Social cost impact assessment of pipeline infrastructure projects

Environmental Impact Assessment Review 50 (2015) 196–202

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Environmental Impact Assessment Review journal homepage: www.elsevier.com/locate/eiar

Social cost impact assessment of pipeline infrastructure projects John C. Matthews a,⁎, Erez N. Allouche b, Raymond L. Sterling b a b

Battelle, 7231 Palmetto Dr, Baton Rouge, LA 70808, United States Louisiana Tech University, United States

a r t i c l e

i n f o

Article history: Received 26 February 2014 Received in revised form 3 October 2014 Accepted 8 October 2014 Available online 28 October 2014 Keywords: Social costs Construction Pipeline infrastructure Trenchless technology

a b s t r a c t A key advantage of trenchless construction methods compared with traditional open-cut methods is their ability to install or rehabilitate underground utility systems with limited disruption to the surrounding built and natural environments. The equivalent monetary values of these disruptions are commonly called social costs. Social costs are often ignored by engineers or project managers during project planning and design phases, partially because they cannot be calculated using standard estimating methods. In recent years some approaches for estimating social costs were presented. Nevertheless, the cost data needed for validation of these estimating methods is lacking. Development of such social cost databases can be accomplished by compiling relevant information reported in various case histories. This paper identifies eight most important social cost categories, presents mathematical methods for calculating them, and summarizes the social cost impacts for two pipeline construction projects. The case histories are analyzed in order to identify trends for the various social cost categories. The effectiveness of the methods used to estimate these values is also discussed. These findings are valuable for pipeline infrastructure engineers making renewal technology selection decisions by providing a more accurate process for the assessment of social costs and impacts. © 2014 Elsevier Inc. All rights reserved.

Introduction Trenchless technology is a family of construction methods, materials, and equipment that can be used for the installation of new, or rehabilitation of existing, underground utility systems with minimal surface disruption and destruction resulting from the excavation (APWA, 1999). In contrast, open-cut methods can cause significant disruptions to traffic and adjacent commercial and industrial activities. The equivalent monetary values associated with these negative effects are commonly referred to as ‘social costs’ or ‘external costs’. In this paper the term ‘social costs’ is used as a synonym for ‘external costs’. Social costs are thus defined here as costs resulting from construction activities that are born by the community rather than by the contractual parties (Gilchrist and Allouche, 2005). Social costs can range from costs associated with adverse impacts on traffic conditions (e.g., delays and increased vehicle operating expenses), environmental costs (e.g., pollution), costs resulting from decreased safety (e.g., higher rate of traffic accidents and risk to pedestrians), accelerated deterioration of road surfaces (e.g., due to pavement cuts), lower business turnovers, decreased property values, and damage to existing utilities or adjacent foundations. The presence of construction related social costs and the ability of trenchless methods to mitigate these costs are well recognized ⁎ Corresponding author. E-mail addresses: [email protected] (J.C. Matthews), [email protected] (E.N. Allouche), [email protected] (R.L. Sterling).

http://dx.doi.org/10.1016/j.eiar.2014.10.001 0195-9255/© 2014 Elsevier Inc. All rights reserved.

(Bottero and Peila, 2005; Boyce et al., 1998; Fea et al., 2000; Islam et al., 2013, 2014; Matthews, 2010; McKim, 1997; Sterling, 1994). However, designers and owners rarely take social costs into account during a construction project's planning, design and bid evaluation phases. One rationale is that social costs cannot be calculated using standard estimating methods (Xueqing et al., 2008). In recent years, several attempts have been made to introduce approaches and methodologies for predicting social costs associated with utility construction projects (Brady et al., 2001; CERIU, 2010; Gangavarapu and Najafi, 2004; Gilchrist and Allouche, 2005; Grunwald, 1997; Islam et al., 2014; Matthews and Allouche, 2010; Michielsen, 2005; Tighe et al., 1999). Nevertheless, unit cost data needed for the verification and validation of such prediction methods is lacking. This paper presents an overview of eight social cost categories. Two case histories of utility construction projects are introduced and discussed. Information provided for each case study includes: a) project background; b) reported social cost categories; and c) estimated monetary values for each category. The case histories are analyzed and compared in order to identify trends and derive typical cost values and cost ranges. Methods used to compute the various social cost values are also compared, and their effectiveness and viability are discussed. Social cost categories Eight social cost categories are considered in this paper. While other social cost categories could be relevant, the eight considered appear to be both common to many utility construction projects as

