Journal of Environmental Science, Computer Science and
Engineering & Technology
An International Peer Review E-3 Journal of Sciences and Technology
Available online atwww.jecet.org
Section A: Environmental Science
Research ArticleEvaluation of Construction Noise at Selected Highway Road
Construction Sites in Urban City of Port Harcourt and Its
Effects on Residential Environment
Ugbebor J. N.
1, Promise
1, B.Yorkor
21
Department of Environmental Engineering, Faculty of Infrastructure System Engineering, University of Port Harcourt, Nigeria 2School of Basic Studies, University of Port Harcourt, Nigeria
Received: 19 March 2015; Revised: 28 May 2015; Accepted: 22 June 2015
Abstract: Construction activities often generates noise that arouse complaints from local
residents, such complaints typically arise from interference with people’s activities and comfort, especially when the residents have no clear understanding of the extent or duration of the construction. This study measured the noise levels generated at selected construction sites along the East-West Highway, Port Harcourt. Noise impacts from construction activities have been estimated using Federal Highway Administration (FHA) construction noise prediction model. Results obtained indicated that measured maximum noise exceeded FMEnv exposure limit 40% of the monitoring time at Nkoplu site, 30% of monitoring time at Rukpakwulushi site and 10% of monitoring time at Eleme junction construction site. About 94 % of the predicted values of the noise levels using the FHA model were close to the measured values with a range of 5% error. The study revealed that residents’ environment experienced moderate to high noise pollution during period of construction which may cause hearing impairment and some psychological effects on residents and those doing business around the construction sites. Thus, alternative procedures of construction and selection of combination of techniques that generate the least overall noise should be implemented. Also, moveable noise barriers should be positioned along construction sites so as to protect the resident environment.
Keywords: Construction Noise, East-West Highway, social survey, noise pollution. INTRODUCTION
One of the consequences of improperly planned cities is the pollution of the environment and consequent degradation of the quality of life1. Noise pollution is a significant environmental problem in many rapidly growing urban cities of developing countries. It is well established now that noise is a potential hazard to health, communication and enjoyment of social life. It is becoming an unjustifiable interference and imposition upon human comfort, health and quality of modem life2.
Construction activity, despite the limited time frame over which it takes place often generates noise that arouse complaints from residents within the construction site. Construction noise may not pose immediate or acute health risk or damage peoples' sense of hearing, but it can adversely affect peoples' quality of life3. To some degree, construction noise can be a contributing factor to the degradation of someone's health in that it can cause people to be irritated and stressed and can interrupt their ability to sleep - all of which may lead to higher blood pressure, anxiety, and feelings of animosity toward the people or agencies responsible for producing the noise3. Construction noise has the potential to disturb people in their residences, in offices or retail businesses; it can also disturb people in public institutional buildings, at locations of religious services, while attending sporting events, or when on vacation.
MATERIALS AND METHODS
The following regulatory frameworks were used as basis for noise levels comparison.
a. Nigerian National Environmental Noise Standards and Control Regulations, 2009. S. I. No. 354. The main objective of the provisions of this Regulation is to ensure tranquility of the human environment or surrounding and their psychological well-being by regulating noise levels5,
b. Noise impact criteria for different land uses close to highways established by US Federal Highway Administration3and
c. WHO Noise Level Guidelines6.
Field Surveys and measurement: A total of Three (3) locations where construction activities were on
going were identified along the East-West Highway during field survey. An hourly data recording interval carried out for Eight (8) hours as recommended by FMEnv4andWHO6. Monitoring locations are as shown in the Table 1.
Table 1: Monitoring Location
S/N Location Coordinate
1 Nkpolu construction site N4052'7.090" E6059'0.564" 2 Rukpakwulushi construction site N4051'36.930" E7001'04.596" 3 Eleme junction construction site N4051'40.626" E7003'40.014"
Instruments: SMART SENSOR (Model AR854) and TES (Model 1352H) sound level meters/data
loggers, (which logged data continuously over the period) were used to measure Sound Pressure Levels noise levels in each location. The equipment measure noise via microphone probe that generates signals appropriately proportional to sound waves. Measuring range: 30~130dBA, - Accuracy:+/-1.5dB;Resolution:0.1dB Frequency range: 20Hz to 8.5KHz. the noise meters were calibrated to assure that they were within calibration tolerances.
