population growth

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 .

DSCF0032Curtailed water use and conservation are common topics of conversation in areas with water supplies limitations.  As drought conditions worsen, the need for action increases, so when creating a regulatory framework, or when trying to measure water use efficiency, water supply managers often look for easily applied metrics to determine where water use can be curtailed.  Unfortunately, the one-size-fits-all mentality comes with a potential price of failing to fully grasp the consequences decision-making based on such metrics.

One of the issues that water supply regulator like to use is per capita water use.  Per capital water use is often used to show where there is “wasted” water use, such as excessive irrigation.  However such a metric may not be truly applicable depending on other economic factors, and may even penalize successful communities with diverse economic bases.  A heavy industrial area or dense downtown commercial center may add to apparent per capita use, but is actually the result of vibrant economic activity. Large employment centers tend to have higher per capital use than their neighbors as a result of attracting employees to downtown, which are not included in the population.

In south Florida, a recent project I was involved with with one of my students showed that while there was significant variability among utilities, but the general trend of increased economic activity was related to increased per capita use.  Among the significant actors were health care, retail trade, food service and scientific and technical services.  It appears to be these sectors that drive water use upward.  As a result when evaluating the efficiency of a utility, an analysis should be conducted on the economic sectors to insure that water regulations do not stifle economic growth and jobs in a community.   And conversely if you do not have these sectors, you water use should be lower.  Something to think about when projecting or regulating water use.  Limited water use may in fact be limiting economic activity in the area. Of course if you are water limited, limited new withdrawals may be perfectly acceptable if you want to encourage other options, like direct or indirect potable reuse, irrigation, etc.  

It would be interesting to expand this study across the country to see what the national trends look like and how different tourism oriented South Florida might actually be.


Water and wastewater utilities spend a lot of time dealing with current issues =- putting out “fires.”  But there are larger trends that will affect the industry.  Here are a couple recent topics that we should consider in our industry:

Will robots be doing all our repetitive jobs?  If so what does that mean for all the people doing those jobs now.  Most do not require a lot of skills, and many of those in the jobs that will be lost, do not have the skills for other jobs?  Does the $15 per hour minimum wage accelerate this transition?  How does this affect the water industry?  Meter readers might be replaced with AMR systems.  Customer service is already migrating to direct banking.  There is a change coming.

What does the driverless car mean for us?  I am thinking about an old Arnold Schwartzenegger movie.  For utilities the issue may be how we interact with unmanned vehicles, especially when what we do can be disruptive to traffic.  What happens if those cars get into an accident?  And Warren Buffett is thinking about the impact of this on the insurance industry.  He owns a lot of GEICO stock.  It is doubtful many utility vehicles will be unmanned, in the near-term, but do our manned vehicles and the potential disruption leave us open to greater risk of loss?

Speaking of Warren Buffett says the economy is far better than certain candidates suggest.  I tend to trust Mr. Buffett.  He’s been doing this a long time and has been fabulously successful.  But he notes structural changes to the economy like those noted above, are ongoing.  That will create conflict for certain professions that migrate to automation, much as manufacturing did in the 1970s.  He raises concern about what happens to those workers and suggests that we have not planned enough for those workers who get displaced as the economy undergoes continuing transitions.  In the late 1970s we had CETA and other jobs training programs as we moved from manufacturing to other jobs.  He does not see that in place now.  The at-risk – the poor, minorities, the less educated, rural citizens…. in other words, the usual groups will be hit harder than the rest of the population.  I don’t hear that discussion on the campaign trail but utilities may want to follow these trends is the hope that we can acquire some of the skillsets that we need.  Or provide that training.

Florida’s flood protection plan received a C- from a study called States at Risk.  It said Florida lacks a long term plan for rising seas, despite being vulnerable.  On an unrelated note, the state is expecting insurance premiums to increase 25% or more for flood insurance for homeowners.  And local officials are working busily on FEMA maps to exclude as many properties as possible from flood insurance requirements.  Maybe those things are all related, just at opposite purposes, but who is going to get the calls when flooding occurs?  Storm water utilities, and sewer systems where the manholes are opened to “facilitate drainage.”  The question is what the ratings are for other states as Florida was not the least prepared nor is it the only state with exposure.

