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Disinfectant Byproducts Are the Most Common Water System Violations

In 2016, there were 2,733 public water supply systems in Missouri. In the previous post, I reported that 94.7% of the population received water from suppliers that had no violations of safe drinking water standards during the year (it has decreased from 95.7% in 2012). This means that 5.3% of the population was served by systems that did have a violation. As Missouri’s population in 2016 was 2,093,000, that means that almost 111,000 people were served water systems that had a violation during the year. This post looks into the nature of the violations.

In 2007 and 2010 there was an increase in the population affected by a violation. The cause in 2007 was an error in backwashing a filter at the Missouri American Water Company South Plant in St. Louis County. The error caused a spike in turbidity that lasted four minutes. During that time the water reached an estimated 24,578 customers, though no reports of illness were associated with this event. Even though only some customers were affected, federal documentation rules require that the entire service population be reported as exposed. In 2010, “the same phenomenon happened again.” (2012 Annual Compliance Report of Missouri Public Drinking Water, p. 4)

A violation does not indicate that public health was affected, but it creates the potential for a public health impact to occur. For this reason, violations are important administrative markers. The DNR monitors two broad kinds of violations. Water contaminants (chemicals and bacteria) can exceed their respective maximum concentration levels (health-based standards), or a water system can fail to meet adequate administrative standards (most often not performing and reporting the water quality tests required by law).

Figure 1 at right shows the percentage of the population served by community water systems that had different types of health-based violations in 2016. Violations of the Stage 1 & 2 DBP Rule were by far the most common, affecting about 3% of the population. (In the chart, Excel has rounded to the nearest full percent.) Figure 2 compares the data for 2013 and 2016.

(For larger view, click on figure.)

Figure 1. Data source: Missouri Department of Natural Resources, 2016.

Figure 2. Data source: Missouri Department of Natural Resources, 2016.

 

 

 

 

 

 

 

 

 

 

In previous years, the most common type of violation had to due with coliform bacteria. The text of the report indicates that in 2016 coliform contamination continued to represent the most common kind of violation. However, as shown in Figures 1 and 2, violations of the Stage 1 & 2 DBP Rule affected more of the population than did coliform contamination. Let me explain what this means.

Coliform bacteria are a family of bacteria that live naturally in the soil, and which also live naturally in the guts of many animals, including humans. Consequently, it is not uncommon for some coliform bacteria to get into water supplies. Most coliform bacteria are safe, but a few species of coliform bacteria (including some E. coli) can cause illness in humans. In addition, because they live in great numbers in the guts of humans and animals, their presence in large numbers serves as a sign of fecal contamination. Human and animal feces contain many species of harmful bacteria, and the presence of too many coliform bacteria serves as a marker that these other bacteria might be present, too.

Over the years, the EPA has lowered the maximum allowable level of coliform bacteria concentration in drinking water, and water systems have had to increase their treatment of the water to kill the bacteria. The treatment usually occurs in stages. Unfortunately water often contains organic matter, such as algae or dissolved plant material. If the water treatment is not done properly, the chemicals used to kill the bacteria react with the contaminants to form byproducts that can also be harmful. The Stage 1 & 2 DBP (Disinfectants and Disinfection ByProducts) Rule requires water systems to monitor the level of such byproducts in their water. Thus, it may be because water systems are using additional treatment to kill bacteria that decreasing coliform contamination and increasing violations of the Stage 1 & 2 DBP rule are occurring.

The presence of E. Coli or of other species of coliform bacteria remains the most serious violation, in the Department’s opinion. Thus, the presence of either results in a boil order. All water systems in Missouri are required to test for E. Coli. Nineteen systems received boil orders in 2016. That number has been moving mostly sideways since 2012, but represents a decrease from 32 in 2011. Most lasted for a few days up to two weeks, but some lasted for several months.

Seventy-four systems had chemical violations, almost all for trihalomethanes . Trihalomethanes are water treatment byproducts. They form if disinfectants used to treat the water (chlorine or bromine) react with matter that may be present in the water (e.g. decaying vegetation).

Eleven systems had violations involving excess radiological contaminants (down from 14 systems in 2012 and 16 systems in 2011). The problems came from several radiological elements, see the report for full details.

In 2016, 7 water systems had Surface Water Rule violations, the same as in 2013. All of the violations were for combined filter effluent turbidity. Systems must filter surface water to remove cryptosporidium, a parasite that causes diarrhea, and a violation of the turbidity rule means the filtering may not be adequate to remove the parasite.

As noted above, some of violations can be quite brief, and the threat they represent to public health can be small. However, the DNR puts a special focus on water systems that repeatedly fail to meet monitoring standards, and on those with a routine sample that tests positive for coliform, but which fail to submit follow-up or repeat samples as required.

As reported in the previous post, 38 water systems were listed as having had three or more major monitoring violations in 2016 (up from 27 systems in 2013). Many of them were in violation for many months. Figure 3 shows the list. Only 6 water systems had water that tested positive for excess coliform bacteria, but failed to provide the required follow-up samples for testing. This represents a decrease from 47 systems in 2013. Figure 4 shows the list.

Figure 3. Source: Missouri Department of Natural Resources, 2016.

Figure 4. Source: Missouri Department of Natural Resources, 2016.

 

 

 

 

 

 

 

 

 

 

 

 

Sources:

Missouri Department of Natural Resources. 2013 Annual Compliance Report of Missouri Public Drinking Water Systems. https://dnr.mo.gov/env/wpp/fyreports/index.html. Published 2014-11-18.

Missouri Department of Natural Resources. 2016. Annual Compliance Report of Missouri Public Water Systems. Downloaded 5/11/2018 from https://dnr.mo.gov/env/wpp/fyreports/index.html.
Missouri Census Data Center. Population Estimates for Missouri. Viewed online 6/28/2018 at http://mcdc.missouri.edu/trends/estimates.shtml.
Wikipedia contributors. (2018, May 15). Trihalomethane. In Wikipedia, The Free Encyclopedia. Retrieved 22:26, July 5, 2018, from https://en.wikipedia.org/w/index.php?title=Trihalomethane&oldid=841446641

Most Public Water Systems Met All Health-Based Regulations in 2016

The previous post reported that the Census of Missouri Public Water Systems – 2016 found 2,733 public water systems in Missouri, of which 2,720 were active. This post looks at Missouri’s 2016 Annual Compliance Report of Missouri Public Drinking Water Systems. It is the most recent summary report on Missouri’s public water systems. Additional detail about specific systems can be found in reports published by the systems themselves.

