lead. We have known for a long time that lead poses significant health concerns, especially to children. The growing bodies of children and infants absorb more lead than the average adult and can result in irreversible damage to development.
New Legislation for School Drinking Water Standards
There are no Federal regulations for requiring testing for lead in school drinking water and childcare facilities, except for those that operate their own public water system, such as a well. California has recently passed legislation to address the lack of testing occurring in our public schools, thereby identifying lead sources exposure. As of October 13, 2017 new legislation AB746 adds Section 116277 to the Health and Safety Code that requires the State Water Resources Board to work with educational agencies improve the quality of drinking water in public schools serving kindergarten through 12th grade and preschools and child day care facilities located on public school property.
The California Water Resources Board lays out their plan and provides additional information here on lead in school drinking water.
The bill requires schools constructed before January 1, 2010 served by community water systems, such as public utilities like EBMUD or SFPUD, to test for lead in the potable water system of the school site before January 1, 2019. Schools can make a request for testing to the public water system any time prior to November 1, 2019.
If the testing finds lead in school drinking water that exceeds 15 parts per billion (ppb), then the school or school district must notify all parents and guardians of impacted students. Additionally, the school will shut down all sources where the excess lead levels may exist. Additional testing may be required to determine if all or just some of the school’s fountains and faucets are required to be shut down.
Action Steps: Lead in School Drinking Water
School districts are taking measures to protect students when testing identifies lead in school drinking water in one or more fixtures above the regulatory action level of 15 ppb:
Turn off water source to fixture
Notify school community
Provide bottled drinking water as necessary or requested
Repairing, updating or removing fixtures
Guidance on how to flush the faucet(s)
Written instructions and resources
Test results for lead in school drinking water are trickling in now and individual school districts are publishing the results of testing on their websites.
OSHA has issued two standards (“rules”) to minimize exposure to respirable crystalline silica. One rule applies to construction trades, and the other for general industry and maritime workplaces. This blog focuses on the new OSHA Silica Testing requirements for the construction industry. September 23, 2017, kicked off enforcement for most provisions of the OSHA Silica Rule for Construction.
The new rule requires silica air quality testing – but there’s one big loop hole. Contractors who decide not to comply with the new rule may be subject to fines up to $12,675; $12,675 per day for failure-to-abate; and $126,749 for a repeated or flagrant violations. This is why contractors are talking about this rule.
Why is there an OSHA Silica Testing Rule?
According to OSHA, those who inhale very small crystalline silica particles are at increased risk of harmful diseases, including:
Silicosis, an incurable lung disease that can lead to disability and death;
Chronic obstructive pulmonary disease (COPD); and
This means that every road crew you see should be using different protocols than just two months ago. We should start seeing more respirators on street crews.
OSHA Silica Rule will Change How We See Road Crews
What’s New in the OSHA Silica Standard?
Previously the Permissible Exposure Level (PEL) for respirable silica was 100 µg/m3 for an 8-hour time weighted average (TWA). The new OSHA Silica standard establishes an 8-hr TWA PEL of 50 µg/m3, half the old PEL, so it’s no wonder contractors are concerned and calling for silica air testing. In addition to testing requirements, “all construction employers covered by the standard are required to:
Establish and implement a written exposure control plan that identifies tasks that involve exposure and methods used to protect workers, including procedures to restrict access to work areas where high exposures may occur.
Designate a competent person to implement the written exposure control plan.
Restrict housekeeping practices that expose workers to silica where feasible alternatives are available.
Offer medical exams—including chest X-rays and lung function tests—every three years for workers who are required by the standard to wear a respirator for 30 or more days per year.
Train workers on work operations that result in silica exposure and ways to limit exposure.
Keep records of workers’ silica exposure and medical exams.”
The OSHA Silica Testing standard requires employers to:
Quantify concentrations of silica that workers are exposed through air quality testing.