Construction Noise Measurement Procedure: Monitoring was carried out at pre-determined locations
(as shown in Table 1). Values of Sound Pressure Levels at each monitoring location were obtained and recorded using Programmable Noise meter, which gives instant, real time readings. Monitoring of sound pressure levels was carried out for 8 hours (15-minutes average sampling).Measurement instrument were placed between 3 to 10 meters high above the ground in accordance with NSW7noise measurement procedure.
The monitoring exercise was conducted and 10 sets of reading were taken at each location during the period given a total number of 30 sets of reading. Based on these, maximum readings, L
Max, average
noise levels Lav and equivalent continuous noise levels, L
eqwith standard deviation were determined
individually for each monitoring location.
Noise Impact Assessment, Analysis and Prediction: Environmental noise usually varies in level over
time; results of environmental noise monitoring are therefore analyzed using mathematical and statistical descriptors. The following mathematical and statistical tools were used for the analysis of collected field data.
Mathematical and Statistical Noise Level Description: The following mathematical and statistical tools
were used for the analysis of collected field data.
Averaging Sound Pressure Levels: because of the logarithm nature of the decibel, average values of
sound pressure levels were computed using Equation (1)8.
...N 1,2,3,.... j ) 20 : ref dB (in levels pressure sound jth the L ts measuremen of number N Pa) 20 : ref dB (in level pressure sound average L where 10 1 log 20 j av 1 20 = = = = =
∑
= Pa N L N j L av j µ µ (1) The Standard Deviation, S, of data variance is calculated using the computational equation (3.2) − − − =
∑
∑
= = 1 1 1 2 1 1 2 N x x N s N i i N i i (2)Where N is the number of measurements
Equivalent continuous equal energy level (Leq) - A-weighted sound pressure level
The Equivalent continuous equal energy level (Leq) is computed using the following expression 9 .
( )
t time measuremen total of fraction t taken ts measuremen of number total the n t measuremen ith the of dB(A) in level noise the Li where 10 log 10 i 1 10 = = = =∑
= = n i i i L eq t L t (3) Noise Pollution Level, Lnp, was estimated from the values of NLx. using the following model10
.
(4)
Where K is a constant with a value of 2.565 for this kind of environment and σ is the standard deviation of the obtained leq values11. It has been found that the value of Lnp is higher than the
maximum value of field measurements and thus serves as a useful tool in noise pollution modelling and regulations12.
Noise from Typical Construction Equipment: The equivalent sound level (LeqEquipment) as it relates to
construction activity depends on several factors including machine power, the manner of operation and the amount of time the equipment is operated over a given time period.
Estimation of Construction Noise: The recommended method for predicting construction noise impact
for major urban transit projects is similar to that suggested by the Federal Highway Administration (FHA)13. The FHA prediction method is used to estimate the construction noise levels associated with the construction of a highway. The following equation is used to estimate the construction noise by phase14.
Where:
ML = Typical single equipment maximum noise level at 50 feet in dBA.
D = Distance from the equipment to the noise-sensitive location, in feet. (5) The construction phase’s one-hour LeqEquipment was calculated at the sensitive receptor location for each
item of potentially noisy equipment using the following equation14:
(6)
σ
Κ
+
=
eq npL
L
Where:
ML = Typical single equipment maximum noise level (Lmax) at 50 feet (or 15meters), in dBA.
D = Shortest distance (feet) from the equipment type to the nearest noise-sensitive location, or if a more sensitive receptor is further away, to the noise-sensitive receptor with the greatest impact.
N = Maximum number of the same equipment type operating hourly on the project during the construction phase.
HP = "Hourly percentage," expressed as the greatest nominal percent of time that the equipment is operated under load at the project site. This factor is based on EPA values or is estimated based on past experience with similar projects. Thus, the effective usage factor is (EUF) = N x HP/100.
Social Survey: A social survey was conducted among residents of the construction sites. Questionnaires
were administered to 30 persons residing in each of the study locations where construction activities were taking place (who are major sensitive-receptors). A total of ten questions were posed and tailored towards four areas of concern as follows:
(1) Age of respondents and period lived at present resident. (2) Identification sources of noise in the area.
(3) Residents’ perceptions and views on noise pollution from construction activities. (4) Respondents noise sensitivity rate and conditions
A total of 90 questionnaires were served out of which 85 (representing 94.4%) were completed and returned, which form the basis of the social survey analysis.
