All posts by NE

The Breakdown of Water Use

As a society, we use water for drinking, washing, agriculture, industry, landscape watering, and carrying wastes. Overall, agriculture uses about two thirds of all the consumptive use water, but this varies quite a lot across the USA and is less in New England. Thermal cooling and power supply are also major uses of water, exceeding agriculture, but are generally non-consumptive (nearly all the water is put back into the system from which it came). Public supply water, used in residential, commercial and some industrial operations, accounts for about 11% of the total consumed; most of that is used for irrigating ornamental landscapes. Inside the house, water is used for drinking and cooking, but much more is used in bathtubs, washing machines, and toilets.

There is certainly variability over geographic areas, but most of the northern USA has a consumptive use of between 70,000 and 110,000 gallons per person per year. Arid southern areas can use as much as 200,000 gallons per person per day, but most of the difference is landscape watering. If a person used 5 gallons per day for drinking, cooking and washing, all uses where having very high water quality is important, that would equate to 1825 gallons per year, less than 2% of total consumptive use.

This raises some interesting questions. Should we be applying the same high level of treatment to meet stringent standards for the vast majority of water used in ways where that treatment is essentially wasted? The answer appears to be yes, but only because it all arrives at our homes in the same distribution system. Should we be pushing so hard for water conservation in the home when it represents such a small portion of water used? A yes answer is more philosophically satisfying than practical. If irrigation is the dominant use, why is so little effort expended on conservation of that use and so much attention paid to minor uses like bottled water? The answer may be that we have less apparent control, but there is technology to improve irrigation efficiency and we could do without some crops at some times of year to avoid all that water use in arid areas.

A truly comprehensive water policy at federal and state levels should demonstrate a clear understanding of how much water is used for what purpose and apply proper technology and restrictions to conserve a valued resource while recognizing economic limits. We should be pursuing multiple distribution systems that can carry water of the appropriate quality for corresponding uses. Landscape watering needs to be cut by a lot, or even eliminated. Irrigation water conservation should be a top priority. We have a long way to go to reach a sound water management position.

Irrigated cropland.


Algaecides are chemicals used to directly kill algae. The Latin root is simple – algae, or microscopic plants, and cide, a killing agent. By far the most common algaecide is copper, in use for over 100 years and very effective against a wide range of algae. There are many formulations, with differences mostly intended to improve effectiveness or duration of activity under various environmental conditions, but the key ingredient remains the copper ion itself. After reactions are complete, the copper remains, and is usually deposited in the sediment. This can’t be good for the lake, but there are few studies that have demonstrated any measurable negative impacts. With repeated treatment, the sediment may be considered hazardous waste if ever dredged, but for the most part the reacted copper appears to be inert. Doses of copper in New England waters rarely exceed 0.2 mg/L as copper, and are often <0.1 mg/L. Larger doses are used in some other parts of the USA, mainly to overcome interference by high suspended or dissolved solids, and these are poor examples to compare with New England applications. Some zooplankton and some trout species may be susceptible to toxic effects at applied doses, but the vast majority of non-target aquatic organisms are not threatened by copper doses used in New England.

A more recent algaecide is peroxide, formed from sodium carbonate peroxyhydrate when added to water. It is an oxidant that impacts cell walls of algae, with groups like cyanobacteria being generally more susceptible than stronger walled forms like some greens and diatoms. It leaves no potentially hazardous residues. The primary drawbacks are that sometimes we want to kill green algae, especially mats of filamentous forms, and peroxide-based algaecides are more expensive than copper alternatives. Still, the generally positive environmental profile of peroxide-based algaecides makes them attractive. Peroxides seem to be more effective than copper on cyanobacteria mats, which are often sources of taste and odor in reservoirs.