A public water system is one that provides water to at least 15 service connections, or to an average of at least 25 people for at least 60 days each year. Community Systems (CWS) supply water to the same population year-round. Non-Transient Non-Community Water Systems (NTNCWS) supply water to at least 25 of the same people at least 6 months per year, but not year-round. An example might be a school that has its own water system. Transient Non-Community Water Systems (TNCWS) provide water in places where people do not remain for long periods of time. Examples might include gas stations or campgrounds that have their own water systems.

The amount of treatment that water must receive differs depending on the source of the water. Surface water and underground water under the direct influence of surface water are more vulnerable to contamination, so they receive more treatment. Underground water from aquifers not under the direct influence of surface water tend to contain water that is heavily filtered by the rock through which it seeps. Sometimes, the seepage is so slow that the water is old, predating most forms of modern contamination.

Figure 1. Source: Missouri Department of Natural Resources, 2016.

Figure 2. Source: Missouri Department of Natural Resources, 2016.

 

 

 

 

 

 

 

 

Figure 1 shows the percentage of population served by community water systems that meet all health-based requirements by year. Figure 2 shows the number of violations involving E. Coli or acute contamination levels. Non-compliance can result from many factors from broken pipes, to human error, to systems that are inadequate in the first place. The EPA goal is for 95% of the public water systems in a state to have no health-based violations in a year. In 2016, Missouri had 94.7% compliance. That is close to the goal, but it is a decrease from over 95% in 2013. The chart shows no general trend, but in some years the compliance rate appears to slip significantly. The last 3 years have all been below the EPA goal.

The number of violations for E. coli and acute MCL violations (maximum contaminant level violations – also mostly due to coliform contamination) peaked in 2008 and had another bad year is 2011. Since 2012, it has mostly been moving sideways. In 2016, there were 19 violations.

Ninety-four-point-seven percent is a high mark – you would have been happy to score 94.7% on tests at school, wouldn’t you? Since Missouri’s population in 2016 was 2,093,000, however, it means that water systems serving almost 111,000 people had a health-based violation. (Missouri Census Data Center)

In 2016, 38 public water systems had 3 or more “major monitoring violations” of the rules to protect against coliform contamination. That is an increase from 27 in 2013. Monitoring violations are a concern because hinders the Department of Natural Resources’s ability to determine if the drinking water is safe, especially if the monitoring violation occurs multiple times.

In 2016, however, there were only 6 major “repeat monitoring violations,” down from 41 in 2013. A repeat monitoring violation occurs when If a routine sample from a public water system tests positive for coliform bacteria, then the system is required to submit a second test to confirm the finding, and to conduct follow up testing to ensure that the problem is eliminated. A repeat monitoring violation occurs when the system fails to submit the repeat testing or follow up testing.

None of these violatios mean that people were actually sickened, the report does not address that issue. It does mean, however, that a potential vulnerability occurred, and that continuing work needs to be done to ensure that Missourians have safe drinking water.

The next post will look into the nature of the violations that occurred.

Sources:

Missouri Census Data Center. Population Estimates for Missouri. Viewed online 6/28/2018 at http://mcdc.missouri.edu/trends/estimates.shtml.

Missouri Department of Natural Resources. 2016. Annual Compliance Report of Missouri Public Water Systems. Downloaded 5/11/2018 from https://dnr.mo.gov/env/wpp/fyreports/index.html.

Census of Public Water Systems, 2018

Each year the Missouri Department of Natural Resources publishes the Census of Missouri Public Water Systems. I reported on the 2013 census here, and the 2014 census here, and the 2015 census here. This post reports on the 2016-2018 censuses. The census provides basic information about the number and type of public water systems in the state, plus information on each system that includes the source of its water, the type of treatment it gives the water, and a chemical analysis of the water that covers 16 inorganic chemicals.

The EPA defines a public water system as one that provides water for human consumption to at least 15 service connections or that serves an average of at least 25 people for at least 60 days a year. It classifies public water systems in three categories. Community Water Systems (CWS) supply water to the same population year-round. Non-Transient Non-Community Water Systems (NTNCWS) supplies water to at least 25 of the same people at least 6 months per year, but not year-round. An example might be a school that has its own water system. A Transient Non-Community Water System (TNCWS) provides water in a place where people do not remain for long periods of time. Examples might include gas stations or campgrounds that have their own water systems. Not included in the report are private systems, such as a privately owned well that provides water only to its owner.

Table 1 shows the number of public water systems in Missouri by category. In 2018 there were 2,732 public water systems in Missouri, about 52% of which were community water systems. The numbers have not changed greatly over the years.

Table 1.

Table 1. Data source: Missouri Department of Natural Resources, 2013 through 2018.

A primary water system is one that obtains water from a well, infiltration gallery, lake, reservoir, river, spring, or stream. A secondary water system is one that obtains its water from an approved water system, and distributes it to consumers. (Missouri 10 CSR 60-2015, Definitions) For instance, in 2018 the St. Louis City Public Water System was a primary system. It obtained 100% of its water from surface water supplies, and treated the water itself. On the other hand, the Kirkwood Public Water System was a secondary system. It purchased 100% of its water from Missouri American Water, which treated the water before selling it to Kirkwood. Kirkwood only distributes the water.

In 2018, about 78% of Missouri public water systems were primary systems, and they served about 79% of the population. Table 2 shows the number of systems by water source, and Table 3 shows the population served by each type.

Table 2.

Table 2. Data source: Missouri Department of Natural Resources, 2013 through 2018.

Table 3.

Table 3. Data source: Missouri Department of Natural Resources, 2013 through 2018.

Groundwater means groundwater that is not directly influenced by the surface water above it. The groundwater is isolated from surface groundwater by thick layers of rock or sediment that filter the ground water before it reaches the groundwater aquifer. Such groundwater is often considered less vulnerable to pollution by chemicals and organic waste. Groundwater Under Direct Influence refers to groundwater that is not protected from the surface water above it, and which consequently contains groundwater contaminants, such as chemicals, insects, microorganisms, algae, or turbidity. This kind of water requires more extensive treatment before it is fit for use. So does surface water. Groundwater is a limited resource, however, that sometimes takes hundreds, if not thousands, of years to percolate into underground aquifers. Overuse can deplete it. (See here.)