RESULTS AND DISCUSSION
The field monitoring of Noise Study of selected construction sites along the East-West Highway of Port Harcourt was carried out and results presented as follows:
Figure 1 showed noise levels measured at the selected construction sites. Table 2 showed computed
Average noise level, Lav, Equivalent Continuous Equal Energy level, Leq, and Maximum Noise Levels, Lmax, for study locations. These are plotted as shown in Figure 2.
Figure 1: Noise levels monitored at study locations
0 20 40 60 80 100 1 2 3 4 5 6 7 8 9 10
Nkolu Construction Site
Rukpakwulushi Construction Site Eleme Junction Construction Site
Table 2: Maximum Noise Levels Lmax, computed Average noise level, Lav, Equivalent
Continuous Equal Energy level, Leq, and Noise Pollution Levels, Lnp, for study locations
Figure 2: Maximum Noise Levels Lmax, Average noise level, Lav, Equivalent Continuous Equal Energy
level, Leq, and Noise Pollution Levels, Lnp, for study locations in comparison with FMEnv standard
Construction Noise Impact Assessment Analysis: Noise impact assessment analysis in this study was
carried out in two phases. The first phase was done using results of field measurement to determine and compute the average noise levels, Lav, equivalent continuous equal energy levels Leq, and noise pollution levels for each study location. The second phase of the analysis was performed to estimate the daytime equipment maximum noise levels LMaxEquipment and one-hour equipment energy average levels, LeqEquipment,
noise levels expected at the noise-sensitive location, based on the typical maximum equipment noise levels listed in Advanced Engineering Acoustics14. The calculations were made for the equipment (Trucks, Graders, Loader, Compactors, and Excavators)which were active at the construction sites where construction noise will result in the greatest noise impact on sensitive receptors.
Estimation/Prediction of Equipment Construction Noise: Construction noise is characterized by the
combined duty cycle and resulting noise emission of each piece of equipment. The duty cycle is
75 80 85 90 95 100 105 Nkpolu
construction site construction siteRukpakwulushi construction siteEleme junction
No ise Le ve ls (d B A ) Location Lav Leq Lnp Lmax FMEnv Location Lmax (dB) Lav (dB) Leq (dB) Lnp (dB) Exceedance Factor Standard deviation
Nkpolu construction site 93.4 89.88 91.08 100.11 1.01 ±1.9
Rukpakwulushi construction site 93.6 88.99 90.49 99.52 1.00 ±3.1 Eleme junction construction site 91.4 84.04 86.42 95.45 0.96 ±4.8
expressed in terms of the "usage factor" of the equipment, which is the percentage of time during the work period that the equipment is operating under load or at near full power14. In addition to the minute-by-minute variations in noise producing activities, construction projects are carried out in several different phases. Input parameters for the estimation of equipment construction noise at receptors’ locations are given in Table 3. Only those equipment which were active at each construction site during field survey are considered in this analysis as shown in Table 3.
Table 3: Input parameters for estimation of Equipment Construction noise
S/N Equipment item Number Active at a Time Working Hours per Day Net Operating hour per item
Equipment Utilization Factor Noise Level at 50 Feet (dBA) 1 Loader 1 8 6 0.75 85 2 Truck 4 8 4 0.5 88 3 Compactor 1 8 2 0.25 82 4 Grader 2 8 4 0.5 85 5 Excavator 1 8 6 0.75 87
Table 4: Estimated or Predicted Lmax of Construction Equipment at receptors Locations
Predicted LmaxEquipment (dB)
Distance
(meter) Truck Grader Loader Compactor Excavator
6.5 95.26 92.26 92.26 89.26 94.26 9.8 91.70 88.70 88.70 85.70 90.70 4.93 97.66 94.66 94.66 91.66 96.66 5.4 96.87 93.87 93.87 90.87 95.87 7.4 94.14 91.14 91.14 88.14 93.14 6.6 95.13 92.13 92.13 89.13 94.13 4 99.48 96.48 96.48 93.48 98.48 5.3 97.04 94.04 94.04 91.04 96.04 5.6 96.56 93.56 93.56 90.56 95.56 5.4 96.87 93.87 93.87 90.87 95.87
Table 5: Estimated or Predicted Leq Construction Equipment at receptors’ locations
Predicted LeqEquipment (dB) Distance