J.C. Matthews et al. / Environmental Impact Assessment Review 50 (2015) 196–202

well as suitable for quantitative evaluation in a reasonably systematic manner. Travel delay Utility construction work can cause significant traffic delay due to lane closures or complete road closures forcing detours. Pedestrians also can be forced to detour due to re-routing of public transportation services and blocked sidewalks. Brady et al. (2001) estimated the annual costs of traffic disruption arising from utility work in the U.K. alone to be £2 billion. Delay costs for traffic can be calculated using the following equation: DC t ¼ VT  Nv  ITT  Dh

ð1Þ

where DCt is the delay costs for traffic [$]; VT is the value of time [$/h]; Nv is the number of vehicles [vehicles/h]; ITT is the increased travel time [h/vehicle]; and Dh is the project duration [h]. Increased travel time (ITT) or travel delays can be measured directly at the project site or can be calculated using established principles. For the case of partially obstructed roadways (i.e., ignoring detour delays), Tighe et al. (1999) defined user delays as both slowing delays caused by the reduced speed through the affected area and queuing delays due to congestion when traffic demands exceed roadway capacity. The Highway Capacity Manual provides calculation procedures for determining such delays (TRB, 2000). Selecting the most appropriate procedure for determining the anticipated delay requires knowledge of the roadway configuration and number of lane closures. A procedure for determining delays in a two-lane road, with one-lane closed down, and flag people at each end of the closed section, is presented below in detail for illustration purposes. The normal capacity of the roadway is determined by considering the number of heavy vehicles traveling on that road: NC ¼ 1700=HV

ð2Þ

197

where the values for green times (Green) and cycle times (Cycles) for a range of average annual daily traffic (AADT) values are listed in Table 1. The hourly volumes for both peak and off-peak hours are computed next: HV P ¼ AADT  k  0:5

ð5aÞ

HV OP ¼ ½ðAADT–ðHV P  PH ÞÞ=ð24–PH Þ  0:5

ð5bÞ

where HVP = peak hourly volume [vehicles/hour]; HVOP = off-peak hourly volume [vehicles/hour]; k = area adjustment factor [0.1 for urban areas & 0.09 for rural areas]; PH = peak hours [hours]; and the constant of 0.5 is used to account for the lane which is closed down. Finally, delays are calculated for both peak and off-peak hours as follows: DP ¼

h



 i 2 =ð1–ðX P  ðGreen=CycleÞÞÞ =3600 ð0:5  CycleÞ  ð1–ðGreen=CycleÞÞ

ð6aÞ

DOP ¼


 h
i 2 =ð1–ðX OP  ðGreen=CycleÞÞÞ =3600 ð0:5  CycleÞ  ð1–ðGreen=CycleÞÞ

ð6bÞ where DP and DOP are the delays during peak and off-peak hours respectively [hours]; XP = HVP/RC; XOP = HVOP/RC; and 3600 = conversion factor [seconds/hour]. The total delay is simply the summation of the peak and off-peak delays. This delay can then be used in Eq. (1) to calculate the cost due to traffic delays. In the case of highly urbanized areas with extensive surface public transportation systems, delay costs for pedestrians could be a significant factor. These can be computed using the following expression: DC p ¼ VT  N p  ITT  Dh

ð7Þ

where NC = normal capacity for two-lane road [vehicles/hour/lane]; 1700 = capacity of passenger cars per hour per lane in ideal conditions [cars/hour/lane]; and HV is the adjustment factor for heavy vehicles, computed by the following equation:

where DCp = delay costs for pedestrians [$]; Np = number of pedestrians [person/h], VT = value of time [$/h]; ITT = increased travel time [h/person]; and Dh = project duration [h].

HV ¼ 1=ð1 þ ð F HV  0:5ÞÞ

Vehicle operating costs

ð3Þ

where FHV is the fraction of heavy vehicles in the vehicle stream. Next, the reduced capacity of the roadway, RC [vehicles/hour/lane], is determined as follows: RC ¼ NC  ðGreen=CycleÞ

ð4Þ

Longer travel distances and stop-and-go traffic result in higher vehicle operating costs. For example, 1000 speed changes from 80 km/h to 24 km/h and back to 80 km/h cause an additional fuel consumption of 55 l for light duty vehicles (Budhu and Iseley, 1994). Vehicle operating costs can be calculated using the following expression: VOC ¼ ITD  OCA  Nv  Dh

ð8Þ

where VOC = vehicle operating costs [$]; ITD = increased travel distance [km]; OCA = operating cost allowance [$/(km vehicle)]; Nv = number of vehicles [vehicles/h]; and Dh = project duration [h].

