Monday, January 31, 2011

In the EPA’s TMDL Pollution Diet The Biggest Looser is Northern Virginia

The most recent meeting of the Potomac Watershed Roundtable was in Warrenton, VA at Lord Fairfax Community College and had a series of speakers on the Chesapeake Bay strict pollution diet, the Total Maximum Daily Load (TMDL) mandated by the EPA to the six Chesapeake Bay Watershed states and the District of the Columbia. The TMDLs were assigned by the EPA to each segment of the Chesapeake Bay Watershed. For the TMDL, the Chesapeake Bay’s tidal waters have been divided into 92 tidal water segments. There are 35 segments controlled by Virginia and another five Maryland owned segments that include Virginia drainage areas. The different water segments are determined by their varying degrees of salinity, recalling that the Chesapeake Bay Watershed is an estuary. Finally, the TMDLs address only pollution from excess nitrogen, phosphorus and sediment. No action has been taken on other pollutants that might be present in the Chesapeake Bay and its tributaries.

On November 29th 2010 Virginia, submitted the final version of the Virginia Chesapeake Bay Watershed Implementation Plan (WIP) to the U.S. Environmental Protection Agency and December 29th the EPA accepted the revised version of Virginia’s WIP and issued the “final” TMDL, but with “enhanced oversight.” (Doesn’t that sound like fun.) The TMDLs were created by a series of models of the Chesapeake Bay Watershed that include various land use models, water quality models and watershed models. These computer models are mathematical representations of the real world that estimate environmental events and conditions. The models are at best imperfect, but they are nonetheless the best tool available to view the 64,000 square miles of the watershed. The Chesapeake Bay and its watershed are so large and complex, that scientists and regulators rely on computer models for critical information about the ecosystem’s characteristics and the impact of various environmental actions to reduce pollution. It is possible that they have been spending a wee bit too much time looking at computer output and missed the big picture.

Mike Rolband, President of Wetland Studies and Solutions, Inc. had an interesting presentation pointing out poor model behavior, mistakes and injustices of the current TMDL, what EPA has called the strict pollution diet, but really is an excess nutrient diet. When Mike showed the group his slides, several aspects of the Chesapeake Bay Watershed, the EPA’s models, the mandated TMDLs became very clear for me. First of all, the level of excess nutrients in each of the major tributaries to the Chesapeake Bay is fairly well known and well predicted and calibrated by the models. Second, this is indeed a diet, the Chesapeake Bay is overwhelmed with excess nutrients and sediment, and like an obese person, less nutrients will improve the situation. Thirdly, land use and population density matter, but generally the higher the population the more total nutrients are released. Waste water treatment plants and urban runoff and septic contribute a larger load of nitrogen than the agricultural sector. Finally, the EPA mandated TMDL and the approved WIPs to implement them require a percentage reduction in nutrient load from each sector.

This turns out to be vastly inequitable. Eliminating the agricultural sector, Northern Virginia with 46% of the watershed population is required to obtain a total nitrogen load for the waste water treatment plants, urban and septic of 2.52 pounds of nitrogen/person/year while the James River Basin is only required to obtain 6.38 pounds of nitrogen/person/year and the state target average is 4.43 pounds of nitrogen/person/year. This is the equivalent of mandating a diet for everyone in Virginia to lose 1/3 of their body weight. This might be just fine and actually beneficial for the 300 pound people who will be forced to lose 100 pounds, but it is lethal for the 150 pound Potomac Watershed that will have to loose 50 pounds each. We in northern Virginia are trapped in some Kafka version of a diet where slow death by starvation (stopping population growth and potentially reducing population) may be the unintended consequences of the EPA mandated pollution diet.

Thursday, January 27, 2011

HB 2492 Proposes an Amendment to Alternative Septic and Homeowner Responsibilities

Timothy D. Hugo, member of the Virginia General Assembly for the 40th District (Centerville) has introduced a bill HB 2492 in the current session of the Virginia General Assembly: “Onsite sewage systems; certain owners may be exempt from requirements for operation and maintenance.”

This bill contains several provisions restricting the scope and applicability of the new Alternative Onsite Sewage System, AOSS, regulations and the recently implemented Emergency AOSS regulations. The bill would exempt AOSSs installed prior to January 1, 2010, with flows of less than 1,000 gallons per day serving a single-family, owner occupied dwelling from the requirements for the operation and maintenance of the system. In addition, the bill would prevent local autonomy in deciding if these systems can be installed and need to be maintained as recommended by the manufacturer, as currently required by the Department of Health in individual counties. By reducing the authority of the Department of Health and counties to require the maintenance of AOSSs this bill threatens drinking wells with contamination from other properties and is entirely counter to the provisions of the Virginia Watershed Implementation Plan and good stewardship.