There are a few other manufactured algaecides that have specialized applications, but copper and peroxide represent nearly all the market for this type of treatment. It is preferable to limit nutrients to control algae, but this is much easier said than done, and having algaecides as a management option helps make our drinking water safe and our recreational lakes swimmable. Excessive use of algaecides should be avoided, and control of nutrients should be pursued as a long term solution, but algaecide application is a valuable management tool that should not be rejected without careful consideration.

The biggest issue with treatment is the tendency to wait until there is a major accumulation of algae to treat. At that point treatment will lead to a lot of decaying organic matter, release of nutrients, and possibly release of toxins. This latter possibility has led many states to disallow treatment if potentially toxic algae are too abundant. The most effective way to use algaecides is to prevent a bloom, not get rid of one. This means tracking algae on a regular basis, typically weekly, and reacting when problem species start to increase, which is not an easy task.

One other important point about algaecides warrants attention. As noted at the start, these are compounds that directly kill algae. Some regulatory agencies, notably but not exclusively in New York, have defined algaecides as any additive that prevents algae from becoming abundant. Consequently, phosphorus inactivation with aluminum or lanthanum is considered to be algaecide application, and since these are not registered as algaecides with the federal government, treatments using them cannot be permitted. By this line of reasoning, addition of oxygen to the bottom of a lake to keep phosphorus sequestered is also an algaecide application, and addition of water to cause dilution or flushing in a lake would also represent application of an algaecide. This sort of regulatory foolishness hurts sound lake management and highlights why it is institutions that limit success far more than science or economics.

Monitoring Algae

How can one know what algae are in the water? Sometimes the growths are large enough that someone can see enough with the naked eye to make at least a preliminary identification, but for the most part algae identification requires the use of substantial magnification. For many years (literally over 200) we have used lens systems organized into what we call a microscope to magnify algae enough to tell what they are, and there are few substitutes for looking. Even then, considerable training is needed to know what is being observed, leading to bottlenecks in getting algae data to support lake management. Having a trained phycologist (one who studies algae) look at algae under a microscope remains the most preferred option, but some useful substitutes have arisen with digital technology. A digital microscope can magnify an image on a screen for under $1000. That image can be captured as a photo that can be compared with online sources or sent to an expert. The USEPA, Region I, has been pioneering an effort to get lake groups with an interest in harmful algae blooms to use such systems to report algae in their lakes. The accumulation of images can be turned into useful data that allow characterization of bloom frequency, common bloom species, and possibly trends within or among lakes.

The advent of automated systems for detecting and photographing particles makes it possible to process samples quickly, but we are just getting to the point where image libraries can be used by instruments to actually make identifications. The FlowCam, made by Fluid Dynamics in Maine, counts particles and photographs them, allowing the user to catalog and identify them with some expertise. At even a rudimentary level, such systems allow fast assessment of possible threats to lake uses. The Imaging FlowCytobot, developed by Woods Hole MA scientists, has been adapted by PhycoTech of Michigan to actually make identifications, and this technology could meet the need for rapid but taxonomically detailed and accurate data generation. These instruments are expensive, but contracting for identification can be affordable.

While lack of images (visual or digital) limits identification, use of fluorescence systems to determine the amount and types of pigments present can help discern algae blooms. Chlorophyll-a, a photosynthetic pigment common to all algae, can be assessed with fluorescence, which is basically the amount of light at a particular wavelength emitted from a water sample after excitation by light at another wavelength. The amount of chlorophyll-a in different types of algae varies, so this is not a direct measure of biomass, and the quality and amount of natural light and the concentration of non-photosynthetic organic matter in the water can cause variation not related to algal biomass. However, in a general sense, fluorescence can be used to get a rough appraisal of how much algae is in the water. Further, phycobilin sensors that detect pigments specific to cyanobacteria and provide an estimate of how much cyanobacteria are in the sample. There are even more sophisticated systems that excite samples with a range of wavelengths and record fluorescence in a way that allows a relative approximation of multiple algae types in the sample. Calibration and “training” of the instrument for specific waterbodies improves reliability.