In 2018, groundwater systems constituted 84.5% of the total number of systems, but they served only 37.1% of the population. On the other hand, surface systems constituted 15.2% of the systems, but served 62.4% of the population. Table 3 shows the population served by water source.

Most of the water systems in Missouri source their water from groundwater, only a few from ground water under direct influence. However, the source serving the largest population is surface water. Specifically, the Missouri River is the water source for much of the Kansas City and St. Louis metropolitan areas. More than half of Missouri’s population is served by water either from the Missouri River Alluvial Aquifer or water from the river itself.

Source:

Missouri Department of Natural Resources. 2013. 2013 Census of Missouri Public Water Systems. Downloaded 2018-06-13 from https://dnr.mo.gov/env/wpp/census.htm.

Missouri Department of Natural Resources. 2014. 2014 Census of Missouri Public Water Systems. Downloaded 2018-06-13 from https://dnr.mo.gov/env/wpp/census.htm.

Missouri Department of Natural Resources. 2015. Census of Missouri Public Water Systems, 2015. Downloaded 2018-06-13 from https://dnr.mo.gov/env/wpp/census.htm.

Missouri Department of Natural Resources. 2016. 2016 Census of Missouri Public Water Systems. Downloaded 2018-06-13 from https://dnr.mo.gov/env/wpp/census.htm.

Missouri Department of Natural Resources. 2017. 2017 Census of Missouri Public Water Systems. Downloaded 2018-06-13 from https://dnr.mo.gov/env/wpp/census.htm.

Missouri Department of Natural Resources. 2018. 2018 Census of Missouri Public Water Systems. Downloaded 2018-06-13 from https://dnr.mo.gov/env/wpp/census.htm.

Missouri’s Major Power Outages

For several posts I have been reporting on the bulk power grid in the United States. The Grid, as I have been calling it, delivers high voltage electricity from generating stations to local distributors. The local distributors step the voltage down and deliver the electricity to individual customers. Ameren, for instance, claims to own 7,500 miles of transmission lines (Ameren, undated), while Great Plains Energy (parent of Kansas City Power & Light) claims to own 3,600 miles (Westar & Great Plains Energy, 2018).

In the past, relatively small problems at specific locations on The Grid have cause cascading failures that left tens of millions of customers without power. The North American Reliability Corporation (NERC) publishes an annual reliability report, in which they evaluate the kinds of problems that been related to those types of grid collapses: electricity demand, generating capacity, transmission capacity, and operating procedures. I reported on the conclusions of that report in the last 2 posts.

Missouri has not been caught-up in those grid collapses. Widespread power outages in Missouri have been caused by severe weather. Both summer and winter storms have brought down large parts of local transmission grids.

For security purposes, the U.S. Department of Energy requires utilities to file reports of electric incidents and emergencies affecting The Grid. These reports cover much of the local distribution system, as well as the bulk power system we have been discussing in previous posts. These reports are known as OE-417 reports. They include major power outages, but they also cover things like vandalism and sabotage, even if they don’t result in a loss of power to any customers. Large utilities are required to submit the reports, but smaller utilities must file only “as appropriate.” (Department of Energy, undated.)

Table 1. Data source: Inside Energy, 2014, and U.S. Department of Energy, undated.

Inside Energy, an organization that studies the reliability of The Grid, put together a database from these reports that covers the years 2000-2014 (Inside Energy, 2014). To that database, I have added the Department of Energy data for the years 2015, 2016, and 2017, creating a database that lists events from 2000-2017. I then selected only those events in which the area affected included “Missouri,” “St. Louis,” or “Kansas City.” It is as comprehensive a database of events affecting Missouri as I can put together, though given the limits in the reporting requirements, it is not completely comprehensive. It probably catches all large power outages, but may not capture some of the smaller ones.

For a widespread power outage, what is your definition of widespread? Table 1 lists the individual events, gives a brief description of the kind of event it was, and shows how many customers were affected. In reading this table, be sure to note that many of the events affected more than one state. Thus, some of the customers affected may have been in other states.

(Click on table for larger view.)

While there have been large events, none of them match the scale of the events that plunged tens of millions of customers into darkness in the Northeast. The largest event occurred in 2006, when severe summer storms caused 2,500,000 customers to lose power in the Greater St. Louis Area (including Illinois). Anybody remember that one? I sure do. While that was less than 1/10th of the number of people affected by the Great Northeast Blackout of 2003, it was a very major event!

Figure 1. Data source: Inside Energy, 2014, and U.S. Department of Energy, undated.

The table shows 30 events overall, but none prior to 2002, and none from 2003-2005. Was that really the case? I don’t know. I have previously reported on the dollar value of weather-related damage in Missouri, and while 2004 and 2005 were very low damage years, 2000, 2001, and 2003 were not (see here). Thus, one wonders if there are holes in the data. Overall, there were on average 1.67 electrical disturbances per year.

Figure 1 charts the number of disturbances per year. While there is a lot of yearly variation (the weather is always variable from year-to-year) there is a clear trend toward an increased number of outages per year.

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Figure 2. Data source: Inside Energy, 2014, and U.S. Department of Energy, undated.

Figure 2 charts the number of customers affected per year. The chart is dominated by the very large event of 2006, but even if you eliminate that one year, the chart does not seem to show a clear trend toward an increased number of customers affected.

Given that damage from weather-related events in Missouri has increased over time, and that the number of outages has increased over time, one is tempted to guess that utilities have made progress in protecting at least some parts of their distribution networks from large scale outages. One can’t be sure from this data, however, it would be an interesting topic for additional research.

The Missouri State Emergency Management Agency prepared a Missouri State Hazard Mitigation Plan in July of 2013, and the analysis in that plan suggests that power outages are not inconsequential. Many essential services rely on electrical power. For instance, many of the life-support systems in hospitals require electricity, pumps that deliver drinking water run on electricity, and the refrigerators that keep our food from spoiling do, too. Further, I have reported previously on deaths caused by extreme heat waves, and some of those deaths result from the loss of air conditioning due to power outages.