Set an action level of 25 μg/m3 (micrograms of silica per cubic meter of air), averaged over an 8-hr day.
Protect workers from respirable crystalline silica exposures above the permissible exposure limit of 50 μg/m3, averaged over an 8-hr day.
Use dust controls to protect workers from silica exposures above the PEL.
Provide respirators to workers when dust controls cannot limit exposures to the PEL.
What is “Respirable Silica” and are My Workers at Risk?
According to OSHA, “Respirable crystalline silica – very small particles at least 100 times smaller than ordinary sand you might find on beaches and playgrounds – is created when cutting, sawing, grinding, drilling, and crushing stone, rock, concrete, brick, block, and mortar. Activities such as abrasive blasting with sand; sawing brick or concrete; sanding or drilling into concrete walls; grinding mortar; manufacturing brick, concrete blocks, stone countertops, or ceramic products; and cutting or crushing stone result in worker exposures to respirable crystalline silica dust…”
This means that most construction crews – especially concrete, stoneworkers, and demolition trades – are at risk and covered by the new rule. HBS suggests all contractors engaged in these standard construction activities hire an industrial hygienist and do their due diligence. Get silica air quality testing so you know where you stand.
One Big Loophole in the OSHA Silica Testing Rule:
If you follow “Table 1” measures you are not required to quantify silica exposure levels, AND are not subject to the PEL.
According to OSHA, “Table 1 matches common construction tasks with dust control methods, so employers know exactly what they need to do to limit worker exposures to silica. The dust control measures listed in the table include methods known to be effective…”
So if you’re very confident in your compliance professionals and team you can wing it and follow Table 1, but if you don’t dot your I’s and cross your T’s you may be subject to serious penalties. We suggest you get the OSHA silica testing done so you know where you stand and can demonstrate you’ve done your due diligence.
Far more people have been impacted by dust and smoke than fires themselves. If you were directly impacted by fires you should read Cleaning After Fire. For others in the region who have been more directly impacted by dust and smoke from fires, please consider these tips to minimize health impacts from poor air quality.
Dust and smoke contain chemicals and minerals that are dangerous to every living organism, including our pets and livestock. Check the EPA’s AirNow site for day-to-day general updates in your area. Pay particular attention to air quality reports during a fire if you:
have a heart or lung disease, such as heart failure, chronic obstructive pulmonary disease, emphysema or asthma.
are an older adult, which makes you more likely to have heart or lung disease than younger people.
care for children, including teenagers, because their respiratory systems are still developing, they breathe more air (and air pollution) per pound of body weight than adults, they’re more likely to be active outdoors, and they’re more likely to have asthma.
have diabetes, because you are more likely to have underlying cardiovascular disease.
are pregnant, because there could be potential health effects for both you and the developing fetus.
Inside: Dust and Smoke Getting In Through Cracks, Gaps & Ventilation
When outside air quality is bad you should minimize infiltration into the building.
Keep windows and doors closed.
Air seal large cracks and gaps around doors, windows, electrical and plumbing penetrations, etc. It’s long been a mantra of the high-performance building industry to “build tight and ventilate right.” Now is the time if you haven’t already. In the short-term you may simply use tape over larger areas, or plastic and tape over large openings.
Shut off outside air intakes for forced air systems. This may include temporarily covering crawlspace vents, incoming air ducts for HRVs/ERVs and central forced air systems. [NOTE: Contact your HVAC professional to make sure it’s okay to block these vents. Doing so – on some units – may increase pressure and burn out a fan.]
Some ventilation systems are designed to filter outside air. These systems may continue operating IF they do not noticeably worsen indoor air quality.
If possible, minimize use of exhaust fans such as those in bathrooms and over stoves, and don’t forget the clothes dryer is a large “vacuum” which results in significant outside air infiltration. This recommendation must be weighed with other factors, and some may not find the tradeoff worthwhile.