Let’s look at how requiring operation and maintenance might protect public health and the environment. A real world example would be a geologically unfavorable groundwater rich location. The small development where I live is located within the northeast quadrant of the Culpeper basin in Prince William County. Groundwater flows under ambient pressure from Bull Run Mountain towards Bull Run, the river flowing west to east. The soils in our neighborhood 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.) In the siltstone bedding plane, the fractures within the rock run predominately north south. Thus while ground water flows generally speaking west to east, water or a contaminant that catches a fracture will carry the contaminant to drinking water depth in a north south pattern. Contaminants can enter the groundwater at these fractures and zigzag through the neighborhood. There is no natural attenuation in a fractured system. Any malfunctioning septic system, improper disposal, or spill on any property has the potential to impact the drinking water well of other residents to the south, southeast or east.

The alternative septic regulations require me and all my neighbors to properly operate and maintain our AOSSs. This will hopefully prevent the neighbor’s septic system from contaminating the drinking water wells in the neighborhood. (I already have an operation and maintenance contract and my septic alarms to an automatic dialer to the maintenance company and my e-mail.) A cracked septic tank, malfunctioning system, improper management of stables, dumping of chemicals down the drain or in the yard, all have the potential to impact large sections of the neighborhood and need to be diligently guarded against by all residents to protect or drinking water supply. Unfortunately, many homeowners are unaware of how septic systems work and what is necessary to maintain them. Their wish to be exempted from the septic regulations is so that they can ignore problems instead of taking appropriate responsibility for their systems without some sort regulations and enforcement. The proper operation and maintenance AOSS would serve to ensure the proper operation of these AOSSs and serve to protect neighboring properties and drinking water supplies from contamination.

The need to negotiate the best rates for AOSS contracts may offer the opportunity for the home owners to create a buying group and educate their neighbors. This could serve to protect all our drinking water. That remains to be seen; in the meantime I will be testing my water twice a year.

Monday, January 24, 2011

The Error in the Allocation to Agriculture Under the Virginia TMDL

The most recent meeting of the Potomac Watershed Roundtable was in Warrenton, VA at Lord Fairfax Community College and had a series of speakers on the Chesapeake Bay strict pollution diet, the Total Maximum Daily Load (TMDL) mandated by the EPA to the six Chesapeake Bay Watershed states and the District of the Columbia. The TMDL addresses only pollution from excess nitrogen, phosphorus and sediment. No action has been taken or at this time is intended on other pollutants that might be present in the Chesapeake Bay and its tributaries. Part of the meeting was devoted to educating the audience on the Chesapeake Bay Model.

The TMDLs were created by a series of models of the Chesapeake Bay Watershed that include various land use models, water quality models and watershed models. These computer models are mathematical representations of the real world that estimate environmental events and conditions. The models are at best imperfect, but they are nonetheless the best tool available to view the 64,000 square miles of the watershed. The Chesapeake Bay and its watershed are so large and complex, that scientists and regulators rely on computer models for critical information about the ecosystem’s characteristics and the impact of various environmental actions to reduce pollution.

Mike Rolband of Wetland Studies and Solutions, Inc. had some fun with what is apparently one of the large mistakes in the model that is expected to have a correction released in the near future. His professional interest is in managing impervious and pervious surface run off. His consulting firm looked at the underlying data used to create the Land Use estimates. Land Use model estimates the types and amounts of pollution that run off a particular land use are based on comprehensive reviews of the latest scientific literature there is limited measurement here for many of the land uses, but the responsible land use is assigned a numeric blame. Using EPA published data Wetland Studies and Solutions was participant in pointing out to the EPA that they had massively underestimated the impervious and pervious surface areas in the Urban Areas in Virginia (and I assume other areas).

It seems that the most recent version of the model had used approximately 675,917 acres for the impervious surface data and 1,885,915 acres for the pervious surface data. A review of the EPA’s own data found that there were 1,569,377 impervious acres and 3,442,346 pervious acres in the urban areas in the Virginia segments of the model. These include all the paved and landscaped areas of suburbia. Between the 1990 census and the 2010 census the population of Virginia grew from 6.2 million people to 8.0 million people. The bulk of that growth took place in the urban and suburban centers of the Chesapeake Bay watershed.