Table 1 Green times and cycle lengths based on AADT. AADT

Green time (s)

Cycle length (s)

b3500 3500–4000 4000–6500 6500–7000 7000–7500 7500–8000 8000–8500 8500–9000 9000–9500 9500–10,000

100 150 250 300 350 400 450 500 570 610

400 500 700 800 900 1000 1100 1200 1340 1420

Decreased road surface value Open excavations can result in pavement deformations and asphalt cracking at the edges of the trench, which leads to an accelerated degradation of the pavement. Reduction in useful pavement life due to an open-cut excavation is estimated to be as high as 30% (Tighe et al., 2002). Kolator (1998) proposed the following expression for calculating the average decrease in the road surface value: RSV ¼ Ls  110 ½D=m

ð9Þ

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where RSV = decreased road surface value; and Ls = length of excavation [m]. An average value of 110 [$/m] was suggested by the author for a rapid estimate of the decrease in road surface value.

can also affect social, behavioral, mental and physical health (Bein, 1997). A simplified expression for calculating the cost associated with noise pollution is:

Lost business revenue

CNP ¼ Ni  Dd  ðNC c – NC n Þ

Construction zones can decrease the accessibility to businesses due to congested traffic conditions, lost parking spaces and physical barriers associated with construction activities. On the one hand, businesses lose customers who prefer to go to more convenient places, while on the other hand businesses that depend on regular deliveries may experience difficulties with their inventory levels. The adverse impact can be especially severe for ‘convenience’ businesses that depend on traffic flow such as restaurants, coffee shops and gasoline refueling stations.

where CNP = costs of noise pollution; Ni = number of disturbed inhabitants; NCc = noise cost value for construction work [$/day]; and NCn = noise cost value for the pre-construction situation [$/day].

LBR ¼ IF  TW  Dw

ð10Þ

where LBR = lost business revenue [$]; IF = impact factor; TW = turnover per week [$/week]; and Dw = project duration [weeks].

Loss of parking spaces leads to lower revenues from parking meters and parking fines for the municipality. In downtown Paris, France, the cost of occupation of 1 m2 of parking space for 1 h was estimated to be 0.09–0.18 USD (0.5–1 FF) (Diab and Morand, 2001). Loss of parking meters (LPM, $) and parking fines (LPF, $) based revenue to the municipality can be estimated by: LPM ¼ NPS  MR  O  Dh

ð11aÞ

LP F ¼ T F  FOT  Dh

ð11bÞ

where NPS = number of lost parking spaces; MR = meter rate [$/h]; O = % of occupancy; TF = ticket fine [$/ticket]; and FOT = frequency of ticketing [tickets/h]. Cost of dust control Open excavations result in a significant amount of dust in their surroundings, causing increase in cleaning needs. Also, the quality of life for people living near the construction zone decreases. Additional cleaning costs can be expressed as: CDC ¼ AC  WR  Dw

ð12Þ

where CDC = costs of dust control [$]; AC = additional cleaning time [h/week]; WR = wage rate [$/h]; and Dw = project duration [weeks]. Alternatively, Kolator (1998) proposed the following expression for CDC ($): CDC ¼ 2  Lb  H b  W  C F  CC

Safety Continuous open trenches pose a higher risk to workers and pedestrians compared with the pits/shafts employed by trenchless construction methods. Accidents related to trenching are approximately 112% higher than the average value for the construction sector, with more than 60 workers killed in trenching accidents in the US each year (Jung and Sinha, 2004). The compensation insurance rate for a particular project can be calculated using: CWR ¼ IP  PR  M  Nw  WD  Dd

Loss of parking revenues

ð13Þ

where Lb = length of buildings next to construction zone [m]; Hb = height of buildings next to construction zone [m], W = share of windows [%]; CF = correction factor; and CC = costs of cleaning [$/m2]. Noise pollution costs The use of heavy construction equipment results in a higher noise level in the vicinity of the work area (Ballesteros et al., 2010; Gilchrist et al., 2003). In addition, construction work may lead to a higher noise pollution due to changing traffic conditions compared with the baseline traffic flow circulation patterns. An increase of 1 dBA leads to a decrease in housing value estimated at 0.4% (TRB, 1996). Increased noise level