Compared to identification and mapping of rooted aquatic plants, algae assessment is more challenging, but effort is needed if one wants to understand all important aspects of a lake.

NECNALMS 2017 Conference

Come join us this Friday and Saturday for our annual 2017 NEC NALMS Conference, New England Waters: Real World Watershed Monitoring and Management Options! This year, our conference will be hosted by URI Watershed Watch, the New England Chapter of North American Lake Management Society, and Save The Lakes, Rhode Island’s Association for Lakes. The conference will take place this Friday, June 9th, and Saturday, June 10th, in Kingston, Rhode Island at the University of Rhode Island’s Center for Biological and Life Sciences. Friday will consist of workshops and the NEC-NALMS meeting, while Saturday will have general sessions and a tour of the EPA Mobile Lab. Both days will have other optional events, such as dinner and a paint and sip! Please help us accomplish our goal of bringing together New England’s citizens, scientists, and professionals to share information and experiences in order to help restore and protect our lakes and watersheds! For more program and cost information, please visit our website or contact We look forward to seeing you there!

Size Matters

The relative size of a watershed vs. the area of the lake it drains into has a large influence on water quality, independent of land use in the watershed. Lakes which are small relative to the area of their watersheds are subject to higher loading of nutrients per unit area and shorter detention times (more rapid flushing). As the watershed gets larger or the lake gets smaller, lake water quality becomes more and more a function of incoming stream water quality. Internal processes may not matter much when the watershed is delivering large amounts of water and associated contaminants such as sediment, bacteria, nitrogen and phosphorus.

On the other hand, a larger lake with a smaller watershed may be minimally affected by its watershed on a day to day or week to week basis, with seasonal influences or even annual influences being the shortest time frame for change identifiable by monitoring. For lakes with detention times of close to a year or more, internal processes may dominate water quality, such as loss of oxygen in deep water and release of phosphorus from affected sediment. The inputs from the watershed matter in the long run, but do not greatly affect daily to monthly conditions when the incoming water is such a small percentage of the lake volume.

There is not an official cutoff for small and large watershed to lake area ratios, but a generally accepted scale has ratios of 50:1 having very high watershed influence on a short term basis. In all cases land use matters, but in the range of ratios of 20-30:1 that influence becomes very important. A watershed that is 20 times the size of the lake it drains into may have limited negative impacts if all forested, while the same ratio for a largely urbanized watershed may greatly impact water quality in the lake after storms.

It is therefore recommended that lake studies include a careful analysis of watershed to lake area ratio and land use within that watershed. Simple but fairly reliable models can be used to predict water quality based on these and a few other easily obtained watershed features, and represent an economical head start to understanding your lake and its management needs. Watershed and land use data can be readily obtained online for most areas, with a host of GIS-based programs available for use by those with minimal cartography skills. Try these out! It is actually fun as well as very educational. Do you know what flows to your lake?

Watershed size and land use mapping is now pretty easy from the comfort of your home.

Eutrophic Drinking Water

Providing safe drinking water is a major industry in the USA, and that industry rises to many challenges. The vast majority of drinking water flowing out of faucets is extremely safe and reliable, despite the occasional catastrophes (Toledo OH and Flint MI receiving the most publicity in recent years). The Safe Drinking Water Act (SDWA) was promulgated and amended several times to legislate what consumers get, and has a lot of beneficial provisions. However, there can be unintended consequences.

For example, the SDWA calls for corrosion prevention measures to minimize leaching of lead and copper from distribution pipes. It would be better to replace those pipes, but it is true that some drinking water is acidic and some leaching could occur from any metal pipe, so adding substances that coat the pipes or minimize leaching makes sense. However, the cost of anti-corrosion additives is not negligible, and it turns out that the most common (read “least expensive”) anti-corrosion agent includes a lot of phosphate. The concentration of phosphorus in water sent to customers for potable consumption can be more than 300 ug/L. That level of phosphorus is not unhealthy for people, but algae blooms can be caused by as little as 20 ug/L.  Algae are not going to bloom in dark distribution pipes, but once that water sees the light of day, growth is possible. Watered lawns may need less fertilizer as a result, but any runoff from such watering could wreak havoc on the receiving stream or lake. Flushing fire hydrants, an occasional operational need, can put a lot of phosphorus in the nearest water body.