Now here is where it gets interesting. Pollutions loads for nitrogen, phosphorus and sediment in the urban areas are calculated using a constant pounds/acre/year for impervious acres as a fixed input, and the pervious load is based on total fertilizer sales data. The bottom line is that the EPA has confirmed that they will not change the loading rate because they have high confidence in the loading rate for the impervious surfaces and the total fertilizer sales are reported and tracked data and is a hard number. Thus the total current oad for the urban areas will increase by 2,238,449 pounds of nitrogen per year, 636,097 pounds of phosphorus/year and 137,680 pounds of sediment/per year. However, the total watershed loads for the overall model will remain the same. So, while the urban area loads will increase, other area(s) loads will have to decrease.

Mike Rolband has pointed out that the agricultural sector will probably have their load reduced. The waste water treatment plants numbers are based on constant sampling necessary for their permits so their overall total contaminant load will not change. The forest lands number is also believed to be a “good” number, so that leaves the agricultural sector and in the case of total nitrogen, also septic. Over 2.2 million pounds a year is a lot of nitrogen it represents of the total load attributed to agriculture. The farm segment has been protesting loudly that they are not being given proper credit for implementation of best management practices and that surface waters are already degraded when they reach their farms.

It seems that the American Farm Bureau Federation who have recently filed suit against the EPA claiming the models are flawed is right. The smug assumption that farmers are the bad guys by the new generation of environmentalists is to an extent wrong. Man is the animal contributing the most nitrogen to the Chesapeake Bay in the form of wastewater treatment plant permitted waste, septic and urban/ suburban runoff. The Chesapeake Bay Foundation owes the American Farm Bureau Federation an apology for their recent quote in the Washington Post.

Thursday, January 20, 2011

Custom Designed Alternative Septic and Department of Health Oversight

Mark D. Obenshain, Virginia State Senator for the 26th District has introduced a bill Senate Bill #1277 in the current session of the Virginia General Assembly: “Professional engineering of onsite treatment works; Department of Health oversight.”

This bill contains several provisions restricting the Department of Health's oversight of the requirements for and the review of onsite sewage systems custom designed by professional engineers. The Virginia Onsite Wastewater Recycling Association, VOWRA, is opposed to the passage of this bill. Some VOWRA members feel it is an attempt to circumvent the regulations on horizontal setbacks and performance requirements for alternative onsite sewage systems, AOSSs. These physical separations are the last defense of my well and my property from a poorly designed and maintained alternative onsite sewage system on a neighbor’s property. By reducing the authority of the Department of Health to maintain these separations this bill threatens drinking wells with contamination from other properties and is entirely counter to the provisions of the Virginia Watershed Implementation Plan and good stewardship.

Septic is a non-consumptive use of water, the water is returned to the earth. It is important that the septic system or AOSS is designed and operated in a way that protects the environment. Whatever goes down the toilet or the drain goes into the earth. Research performed over a decade ago in Dutchess County, NY and North Carolina demonstrated that minimum lot size, vertical and horizontal separations were the controlling factors to maintaining water quality. Adequate dilution, soil filtration and time are necessary to ensure sustainable water quality. Maintaining the horizontal and vertical separation of all septic and AOSS systems is the last protection of the drinking water supply from septic contamination and allows for weather and use irregularities in operation of septic systems and AOSSs.

In recent sessions the General Assembly has passed several bills amending septic requirements. HB 2551/SB 1486 provided that: AOSS designs submitted by professional engineers to the Virginia Department of Health are required to ensure that the treatment works will meet or exceed the standard discharge, effluent, and surface and ground water quality standards for standard commercial systems tested and demonstrated by the industry and permitted in Virginia under Health Department regulations.

My libertarian streak would love to believe that homeowners would care for their septic systems appropriately to avoid the system backing up in the future, contamination of the groundwater (which may be the source of the local drinking water), and future septic system repair bills of tens of thousands of dollars to remediate and replace a system. Unfortunately, many homeowners are unaware of how septic systems works and what is necessary to maintain them. In addition, people do not seem to be able take appropriate responsibility for their systems without some sort of enforcement or the regulations and the current regulations have no penalties or consequences and so far the public seems unaware of them. Thus, the last defense of neighboring properties and drinking water supplies are the horizontal and vertical setbacks.