ð14Þ

ð15Þ

where CWR = costs of higher worker risk [$]; IP = insurance premium [$/$ of payroll]; PR = payroll [$/h]; M = multiplier for individual pain, suffering, wage loss; Nw = number of workers; and WD = working hours per day [h/day]. Case History I — storm drain replacement, Oakland, California Boyce and Bried (1994) calculated the social costs for a storm drain replacement project, which took place in Oakland, California, US. The replacement gravity line was 2134 mm and 2286 mm in diameter and was installed at depths from 3.6 to 6.0 m. The new gravity line was constructed along three roads, passing residential areas and a popular shopping center. The shopping area consisted of 39 businesses, ranging from clothing stores and restaurants to specialty shops. For calculation purposes, only one street was considered — the street where the businesses were located. The total project duration for all different portions was 154 days (06/15/1993 to 11/15/1993). The segment considered was completed in 98 days (06/15/1993 to 09/20/1993). The pipe length used in the calculation is 654 m. The social costs were calculated for two different construction methods, namely trenching and microtunneling. The trenching scenario actually took place. In the case of microtunneling, it was assumed that 244 m was to be constructed in a trenchless manner. For the remaining 410 m, the open-cut method was to be used. For the trenching scenario, a complete road closure was necessary and the cars had to take a 0.64 km detour. The travel time increased on average by 2 to 3 min. For the microtunneling scenario, the road did not have to be closed and so it was assumed that no detours or delays occurred. The lost business revenue for the 39 businesses is verbally described, but it was not possible to derive actual cost data. The same is true for loss of productivity due to construction noise. Project characteristics, social costs, direct costs and costs per unit length and construction day for this case history are listed in Table 2. Case History II — sewer replacement, Kessel-Dorp, Belgium Michielsen (2005, 2006) described the upgrade of a sewer system in Kessel-Dorp, Belgium. This combined sewer system, consisting of a collector and service lines (laterals), was replaced with a separated sewer system by adding a new wastewater collector, and re-installing the laterals. Two different construction methods were considered, namely open-cut and pipe jacking. Using the pipe jacking alternative it was possible to tunnel the new collector below the existing collector, which was converted to a storm drain. Sewer laterals were connected to a 300 mm

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Table 2 Cost data for Case History I.

Project characteristics Project duration Construction days Pipe length Pipe diameter Trench depth Traffic data Street type Traffic control Traffic volume Persons/car Pedestrians Number of lost parking spaces General cost data Value of lost time/road user Value of lost time/pedestrian Operating cost allowance Wage rate cleaning personal Direct contract costs Costs/meter placed pipe Social costs Vehicle operating costs Costs due to travel delay Cost of pedestrian disruption Cost of dust and dirt control Lost parking meter revenue Lost parking ticket revenue Worker safety Total social costs Costs/meter placed pipe Costs/construction day % direct contract costs Total costs Costs/meter placed pipe

Unit

Open cut

Microtunneling

[days] [days] [m] [mm] [m]

98 70 654 2134–2286 3.6–6.0

98 70 244 (410 open cut) 2134–2286 3.6–6.0

Urban streets Complete road closure, detour 14,160 AADT 1.25 30 22 (49 days), 44 (49 days)

Urban streets No permanent road closures 14,160 AADT 1.25 30 4 (98 days)

[cars/day] [pers./h]

[$/h] [$/h] [$/km] [$/h] [$]

12.67 12.67 0.27 30.16 1,784,962

[$/m]

2729

[$] [$] [$] [$] [$] [$] [$] [$] [$/m] [$/day] [%] [$] [$/m]

152,703 457,723 37,238 8233 16,719 36,415 79,818 787,849 1205 11,255 44 2,572,811 3934