We know that drinking water from a lake without treatment may be hazardous to our health, but how many of us know that the water we receive from most public supplies may be hazardous to the lake.

Is your tap water safe for your lake?

Drinking Water in Toilets

Those who remember comic Bob Newhart’s skits probably recall his famous rendition of Sir Walter Raleigh calling back to England on the not yet invented telephone and telling the queen that he had discovered tobacco. He tries to explain how it is used, and really struggles with making it sound attractive. This may have been an inspiration for many anti-tobacco campaigns, and we need a similar skit about how we treat water. Imagine trying to explain to some space traveler from afar that we spend money to protect our water supplies, expend extreme sums to treat water to make it drinkable, then put more of that water into toilets to convey wastes than we actually consume as potable water. It is hard to envision any explanation as being acceptable. Yet that is exactly what we do, despite existing alternatives, some of which are in use in other countries now. We really need some enlightened leadership to move our water management practices onto more sound ground.

The regulations governing the provision of drinking water are fairly extensive and strict. The water supplied to people for consumption is largely quite safe, despite the occasional hiccup like recent examples in Toledo Ohio and Flint Michigan. Those incidents should not be downplayed, but the public discussion should not focus on details, but rather look at the big picture. Source water protection is important, as is proper treatment, but what often gets forgotten is the distribution system. And that distribution system is grossly antiquated in much of the United States. By having just one intake source per dwelling, we have to receive only the best quality water. But if that distribution system has contaminants built into it, as with lead or copper pipes, we have to load the drinking water up with compounds that adjust the pH, coat the pipes and limit leaching of contaminants. Where the water sits for an extended time in the pipe, due to uneven demand, we have to make sure there is enough disinfectant present to keep bacteria from growing. There is a better solution.

If we had a new, smaller, pipe system to supply water for drinking, cooking and washing, the older pipe system could be used to supply less well treated water for toilet use and perhaps irrigation. There would be a cost to the extra infrastructure, but it could solve a lot of problems with current water quality and split water use in a way that would reduce treatment costs overall. Some places outside the USA now have dyed water coming into dwellings in one pipe for use in toilets, while drinking water is brought to taps separately. Recycling would mean less demand, both quantitatively and qualitatively. Utilities struggle to provide enough safe drinking water at times, especially during droughts, and we could ease that burden if we reduced the amount of high quality water that we literally flush down the toilet.

What’s next? Stocking toilets for fishing?

Low Impact Development

Development and property management techniques that minimize water pollution impacts off-site are called Low Impact Development, or LID. There is some very clever engineering involved in some cases, but for the most part this is not rocket science. Sources on the property should be minimized, but recognizing limits on residential properties, the vehicle for off-site transport, runoff, is restricted. The idea is to limit impervious surfaces and collect as much runoff as possible for infiltration or detention on the property. The focus is on actions at the individual property level, rather than some larger downstream facility to hold greater quantities of runoff long enough to allow it to be purified by natural or engineered means.

Typical techniques include bioretention (rain gardens), porous pavement, grass swales, and green roofs. These techniques can work in almost any climate; having a cold winter is not really a deterrent. Sizing is important, but the most critical limitation tends to be soil type. Turning runoff into ground water provides excellent treatment and has not resulted in extensive ground water contamination, although each case must be considered individually. However, not all soils are conducive to receiving as much runoff as can be derived from roofs, driveways and packed lawn areas. Engineering in such cases is most critical and may be challenging. Where runoff cannot be percolated, it may be detained and purified by various means before being released to a stream or lake.