Hayward Score – Breathing Well During Wildfires
Outside: Dust and Ash Collects On Horizontal Surfaces
SAFE: Protect yourself and others from injury during and after restoration. Injuries after the disaster is over- from chainsaw accidents, cuts, electrical shock, sprains and falls, burns and other accidents- are all too common. Damaged buildings or homes are dangerous. You can avoid injuries and deaths with the preparations and tips in this guide.
DRY: Dry our or remove wet materials as quickly as possible. Dampness supports mold, bacteria, and pests, creating an unhealthy living space. That’s why it’s so important to properly dry the home out as soon as possible and keep it dry.
CLEAN: Remove debris, silt and grime with safe and effective cleaning methods. Damaged structures can have hidden dangers. Follow the methods in this guide to restore a truly clean and healthy home.
Protecting Yourself from Dust and Smoke
So now that you’ve done the above, how do we protect ourselves from smoke and dust indoors?
When it’s really dusty or you’re doing dust-generating work like cleaning, playing, moving furniture or boxes, you should consider wearing a mask to reduce fine particle inhalation. A typical “dust mask” does little to reduce fine particulates. A rated N95 mask is suitable and recommended for most DIY situations. If you have a beard – you’ll need a full-face respirator which are considerably more expensive and effective.
Clean using best practices for minimizing aersolization of fine particulates:
Wet-wipe and discard used rags. Do not dry dust with a featherer or anything like that.
Mop instead of sweeping. Wet mopping will capture more fine particulates and capture them in the water. Sweeping creates massive amounts of airborne dust.
Use a True-HEPA vacuum on carpets, floors, couches, beds, etc. Vacuum only when you’re just about to leave the space for some time. Vacuuming, even with a HEPA vacuum, will generate significant dust in the air. Leaving right after you vacuum allows that fine particulate to settle out of the air. Vacuuming a bedroom right before bed is no bueno.
Hire a professional if odors or visible dust feels overwhelming or health-threatening.
Run central ventilation fans in recirculation mode. This process – even with standard residential air filters – has been found to successfully remove fine particulates from the air.
Use a plug-in HEPA air purifier or scrubber 24/7, but especially during and after cleaning and while sleeping.
Most of the above comments were about managing dust (“fine particulates”) and smoke. Smoke smells are more tricky and worthy of a follow up blog. Smoke smells from fires can linger on building materials. Common approaches include applying a liquid-applied vapor barrier over materials or using Ozone indoors. There are pros and cons of each approach, and there are other options to discuss. Our advice is to first focus on the dust and then tackle the smoke smell next.
The October 2017 California Fires in Northern California were devastating. Northern California will be dealing with the death and destruction of recent wildfires for years. The immediate life-safety concerns about fire are obvious and frightening, but what many don’t realize is that returning to fire damaged buildings is also hazardous. Cleaning after fire is part of recovery, but done wrong this activity may do more harm. If you’re returning to a fire damaged community follow these fire restoration tips to reduce your health risks.
After you have dealt with the initial raw emotions of fire loss, after you have contacted your insurance company and relatives and emergency personnel that are worried about you, it is time to cleanup and rebuild. FEMA has a checklist for “returning to normal” after a fire. If hiring professionals is not in the budget or you want to get back home before the pros show up, read these tips for cleaning after a fire.
Immediate Threats When Cleaning After Fire
These basic measures may save your life when you return to cleanup after a fire.
Do not reenter a fire stricken area or building unless a professional has verified it is safe to enter. Fires may reappear and you don’t want to be stuck in the danger zone. Do not go around police/fire barricades or ignore evacuation orders.
Do not approach downed power lines or attempt to work around electrical wires.
If the structure has been significantly impact and there are any concerns about the structural integrity of the building, do not enter until an expert or structural engineer okays the building.
Do not enter areas with standing water. There may be hidden dangers in the water.