The Agency estimated that total loss of electric power results in dollar damages of $126 per person affected, per day. Multiplying that by the estimated population of each county, their estimates ranged from a low of $27,355 per day in Worth County to a high of $12,5865,820 per day in St. Louis County. (Missouri State Emergency Management Agency, 2013, pp. 3.542-3.547) These are damages that could mount-up very quickly.

Thus, the electrical grid is something we all use every single day, and our very lives depend on it. It is a huge, complex, interconnected machine. Its reliability seems an issue vital to our lives and to our security.

Sources:

Ameren. Undated. Ameren Facts and Figures. Viewed online 5/21/2018 at https://www.ameren.com/about/facts.

Inside Energy. 2014. Grid Disruption 00 14 Standardized. Downloaded 5/9/2018 from https://docs.google.com/spreadsheets/d/1AdxhulfM9jeqviIZihuODqk7HoS1kRUlM_afIKXAjXQ/edit#gid=595041757. This is a Google Spreadsheet linked to Data: Explore 15 Years of Power Outages. Viewed online at http://insideenergy.org/2014/08/18/data-explore-15-years-of-power-outages.

Missouri Satate Emergency Management Agency. 2013. Missouri State Hazard Mitigation Plan, July 2103. Downloaded 5/24/2018 from https://sema.dps.mo.gov/docs/programs/LRMF/mitigation/MO_Hazard_Mitigation_Plan_2013.pdf.

United States Department of Energy. Undated. Electric Disturbance Events (OE-417). Viewed online 2018-06-04 at https://www.oe.netl.doe.gov/oe417.aspx.

Westar Energy & Great Plains Energy. 2018. Merger to Form Leading Company: January 2018 Investor Update. Viewed 5/21/2018 at http://www.greatplainsenergy.com/static-files/b8b91848-48a6-4f88-8fd3-df3b59316b96.

Future Grid Resources in Missouri

In my last post I looked at the 2017 Long-Term Reliability Assessment issued by NERC, the North American Electric Reliability Corporation. In that post, I focused on a grid-wide perspective. In this post, I’ll offer a few conclusions in the report that pertain to Missouri.

In the northeastern USA, the largest power outages have been caused by relatively small failures at specific locations that caused underloads or overloads, which then cascaded into region-wide outages. They have affected tens of millions of customers. Consequently, the 2017 Long-Term Reliability Report focuses on the kinds of issues involved in those blackouts: electricity demand, generating capacity, transmission capacity, and operating procedures.

In Missouri, however, the largest power outages have been caused by storms that destroyed transmission lines, most of which are in the local transmission grid. (See Electrical Outages from Storms Increase.) The 2013 Long-Term Reliability Assessment does not cover the local transmission grid, and it does not seek to evaluate the potential for damaging storms. Thus, the findings of the report deal with important planning issues for The Grid in Missouri, but they don’t address the historical reasons for our power outages. I will look at weather-related power outages in Missouri in the next post.

Figure 1. Source: North American Reliability Corporation 2017.

The resource adequacy of Missouri’s grid depends on where you are. Some western portions of the state, including Kansas City, (see Figure 1) belong to the SPP reporting region (Southwest Power Pool). The SPP 10-year compound growth rate in demand for electricity is 0.56%. The anticipated reserve margin is projected to fall from 32.43% in 2018 to 19.85% in 2027, but remain well above NERC’s 12.00% target.

The central portion of the state belongs to the SERC-N reporting region (SERC Reliability Corporation–North). The SERC-N 10-year compound growth rate in demand for electricity is projected to be 0.38%. The anticipated reserve margin is projected to fall from 21.45% to 17.18% in 2027, still above NERC’s 15.00% target.

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Figure 2. MISO Projected Capacity Reserve. Source: National Electrical Reliability Organization 2017.

A portion of eastern Missouri belongs to the Midwest Independent Service Organization (MISO) reporting region, including the St. Louis Metropolitan Region. The MISO 10-year compound annual growth rate is 0.28%. Though starting at 19.23% in 2018, the reserve margin level will fall below the Reference Margin Level (15.80%) in 2023, and will reach 14.56% by 2027. In fact, despite projected growth in demand, generating resources are projected to decline slightly. Figure 2 shows a graphical representation of the projection, with anticipated reserve in dark blue (anticipated reserves are based on plans announced by utilities), and prospective reserve in light blue (prospective reserves are based on potential plans discussed by utilities, but not announced).

These conclusions are more hopeful than those reached in the 2013 Long-Term Reliability Report. The primary reasons are that demand growth is projected to slow, fewer power plant retirements are projected to occur, and utilities have become better at forecasting demand and outages. That notwithstanding, we have entered a period of uncertainty with regard to our national bulk electricity grid. A few years ago legislation made it mandatory for all participants in The Grid to participate in NERC, and it gave NERC regulations the force of law. These changes hold out the potential for increased reliability and improved operations. On the other hand, many factors combine to represent threats to the long-term reliability of The Grid: aging infrastructure, environmental regulations that will force the retirement of coal-fired generating capacity, the retirement of nuclear generating capacity that has reached the end of its useful life, new generating sources that provide constantly varying amounts of power to The Grid, and uncertainty surrounding demand side management programs.

Resource adequacy in western and central Missouri is projected to be adequate through 2027. In eastern Missouri, reserves are projected to fall below the target level by 2023, and continue to edge lower through 2027. I will look at weather-related power outages in Missouri in the next post.

Source:

North American Electric Reliability Corporation. 2013. 2013 Long-Term Reliability Assessment. http://www.nerc.com/pa/RAPA/ra/Reliability%20Assessments%20DL/2013_LTRA_FINAL.pdf.

North American Electrical Reliability Corporation. 2017. 2017 Long-Term Reliability Assessment. Downloaded 4/27/2018 from https://www.nerc.com/pa/RAPA/ra/Pages/default.aspx.