There is a fair amount of literature out there that explains the techniques and reviews results, but one does have to do a lot of reading to get up to speed. One accessible reference that is helpful and has an extensive reference list is Ahiablame, L.M., Engel, B.A. & Chaubey, I. Water Air Soil Pollut (2012) 223: 4253. doi:10.1007/s11270-012-1189-2. Another publication, free from the USEPA, is Reducing Stormwater Costs Through Low Impact Development Strategies and Practices. The key limitation to wider application has been insufficient documentation of results, which is a difficult problem. One can demonstrate success at the individual property level, but showing positive impacts on an entire lake ecosystem is challenging, since the extent of application has to be very high. Another troublesome aspect is that removal of phosphorus, probably the most important nutrient entering our lakes, is not especially high; one cannot completely counter the impact of development on a lake with LID. The good news is that there is very little downside; anything homeowners can do to limit contaminated runoff from leaving the home site will benefit the lake, and application of LID techniques is less expensive than alternative measures.

Reducing Stormwater Costs through Low Impact Development

Being Lake Smart

The best watershed management is applied at the source, but this means getting property owners to actively participate. Watershed management is a challenge, but there are programs to help. One such program is LakeSmart, a program of the Maine Lakes Society (MLS). LakeSmart educates, assists, and recognizes property owners who maintain their home sites in ways that manage storm water and waste water to minimize impacts on lakes. The program was created in 2004 by the Maine Department of Environmental Protection (DEP), expanded in 2009 by a partnership between the Society and DEP, and is now fully privatized under the Maine Lakes Society. The MLS presents its distinctive blue and white signs to homeowners who meet program criteria, and is approaching its 5-year goal of 60 lake association participants by 2018.

LakeSmart awards were presented to over 80 homeowners during the summer of 2015.   Posted at the lakeside and driveway entrances of a property, the distinctive blue and white sign identifies the owner as a person who cares enough to take action to protect the lake. Properties that display the sign show others what lake-friendly living looks like, arouse interest, and motivate similar behavior by other community members. The MLS model for running LakeSmart is cost-effective, leveraging the power, interest and commitment of lake association members to speed the program’s spread.

Many homeowners grew up with suburban landscaping and are accustomed to its tidy lawns and open space. But suburban lawns, with big driveways and wide paths, are deadly for our lakes. LakeSmart landscaping provides a healthy alternative that mimics nature’s rich mosaic of plants, shrubs, winding paths, and shady trees. It looks great, enhances privacy, and works hard to protect property values, wildlife habitat, water quality, recreational opportunities and the vitality of local economies. It looks even better when you understand how important it is to minimize nutrient inputs to lakes. It may be hard to believe that one person’s expansive lawn or eroding camp road could be a threat to something as large and enduring as a lake, but when added to a shoreline full of similar sites, it can have a very real impact, especially over multiple years. All storm water that gets into a lake carries nutrients. Over time, the cumulative impact can be thousands of pounds of pollutants. The result, “death by a thousand cuts,” leads to algae blooms, fish kills, and the loss of water clarity and spawning habitat. One tiny rivulet from one rainstorm may not seem like much, but when multiplied across a lake watershed and added up over decades, eroded soil can turn a lake into a smelly, pea green mess.

This is a program that can be applied anywhere. It is certainly easier to build a lake-friendly property from the start, but retrofitting and minimizing impacts is not really that hard in most cases. Check out the MLS LakeSmart program at and contact Maggie Shannon at the Maine Lakes Society at  for more information.

Where to Get Help

Found an odd plant in your lake? Is the water green when it used to be clear? Not catching as many fish as you used to? Just want to understand what is going on in your lake? These and many more common questions do not necessarily have easy answers. In all likelihood, there is someone around who can in fact answer any lake-related question you can come up with, but finding them can be a chore. Here are a few ideas of where to get help.