Monday, January 17, 2011

The Chesapeake Bay Model

The most recent meeting of the Potomac Watershed Roundtable was in Warrenton, VA at Lord Fairfax Community College and had a series of speakers on the Chesapeake Bay strict pollution diet, the Total Maximum Daily Load (TMDL) mandated by the EPA to the six Chesapeake Bay Watershed states and the District of the Columbia. The TMDL addresses only pollution from excess nitrogen, phosphorus and sediment. No action has been taken or at this time is intended on other pollutants that might be present in the Chesapeake Bay and its tributaries. Two of the speakers, walked the Roundtable audience through some of the issues and uncertainties will impact implementing a plan to achieve the TMDLs on the local level.

Clifton Bell of Malcolm Pirnie, Inc. and Mike Rolband of Wetland Studies and Solutions, Inc. walked the group through some of the issues with the EPA “final” TMDL loading levels and how they were obtained. The TMDLs were created by a series of models of the Chesapeake Bay Watershed that include various land use models, water quality models and watershed models. These computer models are mathematical representations of the real world that estimate environmental events and conditions. The models are at best imperfect, but they are nonetheless the best tool available to view the 64,000 square miles of the watershed. The Chesapeake Bay and its watershed are so large and complex, that scientists and regulators rely on computer models for critical information about the ecosystem’s characteristics and the impact of various environmental actions to reduce pollution. Mr. Bell lifted the curtain to point out some aspects of the models.

Although model simulations are an important part of the Chesapeake Bay regulatory mandate, they are not considered by the EPA to be perfect forecasts. Rather, model simulations are the current best estimates. The Chesapeake Bay Model is really made up of several models that are added together to create the whole: the Watershed Model, the Estuary Model, the Scenario Builder, the Airshed Model, the Land Change Model and the Land Use Models.

The Watershed Model incorporates information about land use, fertilizer applications, wastewater plant discharges, septic systems, air pollution, farm animal populations, weather and other variables to estimate the amount of nutrients and sediment reaching the Chesapeake Bay and which of the major land uses produce these pollutants. This is the most robust and calibrated portion of the model sequence because it is calibrated and validated on the major tributary basin levels where there is decades of measured water quality data available. The Watershed Model divides the 64,000-square-mile Chesapeake Bay watershed into more than 2,000 segments.

The Estuary Model examines the effects that pollution loads generated by the Watershed Model have on water quality. In the Estuary Model, the Chesapeake Bay is further divided into more than 57,000 computational cells and is built on two sub-models: The hydrodynamic sub-model and the water quality sub-model. The water quality sub-model is well calibrated for dissolved oxygen.. However, it is unclear that dividing up the world in ever smaller pieces gives you better resolution when there are not enough hard data points in the cells. Zooming in on a picture without adequate pixels does not increase the resolution.

The Scenario Builder can generate simulations of the past, present or future state of the Chesapeake Bay watershed to explore potential impacts of regulation and management actions and evaluate alternatives. This model creates the assumptions in the regulated community much like Sims game.

The Airshed Model uses information about nitrogen emissions from power plants, vehicles and other sources to estimate the amount of and location where these pollutants are deposited on the Chesapeake Bay and its watershed using information from vehicle registrations and DOT and weather.

The Land Change Model analyzes and forecasts the effects of urban land use and population on sewer and septic systems in the Chesapeake Bay watershed based on: population trends and forecasts, migration, satellite imagery, and waste water treatment plant service area and data. Finally, the Land Use model estimates the types and amounts of pollution that run off a particular land use are based on comprehensive reviews of the latest scientific literature.

Since most of the models were built and calibrated on the data that has been collected over the years they are well calibrated on the major tributaries and basins where most of the sampling and research has been done. The models are designed conservatively; all waste water treatment plants are assumed to discharge their maximum load simultaneously. The best management practices, BMPs, used to manage stormwater and runoff are assumed to be effective only at the low end of their effectiveness range.

In addition, according to Mr. Bell, the model was never designed to be accurate on the local level and this was confirmed in 2008 when the Scientific and Technical Advisory Committee, STAC, Peer Review recommended that the model not be used for local TMDLs. Nonetheless, that is exactly what the EPA did. The models reportedly produce some non-intuitive trends, poorly calibrated results and poor model behavior raising the question of whether the regulatory scheme relies too heavily on the model and will distort desired behavior. They have created a situation where base assumptions are based on the model’s presentation of reality and management practices are not selected for the cost and measured improvement on water quality or ease to maintain, but rather the impact these steps have on model results.