dia. local sewer using the open-cut method, which was then connected to the new wastewater collector using microtunneling. In the pipe jacking scenario, the collector diameters were to be 600 mm, 1200 mm. and 1600 mm. Alternatively, utilizing open cut required constructing all new system components, including the wastewater collector, the storm water collector, and all lateral connections. In the opencut scenario, the collector diameters were 1200 mm and 1600 mm. The trench depth for the installation of the new collectors ranged from 2.9 to 4.4 m. For both construction methods, it was necessary to close a part of the road where the construction work took place, and traffic had to be detoured. The detour resulted in an increased travel distance of 11.7 km. Using the open-cut method, it was necessary to partially or fully close down the road for 8 months, whereas, using the pipe jacking method a closure of only 1 month was needed. To determine the impact on the traffic volume in the road directly affected by the construction work as well as on the diversion route, traffic measurements were conducted before the construction project started and during the construction process. Traffic was required to detour and travel an additional 11.7 km compared to the pre-construction scenario. Travel delay costs were calculated using Eq. (1), similar to the other case histories. The value of lost time was determined to be $69/h for trucks, $34/h for delivery vans and $21/h for passenger cars. Sixty businesses were located in the vicinity of where the construction project took place. Approximately 1/3 of the businesses were independent merchants and the balance corporate merchants. The total annual turnover for all businesses was estimated to be 3.4 million EUR. To determine the merchants' loss, it was estimated that a merchant loses 70% of its sales revenue if its business location is inaccessible and 33% if its business location is difficult to access. It was assumed that

1,500,008 (microtunneling) 1,027,304 (open cut) 6148 (microtunneling) 2506 (open cut) 0 0 0 0 579 0 57,204 57,782 88 825 2 2,585,095 3953

merchants may adapt their sales policies to the new situation and the author introduced a maximum net loss in sales margin of 50% to avoid overestimation. Table 3 summarizes the cost data and project characteristics for Case History II. Discussion When social costs are accounted for, the trenchless construction alternative is comparable to open-cut for both case histories. This is partly because both projects took place in high density urban areas where social costs are significantly higher for water infrastructure projects. When a trenchless construction method was used, social costs were found to account for 1 to 9% of the total construction costs. Thus, social costs can be considered to have limited significance in the case of trenchless construction methods. Therefore, the following discussion focuses on the social costs associated with the open-cut construction alternative for the case histories described above. It should be noted that the case studies are site and project specific, and the analysis presented may not apply in all the cases. For these case histories, the most important social cost category is travel delay costs, representing on average 18% of the total construction costs and 55% of the total social costs. The social cost category with the second largest share is vehicle operating costs ranging from 6 to 14% of the total social costs. The most important social cost category not linked to traffic is typically business revenue, which was found to account for between 4% and 6% of the total construction costs for case 2. Other social cost categories like dust and dirt control, worker safety, noise pollution costs, decreased road surface value, lost parking spaces and cost of uneasiness for residents seem to have a more limited economic impact, collectively accounting for 7.5% of the total construction costs on an average.

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Table 3 Cost data for Case History II.

Project characteristics Project duration Construction days Pipe length Pipe diameter Trench depth Traffic data Street type Traffic control Increase in travel distance General cost data Value of time/vehicle

Unit

Open cut

Pipe jacking

[days] [days] [m] [mm] [m]

300 216 2500 1200; 1600 2.9–4.4

200 144 2500 600; 1200; 1600 Pipe is placed deeper than open-trench

[km]

Urban street Road closure (8 months) 11.7

Urban street Road closure (1 month) 11.7

[$/year] [$] [$/m]

69 (trucks), 34 (delivery vans), 21 (passenger car) 4,117,223 5,540,539 2216

69 (trucks), 34 (delivery vans), 21 (passenger car) 4,117,223 7,162,689 2865

[$] [$] [$] [$] [$] [$/m] [$/day] [%] [$] [$/m]

557,488 1,830,985 553,159 566,771 3,508,403 1403 16,243 63 9,048,943 3620

68,920 490,231 68,385 70,073 607,609 279 4845 10 7,860,298 3144

[$/h]

Annual business turnover Direct contract costs Costs/meter placed pipe Social costs Increased fuel costs Costs due to detour Time costs due to increased traffic on detour route Lost business revenue Total social costs Costs/meter of placed pipe Costs/construction day % direct contract costs Total costs Costs/meter placed pipe

McKim (1997) presented a method for a rapid estimation of social costs in open-cut and trenchless construction projects. He estimated that social costs for open-cut equal 78% of the direct construction costs and social costs for trenchless account for 3% of the direct costs. The results for high density urban environment for the case studies considered in this paper suggest that social costs represent about 55% of the direct costs when open-cut construction is used and 6% of the direct costs when trenchless technology is used. While more cases are needed to narrow the range for the open-cut method, it is clear that social costs associated with trenchless construction usually are small compared with those associated with open-cut construction. For calculation of social costs, a database of typical cost data is necessary. An important value is the monetary value used to calculate the costs of time lost due to travel delay. The values applied in the case studies range from $10/vehicle–hour to $16/vehicle–hour for a traffic mixture of cars and freight transportation. Michielsen (2005) separates cars and freight traffic. He uses $69/vehicle–hour for trucks, $34/vehicle–hour for delivery vans and $21/vehicle–hour for passenger cars. A study on the calculation of user delays due to construction work conducted at the Kentucky Transportation Center reports average values for user delay costs based on various sources (Rister and Graves, 2002). Values reported and adjusted to March 2011 are: $16/vehicle–hour for cars, $28/vehicle–hour for single unit trucks, and $34/vehicle–hour for combination unit trucks. The wide range of values is due to the different regions (i.e., U.S. and Belgium) being represented in the data.