A final current trend to think about is this:  Current sea level rise projections have increase the high end, but remained steady for the 50 percentile case.  By 2200 we may see seas at 10 ft higher. That would be a major problem for south Florida.  But the world population will be over 15 billion, which exceeds the carrying capacity of agriculture (at present projections and techniques).  It also places over half the world in water limited areas.  So sea level rise is going to be huge in south Florida, but will concern be localized because of more pressing issues?   Is the number of people going to be our biggest issue in 2200?  Note both will be critical for a large portion of those 15 billion people, but the solution to either is…..?


photo 2A week or so ago, on a Sunday afternoon, I flew across Middle America to Colorado for a meeting and was again struck by the crop circles that dominate the landscape west of the Mississippi River.  They are everywhere and are a clear sign of unsustainable groundwater use.  I recently participated in a fly in event for National Groundwater Association in Washington DC, where several speakers, including myself, talked about dwindling groundwater levels and the impact of agriculture, power and economies.  The impact is significant. Dr. Leonard Konikow, a recently retired USGS scientist, noted that he thinks a portion of sea level rise is caused by groundwater running off agriculture and from utilities and making its way to the ocean. He indicated that 5% of SLR each year was caused by groundwater runoff, and has upped his estimates in the past 10 years to 13%.  This is because it is far easier for water to runoff the land than seep into rocks, especially deep formations that may take many years to reach the aquifer.  And since ET can reach 4 ft below the surface, many of the western, dry, hot areas lose most of this water during the summer months.  Hence the impact to agriculture, and the accompanying local communities and their economies will be significant.

It should be noted that the US is a major exported of food to much of the world, including China, so the impact on our long-term economic trade may be significant.  Fortunately the power industry has historically preferred surface waters, but must as power demands increase, they have begun to explore groundwater in rural areas without access to surface waters.  Keep in mind that air-cooled power plants are 25% or more less efficient than water cooled systems and many of these communities lack sufficient reusable water supplied to substitute for cooling.  Hence the projection is a long term negative impact on all of us.

So the question is why isn’t the federal government talking more about this problem?  Is it fear of riling up local political officials that see growth at all costs as necessary?  It is private rights arguments that may spawn lawsuits?  Is it a lack of interest in long-term?  Or the idea that “we have always found a way”. Or is it just buried heads in the sand, leaving the next generation to deal with the problem?  A big issue, yet we do not talk enough about it.  Maybe this is not a surprise since we have not gotten very far with the discussion of limited oil, precious metals, phosphorous or other materials, and unlike them, water appears to be renewable globally.  But water is location specific.  If you have it, great.  If you lose it, a problem.  There are several recent journal articles that make the argument that much of the strife in the Middle East and Africa is water depletion related: water depletion kills local economies.  So we need to ask –what happens if we ignore the looming crisis?  Do we create more “Bundy-type” actions in the rural, dry west because they already lack water?  I suggest it is a cause for concern.

photo 2Over the holidays there were a couple articles that came out about groundwater issues in the US, mostly from the declining water level perspective.  I also read a paper that suggested that rising sea level had a contribution from groundwater extraction, and of course USGS has maps of areas where the aquifer have collapsed as a result of overpumping.  In 2009 USGS published a report that showed a large areas across the country with this issue.  The problem is that of the 50,000 community water systems in the US, 500 serve over 50% of the population, and most of them are surface water plants.  There are over 40,000 groundwater systems, but most are under 500 customers.  Hence, groundwater is under represented at with the larger water associations because the large utilities are primarily surface water, while the small systems are groundwater. AWWA has difficulty reaching the small systems while RWA and NGWA reach out to them specifically.  But the small utility seems more oriented to finding and producing water and operating/maintaining/drilling wells than the bigger impact of groundwater use.  It is simply a matter of resources.  I ran a system like that in North Carolina, and just getting things done is a huge issue.  A couple of my medium size utility clients have the same problem.