Less known and more rarely considered are the long-term health effects that may result from cleaning after fire damage. Modern US buildings are full of chemicals and dangerous materials. Most of the threats are in the form of smoke, dust and particulate inhalation and ingestion. Read these tips for minimizing long-term health risks from cleaning up after a fire. Thanks to Bill Hayward and his team at Hayward Score for helping create this list:
Air out your home when air quality improves. Sites such as the EPA’s California Air Now may have relevant day-to-day information on outdoor air quality.
Spray areas lightly with water and clean using damp cloths. Direct ash-filled water to ground areas and away from the runoff system. Discard cleaning cloths after use.
If you must vacuum, do so with genuine HEPA filters or use a high-quality shop/industrial vacuum outfitted with a high-efficiency particulate filter and a disposable collection filter bag. Some ash may contain asbestos, dioxin and heavy metals, so do your best to not stir it up again. Special attachments can be used to clean ash from gutters, so that it will not blow back over outdoor spaces. Use care when changing filters on devices since fine particulates will probably be released back into the air.
If you are using a broom or mop, sweep gently so you don’t aerosolize ash. Do not use a leaf blower because it will spread fine particulate everywhere and be hazardous. Wet-mopping is better than sweeping. Dispose of used mop heads.
Avoid skin contact with ash, and no one with heart or lung conditions should handle ash cleanup.
Remind yourself often to put people before property! Make safety your top priority.
Wear personal protective equipment (PPE), including protective clothing and a NIOSH approved respirator, every time you set foot in a damaged or moldy building.
Assess structural stability and hidden hazards before you enter. A professional inspection may be needed.
Prepare a plan for site work (supplies and methods), make a map (disposal and clean-up site layout), and review insurance policies and disaster assistance resources.
Go slow when pumping out water, then act fast to dry out and remove mold. Read, copy and share the DIY Mold Removal Guidelines sheet from the Rebuild Healthy Homes guidebook.
Always remove wet insulation and foam padding, even if the surface looks dry and clean.
Assume lead-based paint and asbestos are in homes built before 1978 (unless verified not present). Be mindful that disturbing such materials increases the hazard.
Control dust, capture debris and contain contaminants – with wet methods, drop cloths, debris bags, HEPA vacuums and workers trained in safe work practices.
Check credentials and hire only licensed and insured contractors, Lead-Safe Certified Renovators and certified asbestos professionals. Examine qualifications of mold remediation, fire and water damage restoration and other professionals. Check with your local contractor licensing agency, permit office and health department for requirements and lists.
Restore for more than before! Install hazard-resistant materials, connectors and building systems. Include energy saving and healthy home improvements.
Environmental Compliance Testing Protects Occupant Health
The word “compliance” may set our freedom loving hearts on high alert. Most Americans tend to push back when anyone tries to limit our personal liberties. But when it comes to our environment, compliance testing is necessary and can help expand our freedoms – Freedom from fear of drinking lead and heavy metal laden water, or breathing in silica dust, or eating food contaminated with viruses and bacteria.
There are many ways to measure and analyze toxins in our environment, but the Environmental Protection Agency’s (EPA) sole mission is to protect human and environmental health. The EPA still provides the strongest most actionable way to measure pollutants in our environment. The EPA gives Industrial Hygienists the tools to measure compounds whose concentration levels may be considered high risk. Compliance testing for Air, Water, Soil, Dust and Bulk materials is used to protect humans and other species from being exposed to certain pollutants. The EPA sets the standards for measuring the level of lead in the water or silica dust in air.
The Occupational Safety and Health Administration (OSHA) is the regulatory body created by congress 1970 that enforces the standards and will determine the Personal Exposure Levels (PEL’s) that are acceptable for these contaminants for workers that are exposed for 8hrs a day.
As industrial hygienists, we’ve found some companies are proactive when it comes to the protection of workers health, but others are only prompted to investigate as a result of occupant complaints and OSHA regulations.
Compliance testing is the methodology used to ensure a company is actively engaged in protecting employee health and well-being. So, even though compliance testing may be considered a stick and not a carrot – it serves the greater good by helping keep our most valuable resource (human resource) safe, healthy and free of illness.
OSHA is proactive in helping companies meet compliance and provides many resources such as the compliance assistant specialists.
Next Generation Compliance Testing
The EPA states – As our environment changes and we learn more about how pollutants affect our health the EPA is launching new system for improving compliance testing. This next generation of compliance testing consists of five interconnected components, designed to improve the effectiveness of this program and consist of the following:
Design regulations and permits that are easier to implement, with a goal of improved compliance and environmental outcomes.
Use and promote advanced emissions/pollutant detection technology, so that regulated entities, the government, and the public can more easily see pollutant discharges, environmental conditions, and noncompliance.
Shift toward electronic reporting to help make environmental reporting more accurate, complete, and efficient while helping EPA and co-regulators better manage information, improve effectiveness and transparency.
Expand transparency by making information more accessible to the public.
Develop and use innovative enforcement approaches (e.g., data analytics and targeting) to achieve more widespread compliance.
So even though the word “compliance” may trigger a “push back” response, it is a necessary tool to protect the health and well-being of all citizens. Be proactive and not reactionary – get a free quote for compliance testing today.
San Francisco Water Supply, New Chemicals & Ground Water Testing
For the first time in nearly nine decades, San Francisco is blending local groundwater with Hetch Hetchy Reservoir water, sourced from over 167 miles away. For some, this change has been hard to swallow as San Francisco residents have long held bragging rights to exceptional Sierra Nevada snow melt. Possibly a victim of its own successful PR, the San Francisco Public Utility Commission (SFPUC) now faces the challenge of educating residents to the addition of groundwater to their drinking water. Ground Water Testing may solve part of the puzzle.
Foodies Cheer SF Ground Water Quality Distinctive Taste
Food critics from the San Francisco Chronicle declared the difference in taste to be small. “It’s more distinctive in a good way,” said taster and former Chronicle wine critic Jon Bonne. “It tastes like what you want spring water to taste like.”
Most SF residents do not realize that historically only 85% of the water supply is sourced from the Hetch Hetchy Reservoir in Yosemite National Park, the rest comes from 5 local reservoirs right here in the Bay Area. The blend percentages may vary depending on the time of the year and other operational factors. The combined reservoir system is called the Hetchy Hetchy Regional Water System.
Last year, some residence became keenly aware of the local reservoir blend when the SFPUC added more water from the San Antonio Reservoir to the mix. Complaints of unpleasant earthy, musty odors and flavors poured in. Through ground water testing, the cause was found to be a harmless algae byproduct called geosmin. The utility stopped adding water from San Antonio and switched over to add water from San Andreas reservoir in Millbrae.
This incident, combined with national news of lead contamination in Flint, has left some people concerned about changes that may impact San Francisco’s water quality. Groundwater, aka, well water, contains many minerals, including calcium, magnesium, sodium and bicarbonate. Hetch Hetchy water does not because it has been filtered along the slick granite slopes of the Sierra Nevadas. While these minerals are benign, nitrates, on the other hand, can make people sick at high levels. According to the SF Chronicle, It is possible that source of the nitrates is from leaky sewage pipes and fertilizers. The utility tests for about 180 chemicals and scans for a wide range of pesticides have returned negative.
Map of Blended Ground Water
Variations in elevation throughout San Francisco will determine who gets the new blended water. This map shows which streets will be supplied blended groundwater. Link to detailed map.
Variations in elevation throughout San Francisco will determine who gets the new blended water. This map shows which streets will be supplied blended groundwater.
The SFPUC’s is tapping local groundwater as a safety measure against disasters that may disrupt water supply from Hetch Hetchy Regional Water System. Forty-Five new, local wells will draw water from the Westside Basin located in an area under Golden Gate Park that extends southward to Burlingame in San Mateo County. The Westside Basin has supplied drinking water to Daly City, San Bruno, and South San Francisco for over 60 years. The groundwater has been monitored for the past 10 years and will provide drinking water that meets or exceeds all regulatory safety and quality standards set by the California State Water Resources Control Board, Division of Drinking Water, and the U.S. EPA.