Table 4 Minimum and maximum unit cost values per meter placed pipe and construction day. Social cost category

Number of data points

Min. [$/m]

Max. [$/m]

Min. [$/day]

Max. [$/day]

Vehicle operating costs a Travel delay costs Dirt control costs Parking meter revenue Decreased road surface value Noise pollution costs Lost business revenue

4 5 3 3 2 2 2

7 10 13 22 57 −9 161

232 806 56 34 125 2 226

29 45 61 91 249 −24 433

2581 8477 149 239 334 8 2624

a

Social cost category for which explicit calculations are required.

Based on case histories, unit cost data for the presented social cost categories was derived for unit length and construction day, to see if a rapid cost estimate for these categories can be obtained. Table 4 summarizes the minimum and maximum values per linear meter of placed pipe and per day of construction work for social cost categories used in more than one case study. It can be seen that for traffic delay related categories values range widely as they are a function of multiple factors such as average annual daily traffic (AADT), vehicle mix and length of detour. For this category a unit cost approach is not suitable and social costs need to be calculated explicitly based on the project particulars using Eqs. (1)–(8). This is also the case for the lost business revenue category, where the type and number of influenced businesses greatly affect estimated social cost value. On the other hand, for the categories of dust control, decreased road surface value, lost parking revenues and noise pollution the calculated cost values are within relatively narrow ranges and a unit cost approach might be suitable, greatly simplifying the needed calculations for these categories. Also, a unit cost approach using length of installation ($/m) rather than anticipated duration ($/day) seems to provide a narrower range for all categories. Consistent through all the case studies was the method used for the calculation of travel delay costs. The cost calculation was based on the number of vehicles, the increased travel time due to construction activities, a monetary value for the time lost ($/vehicle–hour) and the project duration. The most challenging factor to determine is the increased travel time, because it is a function of the pre-construction traffic volumes in the affected and alternative routes, as well as of the lengths of these alternatives. A simplified approach for calculating this factor was presented in this paper. In addition, several computer programs for the determination of travel delay due to road construction work are available (FHWA, 2005; Rister and Graves, 2002; TTI, 1998). However, these programs may require a significant amount of input data. This factor could be taken into account by the engineer during the design phase of the project. Multiple approaches were used for calculating the increase in vehicle operating costs. The calculations in case 1 is based on an operating cost allowance whereas for case 2 was based on increased fuel consumption due to longer travel distances and/or increased travel times. Fuel costs represent only one aspect of a vehicle operating cost. Other