Thursday, January 13, 2011

Potomac Watershed Roundtable Meeting:The Chesapeake Bay, the Virginia Watershed Implementation Plan, and the EPA mandated TMDL

The most recent meeting of the Potomac Watershed Roundtable was in Warrenton, VA at Lord Fairfax Community College and had a series of speakers on the Chesapeake Bay strict pollution diet, the Total Maximum Daily Load (TMDL) mandated by the EPA to the six Chesapeake Bay Watershed states and the District of the Columbia. The TMDL addresses only pollution from excess nitrogen, phosphorus and sediment. No action has been taken on other pollutants that might be present in the Chesapeake Bay and its tributaries.

On November 29th 2010 Virginia, submitted the final version of the Virginia Chesapeake Bay Watershed Implementation Plan (WIP) to the U.S. Environmental Protection Agency. The introduction to the revised plan states that full implementation of the plan would cost more than $7 billion dollars the WIP went on to state that “In these austere times, we cannot guarantee what additional funding will be provided by our General Assembly. It is our position that the success of the WIP may be subject to the provision of sufficient federal funding to assist in covering these massive new unfunded mandates.”

If you recall the first version of the Virginia WIP the plan did not meet the TMDL loading levels with “reasonable assurance.” On December 29th the EPA accepted the revised version of Virginia’s WIP and issued the “final” TMDL, but Virginia will have enhanced oversight. The January 7th 2011 meeting of the Potomac Roundtable addressed the next steps for the counties and towns in the Potomac Watershed. Russ Baxter, from the Virginia Department of Environment Quality, DEQ, closed the meeting with the State’s perspective and issues facing the state and local governments in implementing the WIP. I found Mr. Baxter’s perspective to be very enlightening and so I share some of his points.

Mr. Baxter was emphatic that the WIP is a living document intended to attain the TMDL and contains proposed management action among the sectors of the Chesapeake Bay Watershed that are the source of nutrient contamination to the Bay. The WIP is designed not only to satisfy the demands of the Federal regulators but to allow flexibility to the local governments in implementation to allow them to use the most cost effective approach to achieve the TMDL goals. Also, Mr. Baxter acknowledged that the septic portion of the WIP read like a limitation on developing new housing in the region, but that was not intended to happen.

When the Chesapeake Bay Model is revised to correct know deficiencies in the near future the TMDLs mandated to Virginia and the other states and DC will be revised and the Phase II of the WIP will have to be developed to reflect these changes. Though, the Phase II WIPs are supposed to be due in 2011, EPA has yet to notify the states and DC of the changes and in reality it is unlikely that the changes will be available before the annual Virginia Legislative session. Mr. Baxter pointed out that the WIP is intended to achieve the current 2017 check points with “reasonable assurances” and achieve a restored Bay by 2025. We know what direction we are heading in and can start this leg of the journey, making course corrections as we go.

The Potomac Watershed Roundtable was founded in 2000 and serves as a regional government-citizen forum to collaborate and cooperate on environmental issues among the various local government and stakeholder groups of nine counties, six towns and cities, the six soil and water conservation districts and various stakeholders including interested citizens.

Monday, January 10, 2011

Potomac Watershed Roundtable Meeting: The Virginia Watershed Implementation Plan, and septic regulation in Virginia

The most recent meeting of the Potomac Watershed Roundtable was in Warrenton, VA at Lord Fairfax Community College on January 7th 2011. The session addressed the Chesapeake Bay strict pollution diet, the Total Maximum Daily Load (TMDL) mandated by the EPA and the Virginia Chesapeake Bay Watershed Implementation Plan (WIP) to achieve the mandated reduction in nitrogen, phosphorus and sediment pollution.

The revised WIP also reduces the rate of growth in on-site sewage disposal systems, or septic. The stated intension is to raise the costs to operate a septic system through regulation which would make clustered systems or community systems more competitive and raise the overall cost of building and maintaining homes. The cost of constructing housing would increase in the area in response to these requirements. Though according to the Department of Environmental Quality, DEQ, it is not intended to limit regional growth, the requirements cannot help but impact housing costs and availability.

In addition the revised WIP proposes to require the offset new system loads through an expansion of the Nutrient Credit Exchange Program. The Commonwealth intends to implement amendments to Virginia Department of Health regulations for alternative systems which are currently a bit in limbo because of the temporary emergency regulations that the department of health has done little to enforce in much of the Commonwealth and are set to expire on April 7th 2011, but can be extended for 6 months.