In Maine, the Department of Environmental Protection (ME DEP) is home to two groups of lake experts in the Lake Assessment Section and the Invasive Plant Section. The Volunteer Lake Monitoring Program (VLMP) works closely with ME DEP, maintains the Lake of Maine website, and certifies volunteers to collect water quality data and conduct shallow water plant surveys.  Their program website contains a wealth of information, and their staff are very helpful.  Maine also has an umbrella organization that provides assistance to lake associations and individuals across the state, the Maine Lakes Society (MLS). This network of professionals and interested laypeople has their finger on the pulse of proposed legislation pertinent to lakes and keeps members informed; anyone interested in Maine lakes should be a member of this group.

New Hampshire Department of Environmental Services has a solid lakes staff, and the University of New Hampshire also has very talented people who can answer lake questions. Both run volunteer monitoring programs. The New Hampshire Lakes Association is well organized and is celebrating 25 years of service to the lakes community this year; New Hampshire lakes enthusiasts would be well advised to get involved with this group.

Vermont’s Agency of Natural Resources, Department of Environmental Conservation, has an active lakes unit and runs a volunteer monitoring program. The Federation of Vermont Lakes and Ponds is the state lake association and those interested in Vermont lakes should be members. There is also a newly formed statewide organization, the Coalition of Vermont Lakes, which focuses largely on lake restoration.

Massachusetts has a highly fragmented approach to lake assessment and management, so it is difficult to recommend one agency to contact. The Department of Environmental Protection handles permitting on a regional basis, but the Department of Conservation and Recreation has a Lakes and Ponds Program that does more outreach and actual lake management than the DEP. The Department of Fish and Game houses the fishery expertise in Massachusetts, as well as the Natural Heritage and Endangered Species Program, which handles endangered species issues. The Massachusetts Congress of Lake and Pond Associations is the state level organization for lake enthusiasts, and just held a very successful annual conference. If you live in the western part of the commonwealth, the Lake and Pond Association- West is a subset of MA COLAP that you should join.

Connecticut has suffered the greatest losses of lake-related personnel in recent years; there is no identifiable lakes assistance program, but there are knowledgeable people in the Department of Energy and Environmental Protection (DEEP) who can help. Lake water quality monitoring is conducting by the Water Monitoring and Assessment Program at DEEP. The Inland Fisheries Division conducts fish surveys in lakes and large rivers under the Warmwater Fish Monitoring Program. The Agriculture Experiment Station conducts aquatic plant surveys under the Invasive Aquatic Plant Survey Program. There is also a Connecticut Federation of Lakes that offers membership and educational programs to anyone interested in lakes in Connecticut.

Rhode Island has a Department of Environmental Management (RIDEM) that does have personnel who work with lakes, but not a defined lakes program. Save The Lakes (STL), RI’s association of lakes groups, is actively campaigning for a new hire at the department whose focus would be freshwater systems. But until then RIDEM provides STL a list of state contacts for Lakes, ponds and rivers which is available on the STL website. In addition, the University of Rhode Island Watershed Watch, celebrating 30 years of service in 2017 and hosting the NECNALMS conference at URI in early June, has a wealth of knowledge and monitoring data on RI’s lakes. Their website is a central clearinghouse of information for the state and region.

And do not forget about the various consulting firms in New England. While these are for-profit entities, they are for the most part very dedicated to the profession and the welfare of our lakes, and are almost always willing to talk with lake stakeholders about problems and options. Be mindful of how much time you take up, but do not hesitate to contact local firms for advice.

Finally, NECNALMS itself and the international North American Lake Management Society are educational resources with websites and members who can help. These are groups you should strongly consider joining, both for the programs offered and the networking opportunities they present. No one has all the answers, but collectively we can usually figure things out, and both NECNALMS and NALMS represent some of the best minds in the business and the most dedicated lake professionals out there.