(meter) Truck Grader Loader Compactor Excavator
6.5 98.27 92.26 91.01 83.24 93.01 9.8 94.71 88.70 87.45 79.68 89.45 4.93 100.68 94.66 93.42 85.64 95.42 5.4 99.88 93.87 92.62 84.85 94.62 7.4 97.15 91.14 89.89 82.12 91.89 6.6 98.14 92.13 90.88 83.11 92.88 4 102.49 96.48 95.23 87.46 97.23 5.3 100.05 94.04 92.79 85.02 94.79 5.6 99.57 93.56 92.31 84.54 94.31 5.4 99.88 93.87 92.62 84.85 94.62
Figure 3: Variation of Measured Noise levels and Estimated/Predicted Lmax of Construction Equipment
as a function of receptors’ distance
75 80 85 90 95 100 105 4 4.93 5.3 5.4 5.4 5.6 6.5 6.6 7.4 9.8 No ise Le ve ls (d B A )
Receptor Distance (meter)
Measured Noise Levels Truck Calculated Lmax Grader Calculated Lmax Loader Calculated Lmax Compactor Calculated Lmax Excavator Calculated Lmax
Figure 4: Variation of Measured Noise levels and Estimated/predicted Leq Construction Equipment as a
function of receptors’ distance
DISCUSSION
Field results during monitoring exercise show that noise levels at Nkpolu construction site ranged in values from 87.4dB to 93.4dB with mean deviation of 89.9±1.9dB and maximum noise level of 93.4dB. Measured noise levels Rukpakwulushi construction site ranged from 84.7dB to 93.6dB with mean deviation of 88.99±3.1dB and maximum value of 93.6dB; also, field measurement shows that noise levels at Eleme junction construction site ranged in values from 75.0dB to 91.4dB with mean deviation of 84.04dB±4.8dB and maximum noise level of 91.4dB. These values exceeded stipulated FMEnv exposure limit 40% of the monitoring time at Nkoplu site, 30% of monitoring time at Rukpakwulushi site and 10% of monitoring time at Eleme junction construction site.
Computed equivalent continuous equal energy level, Leqfor each study location shows that Nkpolusite
hasLeq of 91.08dB, Rukpakwulushi has Leq of 90.49dB; while Eleme junction site has Leq of 86.42dB. Also, computed noise pollution levels, Lnp,for each study locations shows that Nkpolu construction site has Lnp of 100.1dB; Rukpakwulusi site has Lnp of 99.52dB; while Eleme junction site has Lnp of 95.45dB. The exceedance factors for each location then computed and result shows that Nkpolu site has exceedance factor of 1.01; Rukpakwulusi site has exceedance factor of 1.00; while Eleme junction site has exceedance factor of 0.96. These are classified as Moderate to High pollution on a rating scale [13], thus, the three selected study locations experience moderate to high noise pollution during period of the construction of the East-West Highway. This may cause hearing impairment of residents and may also results in some psychological effect on the people living or doing business around the areas. This was observed during questionnaire analysis and oral interviews conducted among the residents as well as those doing business in the study areas as 11.1% says they use earmuff whenever construction activity is going on (see Figure 7).
0 20 40 60 80 100 120 4 4.93 5.3 5.4 5.4 5.6 6.5 6.6 7.4 9.8 No ise Le ve ls (d B A )
Receptor Distance (meter)
Truck calculated Leq Grader calculated Leq Loader calculated Leq Compactor calculated Leq Excavator calculated Leq Measured Noise Levels
The equipment maximum noise levels, LMaxEquipment and one-hour equipment energy average levels,
LeqEquipment, expected at the noise-sensitive location were estimated using Federal Highway
Administration (FHA) construction noise prediction model13 of Equations (5) and (6) respectively. Results obtained compared favorably with measured noise levels at residents’ locations with about 94% accuracy and a range of 5% error. Variations of measured noise levels and predicted LmaxEquipment and
LeqEquipment Construction Equipment with distance as shown in Figures 3 and 4. Analysis shows that
estimated maximum equipment noise and one-hour equipment energy average noise levels at residents homes are high for all equipment observed at the sites except for compactor. This can cause people to be irritated and stressed and can interrupt their ability to sleep, which may lead to higher blood pressure, anxiety, and feelings of animosity toward other people.
