Tag Archives: Water supplies

A utility’s novel attempt to force farmers to curb pollution in rivers failed. Now the utility is on the hook for millions of dollars to protect the region’s drinking water.
— Read on


Every water body will be different but in southeast Florida there are a couple options for Lake Okeechobee’s waters.  One option has been in discussion for years – buy back the EAA lands and restore the Everglades flow.  That has two benefits – improved water quality, and less potential for east-west releases.  The downside is cost.  But the sugar industry knows that the muck layer is decreasing and there are plans to develop the EAA into hundreds of thousands of housing units.  That was not the intention in the 1940s when the EAA was created, but trying to stop someone from developing land, especially when the lake communities are challenged economically, is difficult.  Buying the land would remove it from production, but decrease tax revenues.  And it would need to be managed with no guarantee that it would cleaned up quickly.

The alternative?  The South Florida Sun-Sentinel had a front page article that is a little scary.  The figure below is reproduced from that article.  The discussion was if there is no conservation/public purchase of land, Florida may look very different.  The impact of not buying the land is development.  More people.  More taxes.  More stormwater.  The fertilizer does not go away – it now fertilizes lawns and golf courses.  Add wastewater, and human activities.  We find that urban living and farming can have similar impacts from a nutrient perspective.  So development may exacerbate the problem and given that our modeling indicates that sea level rise imperils inland communities from groundwater, this is not a solution to coastal risk.  Given limitations with local governments inland, it may create a larger crisis.  All there things need discussion, but the question is – will the algal issues on the coast improve?

graphic-of-development worse?

The most important parameters regulating algal growth are nutrient quantity and quality, light, pH, turbulence, salinity and temperature. Light is the most limiting factor for algal growth, followed by nitrogen and phosphorus limitations, but other nutrients are required including carbon. Biomass is usually measured by the amount of chlorophyll a in the water column.  Water temperature influences the metabolic and reproductive rates of algae. Most species grow best at a salinity that is slightly lower than that of their native habitat,  The pH range for most cultured algal species is between 7 and 9, with the optimum range being 8.2-8.7. Through photosynthesis, algae produce oxygen in excess of respiratory requirements during daylight hours. Conversely, during low light or nighttime periods algae respire (consume) dissolved oxygen, sometimes depleting water column concentrations. Thus, high algae concentrations may lead to low dissolved oxygen concentrations.

A common solution for algae is copper sulfate.  Copper Sulfate works to kill the algae, but when it dies, it settles to the bottom of the water body where it becomes a carbon source for bacteria and future algae.  One will often see shallow ponds with rising algae.  But there is significant concern about copper in coastal water bodies.  Copper is toxic to marine organisms so USEPA and other regulatory bodies are considering the limits on copper use.  Such a limitation would severely limit options in dealing with algal blooms near coastal waters.

Mixing is necessary to prevent sedimentation of the algae, to ensure that all cells of the population are equally exposed to the light and nutrients.  So oxygenation can help (it also mixes the water.  The depth of south Florida water bodies is problematic (shallow and therefore warmer than normal).  But oxygen will help microorganisms on the bottom consume the carbon source on the bottom, which might slow algal growth.  Analysis is ongoing.

Two other conditions work against controlling blue-green algae outbreaks: climate change and political/regulatory decision-making.  Lake Okeechobee has routine algal blooms from the nutrients introduced from agriculture and runoff around the lake, which encouraged an artificial eutrophication of the lake years ago.  It continues today.  Warmer weather will encourage the algal blooms in the future.  The decisions to discharge the water without treatment is a political one.  From a regulatory perspective, algae is seen as a nuisance issue, not a public health or environmental issue.  But algal blooms consume oxygen and kill fish, so the ecosystem impact is considerable – it is not a nuisance .

The term algae encompass a variety of simple structures, from single-celled phytoplankton floating in the water, to large seaweeds.  Algae can be single-celled, filamentous or plant-like, anchored to the bottom.  Algae are aquatic, plant-like organisms – phytoplankton.  Phytoplankton provides the basis for the whole marine food chain. Phytoplankton need light to photosynthesize so will therefore float near the top of the water, where sunlight reaches it.  Light is the most limiting factor for algal growth, followed by nitrogen and phosphorus limitations), but other nutrients are required including carbon, silica, and other micronutrients. These microscopic organisms are common in coastal areas.  They proliferate through cell division.

A natural progression occurs in many water bodies, from diatoms, to green algae to yellow/brown to blue-green, with time and temperature.  The environment is important.  Southern waters are characterized as being slow moving, and warm.  This encourages cyanobacteria – or blue green algae.  The introduction of nutrients is particularly difficult as it accelerates the formation of the blue green algae. Blue-green algae creates the bright green color, but is actually an end-of-progression organism.