Long-Term Reliability of the National Electrical Grid

The previous 5 posts have described the national electrical grid, how electricity flows on The Grid, how it is organized, Missouri’s portion of The Grid, and the complex balancing act that operators of The Grid face every day. Finally we’re in a position to look at the 2017 Long-Term Reliability Assessment. This is an annual report published by NERC, the North American Electric Reliability Corporation. The assessment identifies several main threats to long-term reliability:

  1. The increasing mix of variable generation may present operational and planning challenges. Let me explain. We saw in the previous post that operating The Grid is a complex balancing act: enough electricity has to be delivered to meet demand, but operators have to be careful not to damage The Grid by flowing either too much or too little electricity through any one part of it. In this balancing act, generating stations that supply ever-changing amounts of electricity complicate the balancing act. It is like a high wire aerialist: if there is a constant wind that is not too strong, he might be able to compensate for it. But if the wind starts gusting strongly, he is in real trouble!
    Yet, that is precisely what wind and solar energy do – the amount of energy they deliver varies with the wind and with the clouds. We need these kinds of power sources to reduce GHG emissions, and they represent an ever-increasing portion of the energy supplied to The Grid. But the challenge of managing these constant fluctuations poses a threat to Grid reliability that will have to be managed. Specifically, operators need flexible generating sources that can increase or decrease the amount of electricity they generate quickly. As California derives a larger percentage of its electricity from intermittent sources than other areas of the country, this need is largest there, and it is increasing faster than previously predicted,
  2. The Grid was designed around large central-station power plants as the primary source of electricity. Wind and solar power plants tend not to be as large. There are more of them, and they are more widely distributed. Integrating a lot of power plants is harder than integrating fewer. Accommodating them will require additions and changes to the distribution system.
  3. Resource adequacy in two reporting regions will fall below reserve margin targets. Let me explain. NERC believes that each operating region needs to maintain a generating and transmission capacity that is larger than the largest anticipated demand in order to ensure reliability. When a problem arises, the reserve is needed to make up for it. How large the reserve margin needs to be depends on the energy mix in a given region. Regions with higher intermittent energy sources require larger reserve margins. In the TRE-ERCOT region (most of Texas), generating capacity will fall below the target level by 2018. In the SERC-E region (Virginia and the Carolinas), it will fall below the target level by 2020. Neither of these regions include Missouri. Without additional generating resources, an increased likelihood of “load shedding” in these regions is possible. “Load shedding” means that they turn off electrical service to some customers or some regions in order to avoid having the whole system collapse.
  4. The growth of demand over the whole system is expected to be the slowest on record. Environmentally, this is good news. From a reliability perspective, the implications are primarily economic, and need to be managed appropriately.
  5. A transition from coal-fired power plants to natural gas-fired ones has been occurring. It will continue. The change is partial good news environmentally. Natural gas power plants produce fewer emissions than do coal-burning ones. However, as natural gas becomes a larger and larger portion of the energy mix on The Grid, the potential for interruptions in energy supply becomes more important. While current supplies seem adequate, power stations are long-term assets that last 40 years or more. For instance, Ameren’s Meramec Energy Center began operations 64 years ago, and KCP&L’s Hawthorn Power Plant began operations 65 years ago. Both are still going strong. The future supply of natural gas so far into the future is less well known than is the coal supply. This may be most important during very cold weather, when demand for natural gas for heating will be high. It may compete with demand for electrical generation, causing supply interruptions.

So, NERC works hard to identify and anticipate future stability threats to The Grid. Are they succeeding? Are outages on The Grid less common than before? That is not an easy question to answer, actually. You have to separate outages that occur on the high voltage bulk power distribution grid from those that occur on local distribution grids. And you have to factor in severe weather. It only stands to reason that years with high numbers of severe weather events will have more outages. No grid will stand up to hurricanes or tornadoes. You don’t want your grid going down every time there is wind or ice, but the 2017 Long-Term Reliability Report does not address weather-related outages.

Figure 1. Data source: Inside Energy 2014.

I found a database prepared by the Inside Energy Project. It is not a peer-reviewed source, so I have no way of assessing their methods, and it is not comprehensive, as small electricity distributors are not required to report outages. With that said, between 2000 and 2014 the database lists 1,652 outage events, affecting anywhere from 0 to 4.6 million customers. The data do not show whether the outages happened on local grids or bulk power grids. As a rough proxy, Figure 1 shows the number of outages affecting 100,000 or more customers by year. You can see that they peaked in 2011, which, amazingly, was not the year of either Hurricane Katrina or Superstorm Sandy (2008 and 2012, respectively). It was, however, the year of Hurricane Irene, a year of many tornado outbreaks, and a year of severe winter blizzards in the Northeast.

While the data is distorted by yearly weather events, there does not appear to be any strong trend toward fewer grid outages. Inside Energy actually argues that they are becoming more common, due to the factors I have discussed above, but also due to increased demand and aging infrastructure.

In the next post in this series, I will look at what NERC has to say about future grid reliability in Missouri.

Source:

Ameren Missouri. 2018. Fact Sheet. Viewed online 5/2/2018 at https://www.ameren.com/-/media/missouri-site/files/aboutus/amerenmissourifactsheet.pdf.

Gottscho-Schleisner, Inc., photographer. Hawthorn Power Plant, Kansas City Light and Power, Kansas City, Missouri. View from north I. Viewed online 5/4/2018 at the Library of Congress website, https://www.loc.gov/item/gsc1994027605/PP.

Inside Energy. 2014. Grid Disruption_00_14_Standardized. A Google Spreadsheet downloaded 5/9/2018 from https://docs.google.com/spreadsheets/d/1AdxhulfM9jeqviIZihuODqk7HoS1kRUlM_afIKXAjXQ/edit#gid=595041757. Cited in Inside Energy. 7/18/2014. Data: Explore 15 Years of Power Outages. Viewed online 5/9/2018 at http://insideenergy.org/2014/08/18/data-explore-15-years-of-power-outages.

North American Electric Reliability Corporation. 2017. 2017 Long-Term Reliability Assessment. http://www.nerc.com/pa/RAPA/ra/Reliability%20Assessments%20DL/2013_LTRA_FINAL.pdf.

What Could Go Wrong

I’ve been discussing the national electrical grid in the last several posts. If you’ve kept up, you now know that The Grid is a huge, extremely complex network of generating stations and transmission lines, and all the equipment needed to transmit electricity over those lines from the generating stations to local distribution grids.

So what could go wrong? After all, isn’t it just a bunch of wires? Nope, guess again! To function properly, The Grid needs to be precisely balanced and synchronized. In addition, The Grid handles massive amounts of energy at very high voltage. Every piece of it is designed to handle certain amounts of energy under certain conditions, or problems occur. If demand surges in one region, or if supply goes offline, then the generators in that region slow down and get out of sync, or their voltage changes and goes outside the limits they were designed to operate at. But The Grid is interconnected so that additional power can be delivered into the region from other regions, or energy can be rerouted, solving the problem before it threatens the integrity of The Grid.