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contributing costs like maintenance or tire wear should also be considered. The authors suggest using the ‘marginal cost approach’ which considers the cost of driving a vehicle an additional mile. This method accounts for fuel consumption, routine maintenance, tires, repairs and depreciation (Barnes and Langworthy, 2003). This factor could also be taken into account by the engineer during the design phase of the project. By controlling the impact to vehicles and motorists, the engineer can have the largest control of social costs by taking these factors into account during the design phase. For the remaining factors, some would best controlled by the contractor during construction (i.e., dirt control and noise pollution), while others are best controlled by the owner or engineer during planning (i.e., parking revenue and road surface). Social costs may be independent of many of the parameters which control direct costs in utility construction projects such as pipe diameter, depth of installation, elevation of the groundwater table, and soil conditions. Thus, the technical complexity of the project may only have limited influence on social costs. This suggests that social costs in terms of percentage of total costs are more significant in the case of less complex utility projects than in the cases of more complex projects. However, larger scale, more complex construction projects can take longer periods of time and influence greater areas. Therefore the absolute dollar value of the social costs in complex construction projects can still be high. These trends suggest that the inclusion of social costs in the total project costs is likely to make trenchless methods more economic for many small diameter utility installations in dense urban areas. For larger, more complex construction projects an economic analysis on a case-by-case basis is needed. Conclusions A process for calculating eight types of social costs relating to water infrastructure construction projects is presented. The comparison and analysis of two case histories, each presenting an open-cut and trenchless scenario for a utility construction or rehabilitation project, showed that the inclusion of social costs in the project cost estimate could make trenchless technology more advantageous in comparison with open-cut construction. This is especially true for high density urban areas. The distribution and relative weight of social costs were found to be significantly different in projects conducted in high density urban areas compared with a project conducted in a medium density urban area. In dense urban areas travel delay costs are the most important social cost factor, accounting for approximately 55% of the total social costs. The method used for the calculation of traffic delay costs was found to be consistent through the case histories, suggesting wide acceptance of the user delay cost approach. A larger set of case histories is needed to obtain greater confidence in the unit costs for the various social cost categories. A unit cost approach was found to be viable for the following categories: dust and dirt control, decreased road surface value and noise pollution. For other social cost categories, such as travel delay costs and vehicle operating costs, explicit calculations for each project are required. Nevertheless, reliable input data for Eqs. (1)–(8) are available, which allow performing these calculations with relative ease. It was observed that social costs are for the most part independent of many of the parameters which determine direct costs such as pipe diameter, depth of installation, elevation of the groundwater table and soil conditions. Thus, the technical complexity of a project has limited influence on the magnitude of the social costs. Therefore, the relative percentage of social costs is greater for less complex projects involving small diameter pipes with lower direct costs. There is a need to define a set of social cost criteria that will be used to establish a standard for social cost calculation for utility construction that is acceptable to the industry. Moving in this direction is important because the inclusion of social costs in bid invitations and evaluations could support the wider utilization of new construction methods such

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as trenchless technologies, which offer less disruption to the construction environment, as well as promote more sustainable design, construction and maintenance practices for our urban landscapes. To get to that point, a reliable automated approach for estimating social costs based on typical values is recommended for development. Acknowledgments The authors would like to acknowledge the support of research assistant Ms. Johanna E. Pucker who was crucial to the development of the case studies presented here-in. References American Public Works Association (APWA). Trenchless technology applications in public works. 1st ed. Kansas City, MO: APWA; 1999. Ballesteros M, Fernández M, Quintana S, Ballesteros J, González I. Noise emission evolution on construction sites: measurement for controlling and assessing its impact on the people and on the environment. Build Environ 2010;45(3):711–7. Barnes G, Langworthy P. The per-mile costs of operating automobiles and trucks. Final report. MN: Minnesota Department of Transportation; 2003. Bein P. Monetization of environmental impacts of roads. British Columbia, Canada: Ministry of Transportation; 1997. Bottero M, Peila D. The use of the analytic hierarchy process for the comparison between microtunneling and trench excavation. Tunn Undergr Space Technol 2005;20(6): 501–13. Boyce G, Bried E. Benefit cost analysis of microtunneling in an urban area. No-Dig, Dallas, TX. Arlington, VA: North American Society for Trenchless Technology; 1994. Boyce G, Brinckerhoff P, Bried E. Social cost accounting for trenchless projects. No-Dig, Albuquerque, NM. Arlington, VA: North American Society for Trenchless Technology; 1998. Brady K, Burtwell M, Thomson J. Mitigating the disruption caused by utility street works. TRL limited report no. 516, UK; 2001. Budhu G, Iseley D. The economics of trenchless technology vs. the traditional cut and fill in high-density–activity urban corridors — a research concept in a real-world environment. No-Dig, Dallas, TX. Arlington, VA: North American Society for Trenchless Technology; 1994. Centre D'expertise et de Recherche en Infrastructures Urbaines (CERIU). Guide pour L'évaluation des couts Socio-économiques des Travaux de Renouvellement des Conduites D'eau Potable et D'egout. Montreal, Canada: CERIU; 2010. Diab Y, Morand D. An approach for the choice of rehabilitation techniques of urban sewers. Pipelines, San Diego, CA. Reston, VA: ASCE; 2001. Fea P, Gatti F, Giacomello L, Marchisio L, Baldinelli N, Cori C, et al. Environmental and social costs evaluation for innovative dig techniques. No-Dig, Perth, Australia. London, UK: International Society for Trenchless Technology; 2000. Federal Highway Administration (FHWA). QuickZone Delay Estimation Program. Version 2. 0; 2005. Gangavarapu B, Najafi M. Quantitative analysis and comparison of traffic disruption using open-cut and trenchless methods of pipe installation. No-Dig, New Orleans, LA. Arlington, VA: North American Society for Trenchless Technology; 2004. Gilchrist A, Allouche E. Quantification of social costs associated with construction projects: state-of-art-review. Tunn Undergr Space Technol 2005;20:89–104. Gilchrist A, Allouche E, Cowan D. Prediction and mitigation of construction noise in an urban environment. Can J Civ Eng 2003;30:659–72. Grunwald G. Wirtschaftlichkeitsuntersuchungen bei Kanalisierung. PhD thesis at the Ruhr Universitaet Bochum, Germany Institut fuer Kanalisationstechnik; 1997 [April]. Islam A, Matthews J, Allouche E, McKim R. Multi-segment multi-criteria method selection for buried pipelines. ICPTT, Xi'an, China. Reston, VA: ASCE; 2013. Islam A, Allouche E, Matthews J. Assessment of social cost savings in trenchless projects. NoDig, Orlando, FL. Arlington, VA: North American Society for Trenchless Technology; 2014. Jung Y, Sinha S. Trenchless technology: an efficient and environmentally sound approach for underground municipal pipeline infrastructure systems. No-Dig, New Orleans, LA. Arlington, VA: North American Society for Trenchless Technology; 2004. Kolator R. Soziale Kosten im Leitungs- und Kanalbau. PhD thesis at the Vienna University of Technology, Austria Fakultaet fuer Bauingeneurwesen; 1998 [December]. Matthews J. Integrated, multi-attribute decision support system for the evaluation of underground utility construction methods; 2010 [PhD dissertation at Louisiana Tech University, Ruston, LA, March]. Matthews J, Allouche E. A social cost calculator for utility construction projects. No-Dig, Chicago, IL. Arlington, VA: North American Society for Trenchless Technology; 2010. McKim R. Bidding strategies for conventional and trenchless technologies considering social costs. Can J Civ Eng 1997;24:819–27. Michielsen K. Indirect costs of sewer installations: comparison of the total costs of open trench and jacking alternatives based on a specific project. No-Dig, Rotterdam, Netherlands. London, UK: International Society for Trenchless Technology; 2005. Michielsen K. Trench vs. jacking cost comparison. Tunnels Tunn Int 2006;5:23–6. Rister B, Graves C. The cost of construction delays and traffic control for life-cycle cost analysis of pavements. Final report. Lexington, KY: Kentucky Transportation Center, Kentucky University; 2002. Sterling R. Indirect costs of utility placement and repair beneath streets. Final report for MN Department of Transportation, Underground Space Center. Minneapolis, MN: Univ. of Minnesota; 1994.