The proposed amendments to the current Emergency Regulations that require all single family alternative onsite sewage systems, AOSS, continue to have professional operators certified by DPOR to operate and maintain the AOSS in accordance with the operating permit, and visited by the operator as specified in the operation permit (typically once or twice a year for preapproved commercial systems) and finally an annual maintenance report submitted to the regulators by the operator. In addition, sampling at startup to confirm proper functioning of the system and every five years for those systems put into operation after the date of the enabling legislation and not grandfathered, like mine.

In addition to those requirements the new legislation requires a minimum 50% reduction in delivered nitrogen for all new small alternative onsite systems in the Chesapeake Bay watershed resulting in an effective delivered load to the edge of the project boundary of 4.5 lbs TN/person/year. Single family home AOSSs are about to get very expensive in the Cheseapeake Bay Watershed if the regulations are enforced.

As Bob Marshall pointed out a few days ago, the civil penalty regulation establishing a uniform schedule penalties for violations of onsite sewage and alternative discharging sewage treatment system regulations. was withdrawn. There will be little or no enforcement. Those who ignore the law will not suffer any consequences. There seems to be very little follow through on the part of the VDH to even inform the public of the regulations.

The Potomac Watershed Roundtable of nine counties, six towns and cities, the six soil and water conservation districts and various stakeholders including interested citizens was at a loss of how to incorporate these requirements into their programs. If these regulations are necessary and appropriate, then they should not be voluntary. The public should be informed and simple and reasonable penalties established. The public comment period on these changes closes on February 4th 2011. There will be a public hearing on January 25th 2011 at 10 AM at the James Madison Building at 109 Governor Street in Richmond, VA.

Thursday, January 6, 2011

Iron and Manganese in Well Water

Many of the perceived problems with well water are caused by the presence of iron and manganese. Iron and manganese can give water an unpleasant taste, odor and color. Iron causes reddish-brown stain on laundry, porcelain, dishes, utensils, glassware, sinks, fixtures and concrete. Manganese causes brownish-black stains on the same items. Detergents do not remove these stains. Chlorine bleach and sodium carbonate may even make the staining worse. Iron and manganese deposits build up in pipelines, pressure tanks, water heater and water softening equipment. These deposits restrict the flow of water and reduce water pressure. More energy is required to pump water through clogged pipes and heat water if the hot water tank’s heating rods are coated with minerals deposits. In addition, water contaminated with iron and manganese often contains iron or manganese bacteria which feed on the minerals. These bacteria do not cause health problems, but can form a reddish brown or brownish black slime in toilet tanks and clog filters.

Iron and manganese are naturally occurring elements commonly found in groundwater in many parts of the country. Interestingly enough, few surface water sources have high levels of these metals. At t levels naturally present in groundwater iron and manganese do not present a health hazard. However, their presence in well water can cause unpleasant taste, staining and accumulation of mineral solids that can clog water treatment equipment and plumbing. In addition, a persistent bacteria/ biofouling problem may be caused by iron bacteria. Under guidelines for public water supplies set by the Environmental Protection Agency (EPA), iron and manganese are considered secondary contaminants. Secondary standards apply to substances in water that cause offensive taste, odor, color, corrosion, foaming, or staining but have no direct impact on health. The standard Secondary Maximum Contaminant Level (SMCL) for iron is 0.3 milligrams per liter (mg/L or ppm) and 0.05 mg/L for manganese. This level of iron and manganese are easily detected by taste, smell or appearance.

Iron and manganese exist in many different chemical forms. The presence of a given form of iron or manganese in geologic materials or water depends on many different environmental factors. Dissolved iron and manganese are easily oxidized to a solid form by mixing with air. In surface water, iron and manganese are most likely to be trapped within suspended organic matter particles. Groundwater tends to be an oxygen poor environment; typically, the deeper the aquifer the less dissolved oxygen is present. Iron and manganese carbonates in an oxygen poor environment are relatively soluble and can cause high levels of dissolved iron and manganese to be carried from a deep well. If sulfur is present in the water then the iron will form iron sulfide rather than iron carbonate and the water may have the familiar unpleasant rotten egg smell. Sometimes oxygen poor conditions can also occur in relatively shallow wells that have stagnant water with very slow turnover. When the iron and manganese are oxidized reddish brown or black particles form and settle out as water stands. These particles are often found trapped in washing machine filters, water treatment equipment, in plumbing fixtures and on clothing, dishes and utensils.