The problem is that when energy is rerouted like that, unless it is precisely balanced, it has the potential to cause problems of its own. If voltage goes either too high or low, then equipment can burn out or destroy itself in various ways. When energy is rerouted, then the wires over which it is routed carry extra electricity. As electricity moves down a wire, the wire heats up. As long as the amount of electricity stays within the design range, it is okay. But if too much electricity flows through a wire, the wire gets too hot. It might burn out. Alternatively, metal expands when it heats. Thus, if the wire gets too hot, it will sag. Sagging wires are at risk of touching something underneath, creating a short, or of getting close enough that the electricity can arc to whatever is below. If a short or arc occurs, it is deadly to whatever it touches, it can melt the wire or burn out equipment up and down the system.

I wasn’t able to find any copyright-free images to share with you, but if you would like to see what arcing looks like, go to YouTube and view the videos by “Blade Runner” and “Ross Tvdoctor”. They should give you a good idea.

The demand for electricity is constantly changing. In the South it is higher in the summer than the winter (but just the opposite in northern climates), and typically it is higher during the day than at night. Grid operators have to constantly adjust and balance the electricity fed into The Grid to match the demand. They have to constantly route electricity so as to avoid overloading, and they have to reroute around local outages and problems.

Figure 1. The Empire State Building During the Northeast Blackout of 2003. Photo by Brendan Loy. Source: Flickr Creative Commons.

And finally, cities adopted different operating practices and standards as they electrified. When they interconnected into The Grid, it meant trying to integrate all of these different operating procedures and standards.

It is a tremendously complex balancing act. In Missouri, our largest power outages have occurred mostly because storms have destroyed vast portions of the local electric distribution system. (See Electrical Outages from Storms Increase.) On the other hand, the great northeast blackouts of 1965, 1977, and 2003 occurred because relatively small failures in a single spot caused underloads or overloads as energy was shunted to other parts of The Grid. These then failed, and the problem cascaded: in 2003, 55 million people were affected. (Figure 1)

Mostly The Grid is an amazingly reliable part of life. You flip a switch, and the electricity is just there. Almost always. But every now and then, it fails in a spectacular way!

NERC, the North American Electric Reliability Corporation, develops operating standards to ensure reliability. It has only had the legal authority to enforce them since 2005, however. In addition, they issue an annual long-term reliability assessment. The next post will look at findings from their 2013 report.

Sources:

Loy, Brendan. 2003. The Empire State Building in the Dark During the Great Northeast Blackout of 2003, IMG 6514. Source: Flickr Creative Commons. https://www.flickr.com/photos/brendanloy/2669855698.

Nersesian, Roy. 2007. Energy for the 21st Century: A Comprehensive Guide to Conventional and Alternative Sources. Armonik, NY: M.E. Sharpe.

“Northeast blackout of 2003.” Wikipedia. http://en.wikipedia.org/wiki/Northeast_blackout_of_2003.

Missouri and The Grid

This is the 4th in a series of posts on the national electrical grid. In previous posts I have described the components of The Grid, the National Electric Reliability Corporation’s (NERC) role in regulating The Grid, and the general flow of electricity in The Grid. This post focuses on Missouri’s position on The Grid.

Figure 1. Source: North American Reliability Corporation 2017.

NERC organizes its reliability report according to assessment regions. Missouri is divided among 3 assessment regions (Figure 1). Shown in dark blue, portions of western Missouri fall into the SPP Region (Southwest Power Pool). Shown in gray, Central Missouri, running from Arkansas to Iowa, falls into SERC-North (Southeast Electric Reliability Corporation-North). Shown in dark blue, part of Eastern Missouri falls into the MISO (Midwest Independent Service Organization).

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Figure 2. Data source: U.S. Energy Information Administration 2018a.

In 2016 Missouri was a net electricity importer. A total of 5,252,645 MWh (billion watt-hours) were imported from other states, and none were exported. Figure 2 shows that in the 1990s, Missouri was a large energy importer, then it became an exporter in 2003, but then reverted to being an importer in 2014.

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Missouri’s largest generating plants (by the amount of electricity generated) are shown in Table 1. Combined, they account for about 84% of Missouri’s net generation. For a photo and brief description of many of these power plants, see here.

Table 1: Missouri’s 10 Largest Electricity Generating Plants:

Name Owner 2016 Generation (megawatt-hours)
1. Labadie (coal) Ameren Missouri 14,792,690
2. Iatan (coal) Kansas City Power & Light 9,762,360
3. Callaway (nuclear) Ameren Missouri 9,430,179
4. Thomas Hill (coal) Associated Electrical Coop 7,120,233
5. New Madrid (coal) Associated Electrical Coop 6,760,837
6. Rush Island (coal) Ameren Missouri 6,406,193
7. Sioux (coal) Ameren Missouri 4,549,155
8. Hawthorn (coal) Kansas City Power & Light 2,704,295
9. State Line Combined Cycle (natural gas) Empire District Electric 2,308,602
10. John Twitty (coal) City Utilities of Springfield 2,096,629

(Data source: U.S. Energy Information Administration, 2018a)

Figure 3. The High Voltage Generation and Distribution System in Missouri. Source: U.S. Energy Information Administration 2018b.

Figure 3 shows The Grid within Missouri. In purple-gray it shows lines operating at 765 kilovolts all the way down to 69 kilovolts (more lines are shown in this map than in the map in the previous post because 69 kV is a lower cutoff than was used for that map). The brown lines are roads. It also shows Missouri’s generating stations by type. There are actually a fair number of natural gas generating stations, shown in blue with a white center. However, 8 of the 10 largest power plants are coal.

The largest electricity retailers in Missouri, by sales, are Union Electric (a subsidiary of Ameren Missouri), Kansas City Power & Light (a subsidiary of Great Plains Energy), KCP&L Greater Missouri Operations (a subsidiary of Great Plains Energy), Empire District Electric, and City Utilities of Springfield. Union Electric’s sales are almost 4 times those of the next largest. (Energy Information Administration, 2018a)

The low voltage distribution networks of the public utilities and electrical cooperatives throughout the state are, of course, extensive. Ameren claims to operate 7,500 miles of local transmission line, while Great Plains Energy claims to operate 3,600 miles. These posts focus on the bulk power system, however.