Ground Water Testing shows that currently, only 1 mgd (million gallons per day) of groundwater has been added to San Francisco’s 60 mgd average water use. By 2020, a max of 4 mgd will be pumped from the aquifer – 7% the city’s total supply. At the SFPUC’s public meeting in June, General Manager Harlan Kelly, responded to concerns about the taste of new water blend, stating that the low introductory level is not enough to affect the taste of the water. Longtime commissioner Ann Moller Caen, raised the issue of increased nitrate content and questioned why groundwater is being added this year when record rains raise water levels to the top of the dam at Hetch Hetchy.
The SFPUC sure has its work cut out for them if they are still trying to get their own commissioner onboard with the plan. More information and monitoring results will be available when all the wells come online by the end of the summer. Stay tuned for update, and have your tap water tested if you have any concerns.
Many folks interested high fidelity sound systems or low-EMF environments want to minimize electromagnetic interference (AKA: EMI, High-Voltage Transients, Electrical Noise, and Dirty Electricity) from lighting systems. Compact fluorescent lightbulbs (CFLs) – the curly pig tail variety with some mercury in them – are notoriously “dirty” and create significant EMI. As the lighting industry and energy code gravitate toward Light Emitting Diodes (LEDs), more and more are curious about dirty electricity from LEDs.
LED Dirty Electricity Pie Chart for One Bulb
Method for Testing Dirty Electricity from LEDs
While there are many methods for testing dirty electricity, this is how we embarked on this quick comparison study of several bulbs with satisfactory other lighting characteristics.
Magnetic Field (MF) and Electric Field (EF) strength were measured with a Gigahertz Solutions NFA 1000 Low Frequency EMF Meter. MF and EF measurements were recorded at distances of 1 inch, 3 inches, 6 inches, and 12 inches from each bulb. To provide consistency, lamp and extension cord positions were not moved during or between sampling events for each lightbulb. Graphs and tables of collected data are displayed below. CREE, Tala, FEIT Electric, USHIO Utopia 2, Sylvania, and Sunlite A19 bulbs were tested, as well as GE Helical and GE Reveal compact fluorescent bulbs (CFL) and an incandescent bulb from an unknown brand. EF and MF levels were also measured with no bulb attached for ambient concentrations.
Charts Comparing EMI from Various LED Bulbs
Dirty Electricity from LEDs – Magnetic Fields
Dirty Electricity from LEDs – Electric Fields
Dirty Electricity From LEDs Bandwidth Comparison Chart
Results from Dirty Electricity Testing of LEDs
The highest Dirty Electricity from LEDs MF levels were observed with the CREE and GE Helical bulbs. These bulbs measured above 20 milligauss (mG) at a 1 inch distance, while all other bulbs measured below 4 mG at the same distance. The Tala and Sunlite A19 bulb measurements were similar to ambient levels.
The highest EF levels were observed with the CREE, Sunlite A19, and incandescent bulbs. All bulbs were measured at higher than observed at ambient concentrations.
The CREE, Tala, and FEIT Electric bulbs measured the highest in dirty electricity.
The 50/60 Hertz electricity bandwidth range of the Tala, Sunlite A19, and incandescent bulbs contributed to over 97% of the total electric field; The 50/60 Hertz range of the Sylvania, USHIO Utopia 2, FEIT Electric, and CREE bulbs contributed to over 85% of the total electric field; The 50/60 Hertz range of the GE Helical and GE Reveal CFL Bulbs contributed to 59% and 71% respectively of the total electric field.
We thank Clear Light Ventures for funding this study and supporting education about dirty electricity and impacts to human health and wellbeing.