As mentioned above some types of bacteria react with soluble forms of iron and manganese and form persistent bacterial contamination in a water system (especially one with any type of filter or treatment system to capture these iron or manganese bacteria). These organisms are usually found in waters that have high levels of iron and manganese in solution. The reaction changes the iron and manganese from a soluble form into a less soluble form, thus causing precipitation and accumulation of black or reddish brown gelatinous material (slime). Masses of mucous, iron, and/or manganese can clog plumbing and water treatment equipment. They also slough off in globs that become iron or manganese stains on laundry. Bacterial reactions with iron and manganese do not cause any additional precipitation compared to normal exposure to oxygen. However, precipitation caused by bacteria occurs faster and the slime tends to concentrate staining making it more annoying.

All systems of removing iron and manganese essentially involve oxidation of the soluble form or killing and removal of the iron bacteria.  When the total combined iron and manganese concentration is less than 15 mg/l, an oxidizing filter (natural manganese greensand, manufactured silica gel zeolite coated with manganese dioxide, plastic resin beads, or birm, is recommended. Some filters are coated with a manganese oxide and are regenerated by using a potassium permanganate solution. An oxidizing filter supplies oxygen to convert ferrous iron into a solid form which can be filtered out of the water. Synthetic zeolite is a water softener and while it requires fewer backwashes, it can impact the taste of the water, thought anything might be better than the iron and manganese impacts.

Higher concentrations of iron and manganese can be treated with an aeration and filtration system. This system is not effective on water with iron/ manganese bacteria, but is very effective soluble iron and manganese. In this system an aspirator valve pulls air into the water stream to oxidize the iron and manganese to the carbonate form. The air saturated water then enters a precipitator vessel to allow the iron and manganese time to precipitate out and then is passed through a filter. Backwashing the filter is very important to maintain the filter’s function. This system of removal does not involve any chemical additives.

Chemical oxidation can be used to remove high levels of dissolved or oxidized iron and manganese as well as treat the presence of iron/manganese bacteria. The system consists of a small pump that puts an oxidizing agent into the water before the pressure tank. The water will need about 20 minutes for oxidation to take place so treating before a holding tank or pressure tank is a must. After the solid particles have formed the water is filtered often through a sand filter with aluminum sulfate added to improve filtration. The oxidizing agent is used is chlorine, potassium permanganate or hydrogen peroxide. If chlorine is used, an activated carbon filter is often used to finish the water and remove the chlorine taste. Chlorine oxidation requires a pH of 7 +/_ 0.5. Potassium permanganate is more effective on water with a pH above 7.5, but is poisonous and a skin irritant and requires very careful calibration, maintenance and monitoring. Hydrogen peroxide is less pH sensitive.

Careful monitoring and maintenance of a water treatment is necessary to maintain a high quality of treated water. Testing and maintaining your water supply and treatment system is your responsibility. Without regular monitoring, maintenance and adjustments your results are likely to be disappointing.

Monday, January 3, 2011

Hard Water and Water Softeners

In many parts of the country (including mine) the water contains high levels of dissolved minerals and is commonly referred to as hard. Groundwater very slowly wears away at the rocks and minerals picking up small amounts of calcium and magnesium ions. Before considering treating your water test it to get a full picture of the nature of your water supply. No treatment is without consequences and an inappropriate treatment could create other problems. In addition, the characteristics of the groundwater may change over time. The WaterCheck with Pesticides is an informational test packages targeted to be an affordable option for consumers, thought it costs over $200. The WaterCheck with Pesticide covers 15 heavy metals, 5 inorganic chemicals, 5 physical factors, 4 trihalo methanes, 43 volatile organic chemicals (solvents), and 20 pesticides, herbicides and PCB’s. This relatively “affordable” test will serve as a broad screen of your drinking water and guidance as to what (if any) treatment you might want. After testing my water and considering all the options I determined the best option for me was not to treat.

Water containing approximately 125 milligrams of calcium, magnesium and iron per liter of water can begin to have a noticeable impact and is considered hard. Concentration of magnesium and calcium above 180 milligrams per liter is considered very hard. As the mineral level climbs, bath soap combines with the minerals and forms a pasty scum that accumulates on bathtubs and sinks. You either must use more soap and detergent in washing or use specially formulated hard water soap solutions. These minerals also combine with soap in the laundry, and the residue doesn’t rinse well from fabric, leaving clothes dull. Hard water spots appear on everything that is washed in and around the home from dishes and silverware to the floor tiles and car (though commercial car washes use recycled water and are more environmentally friendly). When heated calcium carbonate and magnesium carbonate are removed from the water and form a scale (lime scale) in cookware, hot water pipes, and water heaters. As the scale builds up more energy is required to heat the water and hot water heater and appliances have work harder which will burn them out eventually. Thus, in hard water locations hot water heaters and other appliances have a shorter life.