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J.C. Matthews et al. / Environmental Impact Assessment Review 50 (2015) 196–202

Texas Transportation Institute (TTI). QUEWZ-98. Software; 1998 [May]. Tighe S, Lee T, McKim R, Haas R. Traffic delay cost savings associated with trenchless technology. J. Infrastruct. Syst., 2 Reston, VA. ASCE; 1999. p. 45–51. Tighe S, Knight M, Papoutsis D, Roriguez V, Walker C. User cost savings in eliminating pavement excavations through employing trenchless technologies. Can J Civ Eng 2002;29:751–61. Transportation Research Board (TRB). Paying our way — estimating marginal social costs of freight transportation. Special report 246. Washington, D.C.: National Research Council; 1996 Transportation Research Board (TRB). Highway capacity manual. 4th ed. Washington, D.C.: National Research Council; 2000 Xueqing W, Bingsheng L, Allouche E, Xiaoyan L. A practical bid evaluation method considering social costs in urban infrastructure projects. IEEE International Conference on Management of Innovation & Technology, Bangkok, Thailand; 2008. p. 617–22.

Dr. Matthews has over ten years of experience in the rehabilitation and inspection of infrastructure systems. He has served as Battelle's technical lead on multiple water and wastewater infrastructure studies for four over years. Prior to joining Battelle, he led multiple projects while at the Trenchless Technology Center (TTC) relating to the development of automated decision support systems for technology selection. He was also involved in projects relating to condition assessment technology selection and field evaluation of rehabilitation technologies. He also has experience as a field inspector for rehabilitation and replacement construction projects. He has given more than 65 conference presentations and authored more than 100 publications. He is a member of the North American Society for Trenchless Technology (NASTT), American Society of Civil Engineers (ASCE), and American Water Works Association (AWWA).