If cells are present in the water mass in large numbers an algal bloom occurs.  An algal bloom is simply a rapid increase in the population of algae in an aquatic system. Blooms may occur in freshwater as well as marine environments. Colors observed are green, bright green, brown, yellowish-brown, or red, although typically only one or a few phytoplankton species are involved and some blooms may be recognized by discoloration of the water resulting from the high density of pigmented cells.

So the desire for development created the idea to drain the swamp, which led to exposure of dark, productive soil that led to farming, which lead to fertilizers, which led to too much water, and water pollution leading to algae.  A nice, predictable progression created by people.  So what is the solution?

How to Predict the next Flint?

IMG_4803In the last blog we talked about Flint’s water quality problem being brought on by a political/financial decision, not a public health decision.  Well, the news get worse.  Flint’s deteriorated water system is a money thing as well – the community has a lot of poverty and high water bills, so they can’t pay for improvements.  They are not alone.  Utilities all over the country have increasing incidents of breaks, and age related problems. So the real question then is who are the at risk utilities?  Who is the next Flint?  It would be an interesting exercise to see if a means could be developed to identify those utilities at risk for future crises, so we can monitor them in more detail as a means to avoid such crises.

So what would be the measures that might identify the future “Flint?”  These could be things like age of the system, materials used, economic activity trends, income, poverty rate, unemployment rate, utility size, reserves, utility rates, history of rate increases, etc.?  Could these be developed into a means to evaluate risk?  If so, who would use it and how would we address the high risk cases?  I suggest that lenders have means to evaluate this using many of these same measures, but from a risk of events, this method has not been applied.  So I think this would be a useful research project.  So if anyone has some ideas, time or ideas for funding, let me know.  Let’s get rolling!

In the last blog I showed what reclaimed wastewater could do for an ecosystem.  Very cool.  But what about for drinking water.  I actually was involved in an indirect potable reuse project several years ago.  The concept was to take wastewater, filter it with sand filters, filter it with microfiltration, reverse osmosis and then hydrogen peroxide and ultraviolet light.  This is what they do in Orange County California when they recharge groundwater, and have been for over 30 years.  Epidemiological studies in the 1990s indicated no increased incidence of disease when that water was withdrawn from the aquifer, and then treated in a drinking water plant before distribution.  So our project was similar – recharge to the Biscayne aquifer in south Florida.   It worked for us.  Total phosphorous was below 10 ppb, TDS was less than 3 mg/L (<1 after RO), and we were able to show 3 log removal of endocrine disruption compounds an d pharmaceuticals.  It worked well.  This is a concept in practice in California.  And will be at some point in south Florida since only the Biscayne aquifer provides sustainable water supplies.  Here is what our system looked like.


sand filters




Reverse osmosis



This is also the same basic concept Big Springs Texas uses for their direct potable program, demonstrating that the technology is present to treat the water.  A means for continuous monitoring is lacking, but Orange County demonstrates that for indirect potable reuse projects, a well operated plant will not risk the public health.  This is how we do it safely.




In the last blog we talked about a side issue: ecosystems, bison, wolves, coyotes and the Everglades, which seem very distant form our day-to-day water jobs, but really are not.  So let’s ask another, even more relevant issue that strikes close to home.  Why is it that it is a good idea to store coal ash, mine tailings, untreated mine waste, garbage, and other materials next to rivers?  We see this over and over again, so someone must think this is brilliant.   It cost Duke Energy $100 million for the 39,000 tons of coal ash and 24 MG of wastewater spilled into the Dan River near Eden NC in 2014. In West Virginia, Patriot Coal spilled 100,000 gallons of coal slurry into Fields Creek in 2014, blackening the creek and impacting thousands of water supply intakes.  Fines to come.  Being a banner year for spills, again in West Virginia, methylcyclohexamethanol was released from a Freedom Industries facility into the Elk River in 2014, contaminating the water supply for 300,000 residents.   Fines to come, lawsuits filed.  But that’s not all.  In 2008, an ash dike ruptured at an 84-acre solid waste containment area, spilling material into the Emory River in Kingston TN at the TVA Kingston Fossil Plant.  And in 2015, in the Animas River in western Colorado, water tainted with heavy metal gushed from the abandoned Gold King mining site pond into the nearby Animas River, turning it a yellow for dozens of miles crossing state lines.

Five easy-to-find examples that impacted a lot of people, but it does not address the obvious question – WHY are these sites next to rivers?  Why isn’t this material moved to more appropriate locations?  It should never be stored on site, next to water that is someone else’s drinking water supply.  USEPA and state regulators “regulate” these sites but regulation is a form of tacit approval for them to be located there.  Washington politicians are reluctant to take on these interests, to require removal and to pursue the owners of defunct operations (the mine for example), but in failing to turn the regulators loose to address these problems, it puts our customers at risk.  It is popular in some sectors to complain about environmental laws (see the Presidential elections and Congress), but clearly they are putting private interests and industry before the public interest.  I am thinking we need to let the regulators do their job and require these materials to be removed immediately to safe disposal.  That would help all of us.

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