There are a number of simple things you can do to reduce the effects of hard water in your home, without having to resort to treating your water, so called softening. My water has elevated levels of calcium and magnesium 170 milligrams per liter yet I do not have a whole house water softener. The simple things to do to address hard water are:
Choose a detergent based laundry product. Some laundry detergents/soaps do not produce as many suds in hard water, these are likely to be soap-based products and do not work as well in hard-water as detergent based products. These days, there are laundering powders and liquids available for a wide range of water hardness. Also, manufacturers often recommend using slightly more detergent to compensate for the hard water. Check the package. Occasionally running your washing machine with vinegar and hot water will clear out the buildup of lime scale.

Reduce the temperature of your hot water heater. When water temperature increases, more mineral deposits will appear in your dishwasher, hot water tank and pipes. By reducing the temperature, you will save money and will reduce the amount of mineral build-up in your pipes and tank. Use rinse agents to remove mineral deposits. There are low pH (acidic) products available to remove mineral deposits from pots and pans and dishwasher. Alternatively, you can use plain white vinegar by using the dishwasher dispenser or placing a cup of vinegar on the dishwasher rack. Boil some white vinegar in your kettle to remove hard water deposits. Drain and rinse your hot water heater annually.

In days past, at the first sign of hard water, domestic water supplies were commonly softened by using a commercial water softening system. Water softening is basically an ion exchange system. The water softening system consists of a mineral tank and a brine tank. The water supply pipe is connected to the mineral tank so that water coming into the house must pass through the tank before it can be used. The mineral tank holds small beads of resin that have a negative electrical charge. The calcium and magnesium ions are positively charged and are attracted to the negatively charged beads. This attraction makes the minerals stick to the beads as the hard water passes through the mineral tank. Sodium is often used to charge the resin beads. As the water is softened, the sodium ions are replaced and small quantities of sodium are released into the softened water, thus the taste.

Eventually the surfaces of the beads in the mineral tank become coated with the calcium and magnesium. To clean the beads, a strong salt solution held in the brine tank is flushed through the mineral tank. Sodium is typically use, but potassium can also be used. The salt ions also have a positive electrical charge, just not quite as strong as that of calcium and magnesium, but the high concentration of salt ions overpowers the calcium and magnesium ions and drives them off of the beads and into the solution. The excess sodium solution carrying the calcium and magnesium is flushed to the septic system. Some sodium ions remain in the tank attached to the surfaces of the beads and the resin is now regenerated and ready to continue softening the water.

The amount of sodium in water conditioning systems is a real problem for humans and the environment. All of the salt is released into the septic system and ultimately the leach field and groundwater. In addition softened water should not be used to water house plants, the salt build up will eventually kill them and they will not thrive. Softened water should also not be used in steam irons or evaporators like evaporative coolers. In addition, while some studies have shown that sodium does not interfere with bacterial action in ATU tanks in alternative septic systems, David Pask, Senior Engineering Scientist of the National Small Flows Clearinghouse has seen septic distribution pipes plugged with a “noxious fibrous mass” that was grease and cellulose from toilet paper that only occurred in homes with water softening systems. He felt the brine in the conventional septic tank had interfered with the digestion of the cellulose fibers and might be carried over into the septic systems drain field. Field practitioners reported to the Small Flows Clearinghouse negative impact from water softening regeneration brines.

Personally, I do not care to add all that sodium to my diet while removing calcium carbonate and magnesium (something that is also sold in pill form for stronger bones). If you must soften your water there is another option. Potassium chloride can be used instead of sodium chloride. Potassium chloride works exactly the same way that sodium chloride does in the softening process and the potassium chloride reduces the amount of sodium in drinking water, the potassium in the treated water is a necessary mineral and it eliminates the excess sodium in the septic system, drain field and released into the environment. Potassium chloride costs much more than sodium chloride. A forty pound bag of pellets costs $36 for Potassium chloride and under $8 for sodium chloride. One final note, though magnetic water softening is sold, according to research done at Perdue University in the 1990’s this method of water conditioning was not effective.