Sources:

Ameren. Ameren Facts and Figures. Viewed online 5/21/2018 at https://www.ameren.com/about/facts.

North American Electrical Reliability Corporation. 2017. 2017 Long-Term Reliability Assessment. Downloaded 4/27/2018 from https://www.nerc.com/pa/RAPA/ra/Pages/default.aspx.

U.S. Energy Information Administration. 2018a. Missouri Electricity Profile 2016, Full Data Tables 1-14.. Downloaded 5/10/1018 from https://www.eia.gov/electricity/state/missouri.

U.S. Energy Information Administration. 2018b. U.S. Energy Mapping System. https://www.eia.gov/state/maps.php.

Westar Energy & Great Plains Energy. Merger to Form Leading Company: January 2018 Investor Update. Viewed 5/21/2018 at http://www.greatplainsenergy.com/static-files/b8b91848-48a6-4f88-8fd3-df3b59316b96.

The Energy on the Grid

Two posts ago, I introduced you to the national energy grid. Last post I described how The Grid is organized. This post will describe some of the major energy flows along The Grid.

Figure 1 shows the major sources of electricity generated in the USA in 2017. Almost 1/3 of it was generated by burning natural gas, about 1/3 by burning coal, and about 1/3 was generated from other energy sources. Nuclear was the largest of the other sources, accounting for

Figure 1. Data source: U.S. Energy Information Administration 2018.

about 20% of total demand. Nuclear, hydro, wind, solar, and geothermal are the sources that do not emit carbon dioxide by burning fuel, so they are desirable from climate change and pollution perspectives. Together, they accounted for about 36% of total demand. Wind and solar are intermittent sources, and that has important implications for grid reliability. Together they account for about 7% of total demand.

(Click on chart for larger view.)

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Figure 2. Historical and Projected Changes in Electricity Demand. Source: North American Electrical Reliability Corporation 2017.

I described NERC, the North American Electric Reliability Corporation, in the last post. To ensure grid reliability, NERC attempts to estimate changes in demand The Grid will have to meet. Figure 2 combines historical and projected changes in demand over rolling 10-year periods from 1990 through 2027. It shows the change in demand during summer (light blue) and winter (dark blue). (In the South, demand for electricity is highest in summer, but in the North, it is highest during winter.) The columns show the change in GW (gigawatts, billions of watts) and the blue lines show the percentage compound annual growth rate.

Well, interpreting this complex graph as a little challenging, so let’s unpack it. First of all, it is a graph of change, not overall demand. So, demand for electricity has grown over every 10-year period, and it is expected to continue to do so. Second, the chart shows average annual change during each 10-year period, not cumulative change over the whole period. Third, the last period for which the data is all historical is 2007-2016. Starting with 2008-2017, some of the data is historical, some of it is projection. By 2017-2026, all of the data is projection. Fourth, the rate of demand growth accelerated in the decades starting around 2004. But fifth, the increase in demand is projected to slow in the future, in both the raw number of gigawatts and in the compound annual growth rate.

Bottom line here: The Grid is projected to have to satisfy increased demand for electricity, although the rate of growth is projected to slow.

Figure 3 shows historical additions and retirements in generating capacity supplied to The Grid, by fuel. You can see that for each type of generation, in most years, some was added and some was retired. Over the span of the chart, the net result has been a decrease in coal and nuclear generation, with an increase in natural gas, wind, and solar. Figure 4 shows similar data projected into the future. The projection shows a continuation of the trend: net retirement of coal and nuclear generating capacity, net addition of natural gas, wind, and solar. NERC projects that more natural gas generating capacity will be added than any other kind.

Figure 3. Historical Changes in Generating Capacity. Source: North American Electrical Reliability Corporation 2017.

Figure 4. Projected Future Changes in Generating Capacity. Source: North American Electrical Reliability Corporation 2017.

 

 

 

 

 

 

 

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Figure 5. Source: Department of Energy 2017.

Figure 5 shows some of this data in a form that is a bit less wonkish. It shows the location, size, and type of generating station retirements on The Grid from 2002-2016 . Triangles represent power plants owned by independent power generators, while circles represent power pants owned by vertically integrated electric utilities. Grey icons represent coal burning plants, blue icons represent natural gas burning plants, and green icons represent nuclear plants. The size of the icon represents the plant’s generating capacity. Look at the concentration of gray icons in the eastern part of the country! The retirements all occurred in a  14-year period.

Many of these plants were old and inefficient, and many of them were large spewers of GHGs and other pollutants. So, from an environmental perspective, their retirement may be good news. It doesn’t take a rocket scientist, however, to see that the retirement of so many plants represents a significant transition on The Grid.

Why does this matter? Because we are looking at reliability here, not climate change. We haven’t quite developed enough information to understand the implications yet, but we will by the end of the series of posts. At this point, we can simply say that coal-based and nuclear generating stations have proven very reliable, and they fit into The Grid nicely. NERC has concerns about the reliability of natural gas, wind, and solar generating stations for the supply of bulk electricity.

Now, what about geography?

Most electricity is generated within the NERC region where it is consumed. The flow between NERC regions is comparatively small, but because The Grid has to be so finely balanced, it is important. It flows in sometimes surprising directions. The direction is determined by many factors, including the availability of transmission lines with unused capacity, historical patterns of energy consumption, and the cost of the electricity. Inexpensive electricity generated at a distance is sometimes substituted for more expensive electricity generated locally.

The flow of energy over The Grid is shown in Figure 5 at right. The map is from 2010. The regions shown in it differ slightly from current NERC regions, and they use different names. However, it was the best representation I could find. On this map, “Midwest” = the MISO Region, “Central” = the SPP Region, “TVA” = the SERC-N Region, and “Mid-Atlantic” is roughly the PJM Interconnection Region. Let’s look a bit more closely at the map.

A region in Northern Illinois served by Commonwealth Edison belongs to the Mid-Atlantic Region, but is physically separated from it. The largest power flow in the nation occurs from this region to the rest of the Mid-Atlantic Region. This represents power that is generated by highly efficient coal and nuclear generating stations operated by Commonwealth Edison. They can’t be cycled on and off easily, so during periods of slack demand (at night) they export large amounts of power at low prices.

The second largest flow occurs from the Southwest into California. As a single state, California imports more electricity than any other.

The Midwest Region is a net exporter of power. It receives power from Manitoba and Commonwealth Edison, but it distributes even more to the TVA and Central Regions. In doing this, it participates in a counterclockwise flow from Manitoba, through the Midwest and the South, and eventually to the Mid-Atlantic Region.

The Central region is a net importer of electricity. It receives inflows from the Midwest, keeps some of it, and distributes less than it receives to Texas and the Gulf.

The amount of energy available to any region, therefore, depends mostly on the generating capacity within the region, but also on the amount it receives from other regions. The transmission of energy between regions depends not only on the need for it, but also on the availability of transmission capacity.

Sources:

Department of Energy. 2017. Staff Report to the Secretary on Electricity Markets and Reliability. Downloadedm 2018-05-19 from https://www.energy.gov/sites/prod/files/2017/08/f36/Staff%20Report%20on%20Electricity%20Markets%20and%20Reliability_0.pdf.

North American Electrical Reliability Corporation. 2017. 2017 Long-Term Reliability Assessment. Downloaded 4/27/2018 from https://www.nerc.com/pa/RAPA/ra/Pages/default.aspx.

Source: “Electricity tends to flow south in North America.” Today in Energy. EIA, http://www.eia.gov/todayinenergy/detail.cfm?id=4270.

U.S. Energy Information Administration. “U.S. Electricity Generation by Source, Amount, and Share of Total in 2017.” Frequently Asked Questions. Downloaded 4/28/2018 at https://www.eia.gov/tools/faqs/faq.php?id=427&t=3.

NERC, The North American Electric Reliability Corporation

Northeast Blackout, 2003. Photo by Brendan Loy. Source: Flickr Creative Commons.

In the last post, I gave a general description of the national electric grid. In this post, I will describe how The Grid is organized.

As we have seen in dramatic fashion several times, problems on The Grid can bring down wide areas of the whole network, plunging them into darkness and bringing life as we know it to an immediate halt.

(Click on photo at right for larger view.)

The first one of these blackouts was the famous 1965 blackout in New York. States affected included New Jersey, New York, Connecticut, Rhode Island, Massachusetts, New Hampshire, Vermont, and the Province of Ontario. Similar blackouts occurred in 1977 and 2003 (the largest of all). In response, the electric power industry formed an organization to study the problem and develop methods to prevent future occurrences. Over time, it developed into NERC, the North American Electric Reliability Corporation.

NERC does not operate The Grid. Rather, it is a nonprofit membership organization tasked with ensuring the long-term reliability of The Grid. The companies that do operate The Grid are its members, and NERC sets the standards and operating practices they must follow in order to ensure the reliability of The Grid. NERC covers the contiguous 48 states, part of Alaska, Canada except for the far north, and a small portion of Baja California. It divides its territory into 8 regional regional entities.

Until recently, membership in NERC or in one of the regional corporations was not mandatory. However, after the passage of the Energy Policy Act of 2005, NERC was designated as the only Electric Reliability Organization for the United States, and all power supplies and distributers who participate in the bulk power network were required to join.

NERC develops national standards, the Federal Energy Regulatory Commission adopts them, and they are then handed back to NERC for enforcement. They are enforceable with fines up to $1 million per day.

Figure 2. Source: North American Reliability Corporation 2017.

I noted above that NERC is divided into 8 regional entities. They administer The Grid in their territory. NERC also divides itself into 21 reporting regions. This series of posts is headed toward reporting NERC’s 2017 Long-Term Reliability Assessment, so it is the assessment areas we are most interested in. In Figure 2, I superimposed two NERC maps to show how the boundaries of the reporting regions align with state boundaries. In some cases they align well, in others, like Missouri, they don’t. In addition, some of the assessment regions have boundaries contiguous with NERC operating regions, others represent subdivisions of NERC operating regions, and still others have boundaries that follow the boundaries of Regional Transmission Organizations (discussed in the previous post).

This is all very confusing, and one wonders what is going on. Don’t think of The Grid as something that always covered all of the country. It didn’t. The idea of transmitting electricity to consumers from remote generating stations was part of The Grid from very early on. However, electrification came to cities first. Rural areas were generally thought to be difficult to electrify because the large distances required high infrastructure costs that would be born by relatively few people. This was even more the case in difficult terrain such as the Ozarks and the Appalachians. These regions were among the last to electrify.

Thus, The Grid is irregular. New electrical service areas expanded from existing service as a patchwork that followed routes of easiest access, not according to some overall plan of simplicity and symmetry. The flow of electricity through The Grid seems a bit chaotic and the boundaries of the NERC regions seem bizarre and arbitrary, but they have to do with how energy flowed into new regions from pre-existing service areas before The Grid was interconnected.

Thus, the boundaries used to make assessments are not always those used to operate The Grid, and over time, both have changed. It’s enough to drive a person crazy! And yet The Grid is amazingly reliable, and NERC is tasked with keeping it that way.

The next post will focus on major energy flows along The Grid.

Sources:

Anderson, Pamela, and Donald Kari. 2010. Is your organization prepared for complaince with NERC reliability standards? Perkins Coie. Viewed online 4/27/2018 at http://www.perkinscoie.com/is-your-organization-prepared-for-compliance-with-nerc-reliability-standards-02-18-2010.

Loy, Brendan. 2003. The Empire State Building in the Dark During the Great Northeast Blackout of 2003, IMG 6514. Source: Flickr Creative Commons. https://www.flickr.com/photos/brendanloy/2669855698.

North American Electric Reliability Corporation. About NERC. http://www.nerc.com/AboutNERC/Pages/default.aspx.

North American Electrical Reliability Corporation. 2017. 2017 Long-Term Reliability Assessment. Downloaded 4/27/2018 from https://www.nerc.com/pa/RAPA/ra/Pages/default.aspx.

Nersesian, Roy. 2007. Energy for the 21st Century: A Comprehensive Guide to Conventional and Alternative Sources. Armonik, NY: M.E. Sharpe.

Wikipedia. Adams Power Plant Transformer House. http://en.wikipedia.org/wiki/Adams_Power_Plant_Transformer_House.

Wikipedia. Tennessee Valley Authority. http://en.wikipedia.org/wiki/Tennessee_Valley_Authority.