Loud noise from construction activities can create situations where people cannot effectively communicate. These situations may cause annoyance or inconvenience residents in certain situations, and thus, could be construed as a safety issue if such noise prevents people from hearing important local noises such as approaching traffic, emergency warning devices, and alerts from other people. Some of these effects may not be permanent as construction noise is always temporary and site-specific depending on the duration of the construction activity. However, cumulative effects could be experienced by residents over time due other construction activities taking place within their environment or immediate vicinity.
Social Survey Analysis: The first area of concern examined the issue of age bracket of residents and
those who do business around the construction sites. Among the many effects of noise pollution is that of accelerated pres by cous is process or impairment of hearing acuity with age8. Result showed that about 33.3% of the respondents are 30 years and below, thus could be experiencing the effect of presbycousis process due to exposure to high construction noise. Social survey showed that construction equipment constitutes 64.1% of the overall noise in the resident environment, which 93.7% of residents said is very noisy. The results of attitudinal surveys, conducted to find percentages of people who express various degrees of annoyance are presented in Figures 5 and 6.
Figure 5: Noise sensitivity rate of respondents
9.30% 60.80% 15.80% 14.10% Manageable Annoying Very Annoying Extremely Annoying
Figure 6: Noise sensitivity of conditions respondents
Residents’ perceptions and views on noise from construction activities indicated that 81.4% of residents are disturbed by noise levels from the construction sites. Result of social survey further revealed that 76.6% are annoyed while 14.1% are highly annoyed. The noise sensitivity rate and tolerance level of residents showed that 77.8% has not gone for ear checkup, while 22.2% has gone for ear checkup. These results showed that majority of residents of the study areas are exposed to high noise levels and thus may be at risk of physiological and psychological health effects of noise. Overall social survey result showed that appreciable number of people residing around the study locations are sensitive to the noise pollution from construction activities within their vicinity. Some residents have already developed hearing difficulties of varying degrees as well as physiological and psychological health effects. Sleep disturbance and speech interference are major sources of annoyance among residents. This is evident in the tolerance levels response by residents of the area as shown in Figures 5 and 6.
CONCLUSION
The evaluation of construction noise levels at selected highway road construction sites in Port Harcourt and its effects on residential environment has been carried out. The following conclusions are drawn based on results of field measurements, data analysis and evaluation:
Monitoring results showed that all three construction sites have maximum noise values exceeded stipulated exposure limits 40% of the monitoring time at Nkoplu site, 30% of monitoring time at Rukpakwulushi site and 10% of monitoring time at Eleme junction construction site. This may pose a cautionary risk of hearing impairment of local residents. About 94 % of the predicted values of the noise levels using the Federal Highway Administration (FHA) construction noise prediction model were close to the measured values with a range of 5% error. Study showed that predicted maximum equipment noise and one-hour equipment energy average noise levels at residents homes are high for all equipment observed at the sites except for compactor
55.60% 25.80% 18.60% Disturbing Very Disturbing Indifferent
The study revealed that residents’ environment experienced moderate to high noise pollution during period of construction which may result in psychological effects, physiological health effects such as hearing impairment on residents and those doing business around the construction sites. The social survey further reveals that residents of the construction sites are inconvenienced and highly annoyed by loud noise resulting in high degree of sleep disturbance, communication interruptions among residents. Thus the residents may be at risk of psychological health effects of irritation and stress, which may lead to higher blood pressure, anxiety, and feelings of animosity toward other people.
RECOMMENDATION
The following mitigation measures are recommended against negative impacts during the construction activities.
Construction equipment should be insulated for noise and vibration which will ensure compliance with regulatory Standards. Proper inspection and maintenance of construction equipment should be carried out to reduce noise emissions. Adequate Mufflers or Sound Dissipative Devices should be provided on all machineries involved in construction activities. Noisy and stationary equipment should be enclosed in acoustic structure to reduce on site noise. If required, machinery producing high noise such as excavators should be provided with noise shields, use of noise suppressors or mufflers for heavy equipment. . Physical barriers in the form of walls and screens should be erected around each construction site to attenuate noise during construction. Noise levels at the site and the nearest or closest residential area should be monitored during construction period.
ACKNOWLEDGEMENT
The authors wish to acknowledge the Dean, Head of Department and entire staff of the Department of Environmental Engineering, Faculty of Infrastructural System Engineering, College of Engineering, and University of Port Harcourt, Nigeria.
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Corresponding author:
Ugbebor J. N.
1
Department of Environmental Engineering, Faculty of Infrastructure System Engineering, University of Port Harcourt, Nigeria
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