The bigger picture may contain the largest risk.  Changing water supplies is a high cost item.  We have seen a couple examples (surface water) as a result of drought.  We saw Wichita Falls and Big Springs TX go the potable reuse route due to drought.  California is looking at lots of options. Both have had rain lately (Wichita Falls discontinued the potable reuse when the reservoir got to 4% of capacity).  Great, but someone is next.  Droughts come and go, and the questions is how to deal with them.

Groundwater supposedly is a drought-proof problem, but is it?  Groundwater has been a small utility solution, as it has been for agriculture.  But aquifer require recharge and water limited areas do not have recharge.  The result is a bigger problem – overpumping.  Throughout the west/southwest, Plains states, upper Midwest (WI, MN, IA), southeast (SC, NC), we see this issue.  Most of these areas have limited surface water so never developed much historically.  Rural electrification changes that because it made is easy to put in an electric pump to pull water out of the ground in areas that never had a lot of water on the surface, and hence were not farmed much. Pumps made is easier to farm productively, which led to towns. However, our means to assess recharge are not very good, especially for confined aquifers. The lowering water levels USGS and state agencies see is an indication that recharge is normally over estimated giving a false picture of water availability.  If your aquifer declines year after year, it is not drought – it is mining of the aquifer. You are sucking it dry like the eastern Carolinas did.  But, like many negative things, there is a lack of willingness to confront the overpumping issue in many areas. There are many states with a lack of regulations on groundwater pumping.  And I still think groundwater modeling use is limited to larger utilities, when smaller, rural systems may be most in need of it due to competing interests.

Concurrently, I think there is a tendency to oversell groundwater solutions (ASR, recharge), groundwater quality and the amount of available water (St George, UT).  Easy, cheap, limited treatment should not be the only selling point.  That leads to some curious decisions like some areas of California north of LA the utilities do not treat hard groundwater – then tell residents they cannot use softeners because of the salt in the wastewater prevents it from being used for reuse.  The reason they do not treat – cost, but it makes things difficult for residents.  The fact is we do not wish to confront is the realization that for many places, groundwater should probably be the backup plan only, not the primary source.

That leads to the question – what do we do about it when every politician’s goal is for their community to grow?  For every farmer to grow more crops?  But can they really grow sustainably?  DO we not reach a point where there are no more resources to use?  Or that the costs are too high?  Or that competition become unruly?  The growth and groundwater use ship is sailing, but in to many cases they do not see the rocks ahead.

The most recent issue of the magazine Population Connection notes several interesting things.  First, the world’s population grows by 80 million people per year, predominantly in areas that are not “first World” countries.  In many of these places water is limited – 1.2 billion people live in these areas. By 2030, 40% of the people, especially those in these areas will be facing water deficits that will increase their risks.  Some of these deficits will be exacerbated by climate changes.  Agriculture is responsible for 70% of water use, and that number is not expected to decline as the need for agricultural products increases with time.  So clearly water use and population are related, just as carbon dioxide concentrations in the atmosphere and population appear to be related. Worse yet, the number of urban residents that do not have access to wastewater services is expected to increase by 50%.  The good news, not so much in the US, where such services are expected and available to the vast majority of people.  So the problem – most of these people live in Third World countries that lack both the economic resources and social infrastructure to deal with these problems.  This is what Engineers Without Borders is trying to address but it does raise that question – what are the social consequences of trying to help them?  Surely engineering ethics say we should help protect the public health, safety and welfare, which this work does.  But on the other side, if they develop more and add more people, does that add to the strain on limited resources in these areas which might damage the public health safety and welfare.  Which is the more critical issue?  And how do we decide? How should engineers evaluate the conflict between public health and sustainability from an ethics perspective? Just asking?

%d bloggers like this: