Drinking water regulations - American Water Works Association

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treatment technologies for compliance, and these technologies are generally more ... and 1996. The evolution of the USEPA's regulatory program has been pre-.
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BY STEPHEN J. REILING, J. ALAN ROBERSON, AND JOHN E. CROMWELL III

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Drinking water regulations: Estimated cumulative energy use and costs

THIS ARTICLE EXAMINES

T H E C U M U L AT I V E E N E R G Y

U S E A N D R E S U LT I N G C O S T S

F R O M T H E 1 8 N AT I O N A L PRIMARY DRINKING

W AT E R R E G U L AT I O N S .

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etween 1975 and 2006, the US Environmental Protection Agency (USEPA) published 18 National Primary Drinking Water Regulations (NPDWRs). The more recent regulations use more advanced treatment technologies for compliance, and these technologies are generally more energy-intensive than conventional treatment processes. USEPA is required to conduct a statutory and Executive Order (EO) review for each of its regulations that covers a broad range of issues, such as the Paperwork Reduction Act, the Regulatory Flexibility Act, the Unfunded Mandates Review Act, and others. A relatively recent component of this review is defined in EO 13211, “Actions Concerning Regulations That Significantly Affect Energy Supply, Distribution, or Use,” which requires federal agencies to conduct an analysis of energy and use this to develop a Statement of Energy Effects for any proposed rulemaking. The cumulative energy use from the 18 NPDWRs is 1.8 billion kW·h/year, and the cumulative energy cost is $187 million/year in 2008 dollars.

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A HISTORICAL OVERVIEW OF THE REGULATIONS The initial Safe Drinking Water Act (SDWA) was signed into law on Dec. 16, 1974 (PL 93-253). The 1974 SDWA gave the USEPA the authority to set NPDWRs and to require the states to adopt their own regulations—at least as strict as the federal regulations—in order to maintain “primacy” over state-level drinking water programs. The 1974 SDWA was amended in 1986 and 1996. The evolution of the USEPA’s regulatory program has been previously summarized (Roberson, 2006).

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Between 1975 and 2006, USEPA published 18 national NPDWRs (Table 1). These regulations can be split into two categories: • pre-1996 SDWA Amendments (the “new” regulations), and • post-1996 SDWA Amendments (the “old” regulations). A previous analysis showed that the regulations promulgated after 1996 were more complex than pre-1996 regulations for a variety of reasons, including more complex compliance determinations and more advanced treatment technologies necessary for compliance (Roberson, 2003). The SDWA frames the USEPA’s regulatory program using specific statutory language on the selection of contaminants for regulation (or not), determining what levels of the contaminants are “safe,” identifying effective treatment technologies, and conducting the appropriate benefit-cost analyses (BCAs). Sections 1412(b)(3) and 1412(b)(5) of the 1996 SDWA Amendments significantly increased the BCA requirements, with specific requirements for health risk reduction and cost

analysis and additional required documentation for post-1996 regulations. The 1996 SDWA Amendments also listed several new factors, such as sensitive populations, that are now considered in the development of NPDWRs. USEPA is required to conduct a statutory and EO review for each of its regulations. A relatively recent component of this review is defined in EO 13211, “Actions Concerning Regulations That Significantly Affect Energy Supply, Distribution, or Use” (Presidential Documents, 2001). This EO requires federal agencies to conduct an analysis of energy use to develop a Statement of Energy Effects for any proposed rulemaking. USEPA has conducted the energy analyses required by EO 13211 for the four most recent drinking water regulations: • the Long Term 1 Enhanced Surface Water Treatment Rule (LT1ESWTR; USEPA, 2002), • the Stage 2 Disinfectants and Disinfection Byproducts Rule (D/ DBPR; USEPA, 2006a),

• the Long Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR; USEPA, 2006b), and • the Ground Water Rule (GWR; USEPA, 2006c). Each rule was determined not to be a “significant energy action” as defined in EO 13211, because none was likely to have a significant adverse effect on the supply, distribution, or use of the total energy produced. The LT1ESWTR was the first regulation promulgated after the introduction of EO 13211. Given the limited period between the release of the EO and the promulgation of this rule, only a cursory energy evaluation was performed, from which USEPA determined that the energy use for the LT1ESWTR would be minimal. Using the methods presented in this article, the evaluation was proven to be correct— the LT1ESWTR was not a “significant energy action.” Table 2 summarizes the USEPA-calculated energy use for the LT1ESWTR, the Stage 2 D/DBPR, the LT2EWTR, and the GWR.

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specific conditions, to comply with the post-1996 regulations. These more advanced treatment technologies are generally more energyintensive than conventional treatment processes. For example, at $0.0663/kW·h, the annual power

ADVANCED TECHNOLOGIES ARE GENERALLY MORE ENERGY INTENSIVE The objective of this article is to determine the cumulative energy use and the resulting costs from the treatment technologies used for

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s population increases in the Sunbelt states, the combined demands for energy and water will continue to increase. cost for a 10-mgd water treatment plant with conventional treatment would be approximately $51,000 as opposed to $59,000 when adding U V disinfection, $131,000 when adding 1.0-log ozone disinfection, and $137,000 when adding low-pressure MF/ UF to conventional treatment (Raucher et al, 2008). Ozone treatment, through the generation of ozone on site, can

compliance with the 18 NPDWRs. In addition, this article provides some basic analysis of the resulting costs. The use of more advanced treatment technologies such as ion exchange, low pressure microfiltration/ultrafiltration (MF/UF) membranes, ozone, ultraviolet light (UV), and others, is increasing as utilities select the appropriate treatment technology, based on site-

TABLE 1

National Primary Drinking Water Regulations Rule

Year Promulgated

Federal Register Citation

NIPDWR

1975

40:248:59566

TTHM

1979

44:231:68624

Fluoride

1986

51:63:11396

VOCs (phase 1)

1987

52:130:25690

SWTR

1989

54:124:27486

TCR

1989

54:124:27544

SOCs and IOCs (phase 2)

1991

56:20:3526

LCR

1991

56:110:26460

SOCs and IOCs (phase 5)

1992

57:138:31776

Stage 1 D/DBPR

1998

63:241:69389

IESWTR

1998

63:241:69477

Radionuclides

2000

65:236:76707

Arsenic

2001

66:14:6975

FBRR

2001

66:111:31085 67:91:1844

LT1ESWTR

2002

D/DBPR

2006

71:2:387

LT2ESWTR

2006

71:3:653

GWR

2006

71:216:65573

D/DBPR—Disinfectants/Disinfection Byproducts Rule, FBRR—Filter Backwash Recycling Rule, GWR— Ground Water Rule, IESWTR—Interim Enhanced Surface Water Treatment Rule, IOCs—inorganic chemicals, LCR—Lead and Copper Rule, LT1ESWTR—Long Term 1 Enhanced Surface Water Treatment Rule, LT2ESWTR—Long Term 2 Enhanced Surface Water Treatment Rule, NIPDRW—National Interim Primary Drinking Water Regulations, SOCs—Synthetic Organic Chemicals, SWTR—Surface Water Treatment Rule, TCR—Total Coliform Rule, TTHM—Total Trihalomethanes, VOCs—volatile organic chemicals

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account for about 10% of a utility’s energy use (AwwaRF, 2005). As more and more utilities install these more advanced treatment technologies to comply with the new regulations, the cumulative increase in energy use could be significant. Energy impacts in the future could be significant as well, as future regulations may be targeting hard-totreat contaminants such as N-nitro sodimethylamine (NDMA). In other words, the added energy re quired to remove hard-to-treat contaminants is not necessarily a matter of entropy. As stated previously, EO 13211 requires an analysis of three components: energy supply, distribution, and use. The focus of this article is on energy use (and the resultant energy costs) from the compliance technologies needed to meet the regulations and assumes that the impacts on supply and distribution will be minimal, as discussed subsequently. Energy supply. With regard to energy supply, USEPA does not regulate power generation. The Federal Energy Regulatory Commission (FERC) regulates power generation and transmission at the federal level. In addition, the vast majority of private and public water systems (PWSs) under regulation by USEPA’s SDWA authority generally do not generate power for export to the power grid, although many have standby generators to increase system reliability. Some systems with reservoirs may generate hydroelectric power, and some systems have on-site electrical-generating capability for “peak shaving.” Conversely, the power generation utilities that are PWS customers are unlikely to be significantly affected by the drinking water regulations. In summary, the regulations do not regulate the supply of energy, do not generally regulate the utilities that supply energy, and are unlikely to significantly affect the customer base of energy suppliers. The quantity of water used in power generation is significant, and

the linkage between energy and water is getting more media attention (Webber, 2008). The Department of Energy (DOE) Sandia National Laboratories recently completed a report on the “energy–water nexus” that concluded that U.S. citizens may indirectly depend as much on water when turning on the lights as when taking a shower or watering the lawn (USDOE, 2006). The US Geologic Survey (USGS) estimates that 48% of the water withdrawn in the United States is used for thermoelectric power generation versus 12% for public and private water supplies (USGS, 2004). As population increases in the Sunbelt states, the combined demands for energy and water will continue to increase. Energy distribution. The second consideration is whether the drinking water regulations would ad versely affect the distribution of energy. As stated earlier, FERC, not USEPA, regulates energy distribution at the federal level. PWSs subject to USE PA regulations clearly already have electrical service. Additionally, the drinking water regulations are projected to cause a negligible increase in peak electricity demand at PWSs. Therefore, USEPA assumes that the existing electrical supply connections are adequate and that the drinking water regulations will have no discernable adverse effect on energy distribution. Energy use. Total energy used by water and wastewater utilities is not insignificant. In the United States, approximately 4% of the national energy use is for drinking water treatment and distribution and for wastewater collection and treatment (Raucher, 2008). In areas of the country such as California, where moving water across large distances is common, water related energy use increases to 19% of the total electricity used in that state (CEC, 2005). The energy costs of drinking water regulations are typically within the treatment plant. Energy

topography between the source water and the water treatment plant, and the topography in the distribution system. Utilities with flat topography in their service area in Florida and the Gulf Coast have much less pumping and energy use than comparable systems with substantial topography and/or pumping distance. For example, based on the Water:\Stats 1996 Survey, the City of Chesapeake, Va., with relatively flat topography, had an energy cost of $327,900 for its supply, pumping, and transmission. This compares with an energy cost of $1,370,000 for the San Bernandino (Calif.) Water Department (with a compa-

use is significant for water supply and distribution systems, particularly for the latter. On average, 85% of the energy used is for pumping in the distribution system, 9% is used for pumping raw water to the treatment plant, and the treatment processes use 6% (AwwaRF, 2005). Therefore, optimization of distribution system operations for efficient energy management is critical, and the Water Research Foundation, along with other research organizations, has several projects addressing that issue. Energy use can vary substantially from utility to utility, primarily depending on the distance and

TABLE 2

Executive Order 13211 energy cost calculations

Rule

Total Annual Energy Required* kW·h/year

NIPDWR‡ TTHMs Fluoride

Total Annual Energy Cost 2008 dollars†

NA

NA

40,000,000

$4,848,485

7,035,000

$1,032,869

VOCs (phase 1)

34,861,000

$4,540,354

SWTR

171,227,000

$19,594,445

TCR §

NA

NA

243,421,000

$29,151,628

SOCs and IOCs (phase 2) LCR § SOCs and IOCs (phase 5)

NA

NA

90,436,000

$9,671,431

Stage 1 DBPR

114,494,000

$10,415,442

IESWTR

146,218,000

$13,301,353

Radionuclides

194,456,000

$17,487,034

Arsenic

266,706,000

$25,674,855

FBRR

31,226,000

$2,908,261

LT1ESWTR

32,441,305

$3,084,426

Stage 2 D/DBPR

116,302,140

$12,376,050

LT2ESWTR

165,551,898

$17,616,892

GWR Total

4,520,555 1,658,895,898

$481,093 $172,184,617

D/DBPR—Disinfectants/Disinfection Byproducts Rule, FBRR—Filter Backwash Recycling Rule, GWR— Ground Water Rule, IESWTR—Interim Enhanced Surface Water Treatment Rule, IOCs—inorganic chemicals, LCR—Lead and Copper Rule, LT1ESWTR—Long Term 1 Enhanced Surface Water Treatment Rule, LT2ESWTR—Long Term 2 Enhanced Surface Water Treatment Rule, NA—not applicable, NIPDRW— National Interim Primary Drinking Water Regulations, SOCs—Synthetic Organic Chemicals, SWTR— Surface Water Treatment Rule, TCR—Total Coliform Rule, TTHM—Total Trihalomethanes, USEPA—US Environmental Protection Agency, VOCs—volatile organic chemicals *Total annual energy required for the TTHMs, LT1ESWTR, Stage 2 D/DBPR, LT2ESWTR, and GWR has been calculated by USEPA and is reported by the authors. All other values have been calculated by the authors. †Total Annual Energy Cost was determined by multiplying Total Annual Energy Required by the retail price of electricity for the year the economic analysis was published (EIA, 2007). This cost was then multiplied by the CPI index factor (BLS, 2008) for that year to convert to 2008 dollars. Adjusting energy costs to 2008 dollars in this manner results in a wider range of unit energy costs ($0.075 to $0.15/kW·h) than expected, because USEPA has historically used unit energy costs between $0.076 and $0.086/kW·h. However, this method was used so that energy costs as a percentage of total compliance costs could be calculated, as shown in Table 5. ‡Baseline for study §No new treatment technologies being installed that would require additional energy

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rable population served), an area with much hillier topography. Water supply pu mping and energy use by utilities other than those in regions with great variations in topography can be substantial. For example, to supply Metropolitan Water District of Southern California (MWDSC) and other utilities in southern California, State Water Project (SW P) water is pumped multiple times at a substantial cost to the ultimate terminus at Lake Perris. The cost of power is 32% of the SWP operations and maintenance (O&M) costs, and in 1996, the SWP power cost was $192 million (State of California, 2008). On the other hand, other utilities in California such as the San Francisco Public Utilities Department (SFPUD) and East Bay Municipal Utility District (EBMUD) are able to take

TABLE 3

projects. Some electric utilities have been providing energy optimization assistance to water and wastewater utilities. The USEPA has also ad dressed this issue in a recently released energy management guidebook (USEPA, 2008). The leading water utilities are fast advancing the frontiers of energy optimization through the use of complex pumping and storage optimization algorithms linked to supervisory control and data acquisition (SCADA) systems and complex electric tariff structures and conservation incentive programs. In water stressed regions, an even more intricate optimization challenge must be solved when choosing whether to invest energy in moving and storing water from various sources within a water resources portfolio versus producing new water

advantage of the natural elevation and use gravity for a substantial portion, or in some cases all, of their water supply. Other utilities on the East Coast, such as the Massachusetts Water Resources Authority (MWRA) and the New York City Department of Environmental Protection (NYCDEP), are also able to use gravity to their advantage. Utilities are under constant pressure to optimize their operations, including energy use. Energy costs can be a substantial portion of the overall O&M costs at an individual utility. The cost of energy is typically one of the largest components of a utility’s operating costs, ac counting for as much as 35% (AwwaRF, 2005). The Water Re search Foundation has completed several projects on energy optimization, and has several more ongoing

Effects of regulations on national energy usage

Rule

Year

Total Annual Energy Required mil kW·h/year

National Energy Usage bil kW·h/year*

Increase in Annual Average Energy Use %

NIPDWR†

1975

NA

NA

NA

TTHM

1979

40.0

2,290 (1989)

0.002

Fluoride

1986

7.0

2,473 (1985)

0.000

VOCs (phase 1)

1987

34.9

2,473 (1985)

0.001

SWTR

1989

171.2

3,038 (1990)

0.006

TCR ‡

1989

NA

NA

NA

SOCs and IOCs (phase 2)

1991

243.4

3,038 (1990)

0.008

LCR ‡

1991

NA

NA

NA

SOCs and IOCs (phase 5)

1992

90.4

3,038 (1990)

0.003

Stage 1 D/DBPR

1998

114.5

3,620

0.003

IESWTR

1998

146,2

3,620

0.004

Radionuclides

2000

194.5

3,695 (1999)

0.005

Arsenic

2001

266.7

3,695 (1999)

0.007

FBRR

2001

31.2

3,802 (2000)

0.001

LT1ESWTR

2002

32.4

3,695 (1999)

0.001

Stage 2 D/DBPR

2006

116.3

3,848§

0.003

LT2ESWTR

2006

165.6

3,848§

0.004

GWR

2006

4.5

3,848§

0.000

D/DBPR—Disinfectants/Disinfection Byproducts Rule, FBRR—Filter Backwash Recycling Rule, GWR—Ground Water Rule, IESWTR—Interim Enhanced Surface Water Treatment Rule, IOCs—inorganic chemicals, LCR—Lead and Copper Rule, LT1ESWTR—Long Term 1 Enhanced Surface Water Treatment Rule, LT2ESWTR—Long Term 2 Enhanced Surface Water Treatment Rule, NA—not applicable, NIPDWR—National Interim Primary Drinking Water Regulations, SOCs—Synthetic Organic Chemicals, SWTR—Surface Water Treatment Rule, TCR—Total Coliform Rule, TTHM—Total Trihalomethanes, USEPA—US Environmental Protection Agency, VOCs— volatile organic chemicals *Source: EIA, 2009. Figures are not available for all years, in which case usage information for the nearest record year was used. † Baseline for study ‡ No new treatment technologies being installed that would require additional energy §The USEPA is aware that the Department of Energy has updated its estimate of total electricity produced in 2003 from 3,848 million to 3,833 million. However, USEPA continues to use the 3,848 million estimate to maintain consistency with related electricity estimates used in the economic analysis and the technologies and cost document for the LT2ESWTR.

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TABLE 4

Determination of energy use for rapid mix improvements under the IESWTR

Community Water System Size population served

Design Flow mgd*

Average Daily Flow Total per Plant Number of mgd* Systems†

Number of Systems Expected to Modify Treatment†

Percentage of Systems Number Selecting of Systems Technology Selecting % Technology‡

Annual Energy Cost per Plant $/plant/ year§

Total Energy Usage Annual for Plants Energy Selecting Requirement Technology kW·h/ kW·h/ plant/year** plant/year

< 10,000

NA

NA

4,880

NA

NA

NA

NA

NA

10,001–25,000

4.8

2.1

594

303

15

45

4,081

68,017

3,091,374

25,001–50,000

11

5

316

161

15

24

9,447

157,451

3,802,448

50,001–75,000

18

8.8

124

63

10

6

16,478

274,641

1,730,238

75,001–100,000

26

13

52

27

5

1

24,250

404,166

545,625

100,001–500,000

51

27

259

122

1

1

50,155

835,918

1,019,820

500,001–1 million

210

120

26

11

1

0

222,239

3,703,981

407,438

> 1 million

518

348

10

4

1

0

644,122

10,735,361

6,261

691

Totals

79

NA

429,414 11,026,356

*Source: Appendix B-1. USEPA, 1998a. †Source: Exhibit ES.4. USEPA, 1998b. ‡Number of systems determined from percentages listed in Appendix A-1. USEPA, 1998a. §Annual energy cost per plant is taken from Appendix B. USEPA, 2000. **Electricity cost is $0.06/kW·h, as presented in Appendix B. USEPA, 2000. ††Number of systems determined from percentages listed in Appendix A-1. USEPA, 1998a. IESWTR—Interim Enhanced Surface Water Treatment Rule, LT1FBR—Long Term 1 Enhanced Surface Water Treatment and Filter Backwash Rule, NA—not applicable, RIA—regulatory impact analysis, T&C—technology and cost, USEPA—US Environmental Protection Agency Performance limitations identified at omposite Correction Program (CPP) plants was 14%.†† CPP is a USEPA program designed to look at problem plants and try to fix them. The adjusted total energy usage for plants selecting technology was 1,543,690 kW·h/year.

from saline or re claimed sources using energy-intensive membrane processes. The advent of more energy-intensive treatment processes driven by SDWA regulations adds another layer to this already complex optimization challenge. The growing national interest in reducing greenhouse gas emissions and minimizing the carbon footprint of utility operations adds yet another strong driver for energy optimization. However, the most recent Water Research Foundation research on energy management (Raucher, 2008) has highlighted the fact that overly aggressive energy-management initiatives may result in unintended side effects on water system reliability, especially water quality reliability. The demand for complex optimization of energy used in transmission and distribution—potentially involving new patterns of water flow and real-time changes in flow patterns— comes at a time when SDWA compliance determinations are becoming much more focused on distributed water quality. In addition, treatment

technologies such as UV are not just energy-intensive, but demanding of a high degree of power quality—interruptible power service could cause the UV bulbs to “blink” just enough to adversely affect inactivation. Equipment protection measures, such as uninterrupted power supply (UPS) and fly-wheel technologies, should be used to protect against power interruptions and “brownouts.” Finally, the electric tariff structures create a significant class of operating reliability challenges for water utilities. Consider the operator on the night shift who senses the need to backwash a filter but is also aware that the electric meter is right at the point where it would trip the plant into the next rate category for the ensuing time period (costing many thousands of dollars) unless he can wait until after midnight.

ANALYSIS IS FOCUSED ON CWSS’ ENERGY USE This analysis focuses only on the energy used by community water systems (CWSs) because these systems

are generally the ones covered by the NPDWRs and are the ones installing the compliance technologies with their associated energy use and cost. This analysis does not include nontransient–noncommunity water systems (NTNCWSs) or transient, noncommunity water systems (TNCWs). NTNCWs and TNCWSs are typically smaller systems that have limited treatment, and therefore, combined with the small number of regulations (such as the Total Coliform Rule [TCR]) that apply to these systems, their energy use compared with CWSs would be minimal.

ENERGY COSTS FOR REGULATIONS AFTER EO 13211 As discussed previously, EO 13211 was applicable to only the four most recent drinking water regulations. The economic analysis (EA) for one of these regulations— the LT2ESWTR—contains a de tailed example of the methodology used to determine the effect of the regulation on energy use (USEPA, 2005a). First, the energy used by the

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TABLE 5

Total increased annual national energy usage attributable to IESWTR

Technology

Plants Selecting Technology—number

Total Annual Energy Required kW·h/year

Rapid mix improvements

79

Flocculation improvements

29

1,086,572

Filtration improvements

186

141,627,419

1,543,690

Chemical addition

159

640,000

Coagulation improvements

104

300,000

Settling improvements Total

29

1,020,000

585

146,217,681

IESWTR—Interim Enhanced Surface Water Treatment Rule

technologies expected to be installed as a result of the regulation is estimated. The different compliance treatment technologies are typically provided in compliance forecasts and are spread across the different system sizes and flow ranges used by USEPA in these forecasts. For example, small systems might be predicted to use less-complex compliance treatment technologies than larger systems. The energy use per

comparing the estimated energy use derived previously with the national production figures for electricity, 2 resulting in the total increase in energy usage by water systems as a result of the rule for the given year. Table 3 provides the effects of the regulations on national energy use for each rule. Although it was not required for this study, the energy suppliers’ peakseason generating capacity reserve

W

ith the rising cost of fuel and electricity, increased costs get passed on to the consumers through increased water rates.

plant is determined by dividing the total energy cost per plant for a range of f lows by an average national cost of electricity.1 The energy use per plant for each flow range and technology is then multiplied by the number of plants predicted to install each technology in a given flow range. The energy requirements for each flow range are added to produce a national total energy use. Second, for EO 13211, an analysis must be conducted to determine whether the additional energy re quired for utilities to comply with the rule would have a significant adverse effect on the use of energy at the national level. This is done by 48

to water flow through the plant and that peak flow can be as high as twice the average daily flow during the summer months, the average power demand is then doubled for the peak-flow analysis.

can be compared with an estimate of peak incremental power demand by water utilities. This comparison will determine whether utilities’ demand might affect the capacity margins of the suppliers, because both energy use and water use are highest in the summer months. This capacity-margin analysis is conducted by dividing the total energy requirement, which was previously determined, by 8,760 hours/year (assuming constant operation of water treatment plants throughout the year) to obtain an average power demand for the modeled Information Collection Rule occurrence distribution for the LT2ESWSTR. Assuming that power demand is proportional

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ENERGY COSTS FOR REGULATIONS PRIOR TO EO 13211 For the last three regulations— D/DBPR, LT2ESWTR, and GWR— the EAs provide detailed examples on how energy costs were determined. In addition, the technology and cost (T&C) document for each of these rules isolates power costs in tables or by providing formulas to calculate the power costs. This is not typically the case for the rest of the regulations. For the majority of the regulations prior to EO 13211, the EA and T&C documents do not explicitly indicate power costs. Instead, electricity and power costs are included in overall O&M costs. Therefore, in order to determine energy requirements for each regulation, a technology-based approach was used with the aid of compliance forecasts provided in the supporting documents. The first step in this approach was to determine energy costs for the technologies used in the DPBR, LT2ESWTR, and GWR rules be cause the methodology is provided in the EA and T&C document for each of these rules. For any prior regulation using the same or a similar technology, a similar method of determining energy costs was used. A spreadsheet was built for each regulation to determine the number of systems in each size category that would install a specific compliance technology and to determine the resulting energy usage costs. For example, M F/ U F membranes are one of the technologies forecast in the Stage 1 D/DBPR (USEPA, 1998a). Section 4.4.5.2 of the LT2ESWTR T&C document (USEPA, 2005b) provides the following equations for annual power costs for membrane technology:

TABLE 6

Inventory of supporting documents for each rule

Year

Federal Register Citation

Economic Analysis/ Regulatory Impact Analysis

Technology and Cost

NIPDWR*

1975

40:248:59566

NA

NA

TTHM

1979

44:231:68624



Fluoride

1986

51:63:11396



Volatile SOCs (Phase 1)

1987

52:130:25690

TCR

1989

54:124:27544



SWTR

1989

54:124:27486



LCR

1991

56:110:26460



SOCs and IOCs (Phase 2)

1991

56:20:3526

Rule



SOCs and IOCs (Phase 5)

1992

57:138:31776

Stage 1 D/DBPR

1998

63:241:69390



IESWTR

1998

63:241:69478



Radionuclides

2000

65:236:76708





Arsenic

2001

66:14:6976





FBRR

2001

66:111:31086



✓ (proposed)

LT1ESWTR

2002

67:9:1812



✓ (proposed)

Stage 2 D/DBPR

2006

71:2:388



LT2ESWTR

2006

71:3:654





GWR

2006

71:216:65574









D/DBPR—Disinfectants/Disinfection Byproducts Rule, FBRR—Filter Backwash Recycling Rule, GWR—Ground Water Rule, IESWTR—Interim Enhanced Surface Water Treatment Rule, IOCs—inorganic chemicals, LCR—Lead and Copper Rule, LT1ESWTR—Long Term 1 Enhanced Surface Water Treatment Rule, LT2ESWTR—Long Term 2 Enhanced Surface Water Treatment Rule, NA—not applicable, NIPDWR—National Interim Primary Drinking Water Regulations, SOCs—Synthetic Organic Chemicals, SWTR—Surface Water Treatment Rule, TCR—Total Coliform Rule, TTHM—Total Trihalomethanes, VOCs—volatile organic chemicals *Baseline for study

For average flow < 0.36 mgd: power ($/year) = 16,561 × (average flow)1.0113 For average flow 0.36–4.5 mgd: power ($/year) = (5096.5 × average flow) + 4058.8 For average flow > 4.5 mgd: power ($/year) = (5356.9 × average flow) + 2666.3 These equations, along with the compliance forecast provided in Appendix A-1 of the Stage 1 D/DBPR Regulatory Impact Analysis (RIA; USEPA, 1998b), were used to de termine the annual power costs across the CWS system sizes for the D/DBPR. For technologies for which equations were not available, a combination of best professional judgment (BPJ) and approximations from industry standards was used. For example, power costs are not provided in the supporting documents

for the Interim Enhanced Surface Water Treatment Rule (IESWTR). However, compliance treatment technologies and the percentage of power used in each system-size category are given in Appendix A-1 of the IESWTR RIA (USEPA, 1998c). BPJ was used to determine which technologies from the IESW TR compliance forecast resulted in increased energy use. For example, coagulant, rapid mix, flocculation, and settling improvements, along with administrative culture, laboratory, and process testing improvements, were assumed to not increase energy use. Improving backwashing—through increased velocity and installing additional chemical feeds—was assumed to require a new pump or increased pumping capacit y that would result in increased energy use. With the use of a linear trend function and annual energy cost values—on an average flow (million gallons per day) basis—for similar technologies

from the Long Term 1 Enhanced Surface Water Treatment and Filter Backwash Rule (LT1FBR) T&C document (USEPA, 2000), cost values for each CWS system size were generated. Table 4 shows how energy use for improvements to rapid mix technology was determined for the IESWTR, and Table 5 provides the total annual energy required for all technology improvements under the IESWTR.

THE BIG PICTURE: ENERGY NEEDED TO COMPLY WITH NPDWRS IS RELATIVELY SMALL T he estimated total annual energy use for all 18 NPDWRs is shown in Table 2. The cumulative energy use for the treatment technologies used for compliance with these regulations is 1.8 billion kW·h/ year, and the energy required for each regulation varies from 0.04 million to 310 million kW·h/year. The cumulative energy cost is $187 million/year in 2008 dollars.

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TABLE 7

Comparison of annual energy and compliance costs

Rule

Total Annual Energy Cost mil $/year in 2008 dollars

Annual Compliance Cost mil $/year in 2008 dollars

Energy Cost as a Percentage of Compliance Cost—%

NIPWDR*

NA

NA

NA

TTHMs

4.8

47.6

10.2

Fluoride

1.0

6.6

15.6

VOCs (phase 1)

4.5

42.9

10.6

SWTR

19.6

919.0

2.1

TCR†

NA

242.2

NA 12.8

SOCs and IOCs (phase 2)

29.2

227.1

LCR†

NA

1,030.5

NA

SOCs and IOCs (phase 5)

9.7

72.1

13.4

Stage 1 D/DBPR

10.4

845.6

1.2

IESWTR

13.3

387.2

3.4

Radionuclides

17.5

107.0

16.3

Arsenic

25.7

238.2

10.8

FBRR

2.9

7.4

39.2

LT1ESWTR

3.1

52.2

5.9

Stage 2 D/DBPR

12.4

94.2

13.1

LT2ESWTR

17.6

132.4

13.3

GWR

0.5

73.9

0.7

Total

172.2

4,526.1

NA

D/DBPR—Disinfectants/Disinfection Byproducts Rule, FBRR—Filter Backwash Recycling Rule, GWR—Ground Water Rule, IESWTR—Interim Enhanced Surface Water Treatment Rule, IOCs—inorganic chemicals, LCR—Lead and Copper Rule, LT1ESWTR—Long Term 1 Enhanced Surface Water Treatment Rule, LT2ESWTR—Long Term 2 Enhanced Surface Water Treatment Rule, NA—not applicable, NIPDWR—National Interim Primary Drinking Water Regulations, SOCs—Synthetic Organic Chemicals, SWTR—Surface Water Treatment Rule, TCR—Total Coliform Rule, TTHM—Total Trihalomethanes, VOCs—volatile organic chemicals *Baseline for study †No new treatment technologies being installed that would require additional energy

On a national basis, the energy used to comply with the NPDWRs is a relatively insignificant portion of the national energy use, ranging from 0.001 to 0.009% (Table 3). This is not surprising because, as previously discussed, the vast majority of energy used in water treatment and distribution is for pumping raw water and for pumping in the distribution system.

AVAILABILITY OF EAS AND T&C DOCUMENTS Many of the EAs and T&C docu ment s were acqu i red on l i ne through Regulations.gov, a source for all regulations issued by US government agencies. 3 For some of the older rules, however, the supporting documents could not be located online. In these cases, specific re quests for the documentation were submitted to the USEPA Water Docket.4 For most of the regula50

tions, the documentation could be found, but in some instances, EAs and/or T&Cs could not be acquired by either method. The missing documentation was primarily for the old regulations, i.e., regulations finalized prior to the 1996 SDWA Amendments. For these old regulations, BPJ was used to approximate which compliance technologies would be used for each category of population served. Table 6 details which supporting documents could be located for each of the 18 drinking water regulations.

CUMULATIVE ENERGY COSTS COULD BE SIGNIFICANT The energy cost resulting from the 18 NPDWRs is not significant compared with the national energy usage. However, the cumulative energy cost could be significant. T he total an nual costs — both energ y co st s a nd compl ia nc e

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costs—in 2008 dollars for all 18 drinking water regulations are shown in Table 7. The energy costs range from approximately $3 million to $29 million, with a cumulative energy cost of $187 million/ year. The compliance costs range from approximately $6 million to $1 billion, with a cumulative cost of compliance from the 18 national drinking water regulations of $4.5 billion/year. Both of these costs are substantial. The cumulative compliance cost was determined by adjusting the national compliance cost from USEPA’s RIAs and EAs to 2008 dollars using the Consumer Price Index (CPI). Additionally, at an individual utility, more advanced compliance treatment technologies can substantially increase O&M costs. The more complex regulations are driving utilities to more advanced treatment technologies such as U V,

In their efforts to remain in compliance with the US Environmental Protection Agency’s 18 National Primary Drinking Water Regulations, utilities more and more are turning toward advanced technologies that consume increasing amounts of energy.

ozone, and membranes (Roberson, 2003). In Table 7, the energy cost as a percentage of compliance cost did not show an increasing trend with the newer regulations as one might expect. This is likely because of both annual capital costs and annual O&M costs typically being combined into the compliance cost. A recent report on the national cost implications of potential perchlorate regulations found annual O&M costs to be greater than the annual capitals costs (MPI, 2008). More work is needed in developing a better understanding of the relationships between the different components (chemicals, labor, electricity) of the predicted O&M costs in the various RIAs and EAs. Conducting a detailed analysis of the breakdown among the different components was beyond the scope of this research. A detailed analysis of the increased energy use and increased O&M costs for an individual utility installing a specific ad vanced compliance treatment technology was also beyond the scope of this research. The use of more advanced treatment technologies that require more

energy is going to continue to grow, whether or not the technologies are being installed for compliance with national drinking water regulations. A recent report (Raucher, 2008) found that “The number of MF/UF plants in the U[nited] S[tates] has increased dramatically in the past 16 years. . . . Since the promulgation of the IESWTR in 1998, the number of MF/UF plants in the U[nited] S[tates] has increased more than fourfold” (Raucher, 2008). As stated previously, costs for both energy use and compliance for each of the 18 regulations are included in Table 7. In addition, energy costs as a percentage of compliance costs are provided. Drawing conclusions about the relationship between energy costs and compliance costs is difficult without a detailed statistical analysis; however, energy costs in general account for approximately 10 to 20% of the costs of compliance for the drinking water regulations. Factors such as the number of treatment trains and/or the number of treatment plants required to install technologies—including the specific types of treatment technolo-

gies—as a result of drinking water regulations will affect the ratio between national energy and compliance costs. At the individual treatment plant level, economies of scale for specific treatment technologies will vary based on several factors such as design flow, whether the installation is greenfield or retrofit, and raw water quality. Other issues are affecting energy use by utilities. For example, for new water sources utilities are going to sources of lower quality, because the highest-quality source water is already being used. Therefore, more advanced treatment, with inherently higher energy use, is needed to treat the lower-quality water. Desalination of both brackish water and seawater is increasingly being used to provide a new source of drinking water. The global market for seawater and brackish water desalination plants increased from $1.7 billion in 2005 to $1.9 billion in 2007 and is predicted to increase to $3.6 billion in 2012 (BCC Research, 2008). Utilities are also going farther for new water sources, which re quires more pumping and energy.

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For example, Southern Nevada Water Authority (SNWA) is planning a significant groundwater development project in Clark, Lincoln, and White Pine counties to provide a significant portion of its required new water supply to meet future demand (SNWA, 2008). The facilities being planned for this project include 285 mi of pipeline, three pumping stations, and a new 150-mgd water treatment plant that will likely have advanced treatment processes because of the lower quality of the groundwater. Needless to say, the treatment plant and pumping stations will increase the SNWA energy use. SNWA is not unique to the Sunbelt in having to look farther away for new water sources and having to plan for advanced treatment technologies because these new sources are typically of lower quality.

RECOMMENDATIONS FOR GOING FORWARD More research is needed on linkages between increased energy use and increased O&M costs for advanced treatment technologies, both from a national perspective and from an individual utility perspective. The increased energy use is important as costs continue to in crease, and more research is needed on the percentage of energy costs in relation to the total O&M costs for specific advanced treatment technologies. Once an ad vanced treatment technology is installed, it is rarely taken offline or retired. Utilities need a better understanding of how treatment selection decisions will affect future O&M costs. Additional research is needed to better understand the uncertainties surrounding energy costs and how those uncertainties can affect future energy and O&M costs. For example, the increase in gasoline prices over the past three years has caused increased construction costs and O&M budget shortfalls for many utilities. Models need to 52

be improved to take into account a wider variability in potential future increases in energy usage and costs. Finally, more research is needed on providing tools for utilities to translate energy use (and the resulting costs) into an inventory of greenhouse gas (GHG) emissions and/or a carbon footprint, from both a direct and indirect perspective. Training will be needed to assist utilities in understanding these tools. The Water Research Foundation is collaborating with the California Urban Water Agencies (CUWA) for the development of guidance on creation of an inventory of GHG emissions and management strategies for water utilities. The California Climate Action Registry (CCAR) was formed in 2001 as a voluntary GHG registry, and several California water utilities are members (CCAR, 2008). As previously discussed, the vast majority of energy used by a water utility is for distribution system pumping, but significant amounts of fuel are used by the typical utility fleet of cars and trucks, as well as construction equipment (backhoes, excavators, bulldozers, graders) for O&M activities. In addition, the heating, cooling, and lighting of water treatment facilities, office buildings, and maintenance facilities result in a similar energy demand and carbon footprint.

CONCLUSIONS Utilities should be concerned about using more energy, whether or not the increased use is for compliance with a drinking water regulation. With the rising cost of fuel and electricity, increased costs get passed on to the consumers through increased water rates. In addition, national attention is being placed on energy efficiency and independence. National energy policy is increasingly moving toward alternative energy and “green” technologies, and the focus on the use of these technologies by water and

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wastewater utilities will only increase in the future. Finally, energy demand and the use of the electricity transmission systems in the United States are increasing at a rate greater than upgrades to the current system or construction of new transmission facilities (EIA, 2003). In California, where generation capacity shortages in the summer of 2000 forced temporary power outages in the northern part of the state, generation capability decreased 2% from 1990 through 1999, whereas retail sales increased by 11% (EIA, 2005). As previously discussed, approximately 4% of the national electricity use is for water and wastewater treatment. However, in California the energy needed to pump and treat water increases to 19% of the electricity used in the state. The continued addition of advanced—and energyintensive—treatment technologies will only add to the increasing electricity costs for water utilities and an increasing supply burden on electric utilities.

ACKOWLEDGMENT Funding for the internship for this project was provided by the Water Industry Technical Action Fund (WITAF). WITAF is administered by AW WA and is funded through AW WA organizational members’ dues. WITAF funds information collection and analysis and other activities in support of sound and effective legislation, regulation, and drinking water policies and programs. ABOUT THE AUTHORS

Stephen J. Reiling (to whom correspondence should be addressed) is a graduate student at the University of Maryland, College Park, MD, 20742; [email protected]. Reiling accepted the WITAF internship for this project to ful-

fill the scholarly practicum requirement to obtain his Master of Engineering and Public Policy (MEPP) degree from the University of Maryland. Prior to entering the MEPP program, Reiling worked as a water resources and project engineer for several engineering consulting firms in the Washington metropolitan area.

J. Alan Roberson is Director of Security and Regulatory Affairs for AWWA in Washington. John E. Cromwell III is an economist for Stratus Consulting Inc. in Washington.

REFERENCES

Presidential Documents, 2001. Executive Order 13211. May 18, 2001. Actions Concerning Regulations That Significantly Affect Energy Supply, Distribution, or Use. Fed. Reg., 66:99:28355.

Awwa Research Foundation (AwwaRF), 2005. AwwaRF Featured Topic: Energy Management. http://www. awwarf.org/research/TopicsAnd Projects/topic Snapshot.aspx?topic= EnrgyMgm (accessed Oct. 1, 2008). BCC Research, 2008. Seawater and Brackish Water Desalination. Report MST052A. www.bccresearch.com/report/ MST052A.html (accessed Oct. 1, 2008). BLS (Bureau of Labor Statistics), 2008. Consumer Price Index. www.bls.gov/CPI/ (accessed Oct. 1, 2008). California Energy Commission, 2005. California’s Water–Energy Relationship. CEC700-2005-011-SF. www.energy.ca. gov/2005publications/ CEC-700-2005-011/CEC-700-2005011-SF.PDF (accessed Oct. 1, 2008). CCAR (California Climate Action Registry), 2008. www.climateregistry.org/about. html (accessed Dec. 5, 2008). EIA (Energy Information Administration), 2009. Monthly Energy Review, January 2009, Table 7.1 Office of Energy Markets and End Use, US Department of Energy, Washington. www.eia.doe.gov/mer/ pdf/mer.pdf (accessed Feb. 9, 2009) EIA, 2007. Annual Energy Review, page 257. www.eia.doe.gov/emeu/aer/pdf/ pages/sec8_39.pdf (accessed Oct 10, 2008). EIA, 2005. Subsequent Events: California’s Energy Crisis. www.eia.doe.gov/cneaf/ electricity/california/subsequentevents. html (accessed Oct. 10, 2008). EIA, 2003. Electricity Transmission Fact Sheet. www.eia.doe.gov/cneaf/electricity/page/fact_sheets/transmission. html (accessed Oct. 10, 2008). MPI (Malcolm Pirnie Inc.), 2008. National Cost Implications of a Potential Perchlorate Regulation. www.awwa.org/ files/secure/index.cfm?FileID=143035 (accessed Oct. 14, 2008).

Date of submission: 10/16/08 Date of acceptance: 12/11/08

Raucher, R.S.; Cromwell III, J.E.; Cooney, K.; Thompson, P.; Sullivan, L.; Carrico, B.; MacPhee, M.; & Wilkinson, R., 2008. Risk and Benefits of Energy Management for Drinking Water Utilities. AwwaRF, Denver. Roberson, J.A., 2006. From Common Cup to Cryptosporidium: A Regulatory Evolution. Jour. AWWA, 98:3:198. Roberson, J.A., 2003. Complexities of the New Drinking Water Regulations— Everything You Wanted to Know but Were Afraid to Ask. Jour. AWWA, 95:3:48. SNWA (Southern Nevada Water Authority), 2008. Clark, Lincoln, and White Pine Counties Groundwater Development Project. www.snwa.com/html/system_ gdp.html (accessed Oct. 1, 2008). State of California, 2008. California State Water Project Overview. State of California Department of Water Resources. www.water.ca.gov/swp/ (accessed Sept. 30, 2008). USDOE (US Department of Energy), 2006. Energy Demands on Water Resources: Report to Congress on the Interdependency of Energy and Water. www. sandia.gov/energy-water/docs/121RptToCongress-EWwEIAcommentsFINAL.pdf (accessed Oct. 1, 2008). USEPA (US Environmental Protection Agency), 2008. Ensuring a Sustainable Future: An Energy Management Guidebook for Wastewater and Water Utilities. www.epa.gov/waterinfrastructure/ pdfs/guidebook_si_energymanagement. pdf (accessed Sept. 30, 2008).

FOOTNOTES 1 Average

national costs available from the Energy Information Administration— Official Energy Statistics from the U.S. Government. www.eia.doe.gov/cneaf/ electricity/epm/tables1a.html. 2 National production figures available at Energy Information Administration/ Monthly Energy Review January 2009. www.eia.doe.gov/emeu/mer/pdf/pages/ sec7_3.pdf. 3Regulations.gov. www.regulations.gov. 4US Environmental Protection Agency; Water; Docket. www.epa.gov/ow/docket.html.

USEPA, 2006c. Groundwater Rule; Final Rule. Fed. Reg., 71:216:65573. USEPA, 2005a. Economic Analysis for Long-Term 2 Enhanced Surface Water Treatment Rule. EPA-821-R-06-001. USEPA, Office of Water, Washington. USEPA, 2005b. Technologies and Costs Document for the Final Long Term 2 Enhanced Surface Water Treatment Rule and Final Stage 2 Disinfectants and Disinfection Byproducts Rule. Office of Ground Water and Drinking Water, Washington. USEPA, 2002. Long Term 1 Enhanced Surface Water Treatment Rule; Final Rule. Fed. Reg., 67:9:1812. USEPA, 2000. Cost And Technology Document For The Proposed Long Term 1 Enhanced Surface Water Treatment And Filter Backwash Rule. Office of Ground Water and Drinking Water, Washington. USEPA 1998a. State 1 Disinfectants and Disinfection Byproducts Rule. Office of Ground Water and Drinking Water, Washington. USEPA, 1998b. Regulatory Impact Analysis for the Stage 1 Disinfectants and Disinfection Byproducts Rule. Office of Ground Water and Drinking Water, Washington. USEPA, 1998c. Regulatory Impact Analysis for the Interim Enhanced Surface Water Treatment Rule. Appendices to the RIA. June 24. Office of Ground Water and Drinking Water, Washington. USEPA, 1998d. Regulatory Impact Analysis for the Interim Enhanced Surface Water Treatment Rule. Final IESWTR RIA. November 12. Office of Ground Water and Drinking Water, Washington.

USEPA, 2006a. Stage 2 Disinfectants/Disinfection Byproducts Rule; Final Rule. Fed. Reg., 71:2:387.

USGS (US Geological Survey), 2004. Estimated Use of Water in the United States in 2000. pubs.usgs.gov/ circ/2004/circ1268/ (accessed Sept. 30, 2008)

USEPA, 2006b. Long Term 2 Enhanced Surface Water Treatment Rule; Final Rule. Fed. Reg., 71:3:653.

Webber, M.E., 2008. Energy Versus Water: Solving Both Crises Together. Scientific American, October 22, 2008.

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