Environmental Engineering Reference
In-Depth Information
The wet candle device, based on
[3]
, was selected for the G-Terra studies as a
sound methodology to determine the atmospheric chloride deposition rate. The
results for the salinity accumulation rates, with a weighted average of 74 mg/m
2
day, clearly show the presence of atmospheric salt at the A25 site.
The initial outcomes seem to confirm a high level of salinity, organic matter and
related parameters in the A25 highway runoff. It was also observed higher levels
for nitrogen and phosphorus, when compared to the 2003/2004 monitoring study.
The oil and grease concentrations showed a very high standard deviation (1.789
mg/L) and a minimum concentration below 0.184 mg/L. These results are not
understood yet, and future monitoring studies within the G-Terra project will
certainly help to comprehend the sources of oil and grease and their processes
within the road environment.
All the oil and grease samples concentrations are below the Portuguese law for
wastewater point discharges levels. However, concerning the SST, COD and BOD
5
concentrations, 35%, 14% and 3% of samples, respectively were above the discharge
limits of this law. This sort of knowledge is relevant for the establishment of guidelines
for road runoff pollution management, the final objective of G-Terra project.
These results are still being analyzed. It is believed that the adopted methodolo-
gies are adequate to the study. These and the data from the three next monitoring
periods at the A25 site will provide enough data for simple and advanced statistical
analysis that will support the identification of the particular characteristics and
processes, concerning road runoff in coastal areas.
If the phenomena associated with the high salinity in highway runoff in coastal
areas are better understood and quantified, a new and valuable contribution to the
knowledge will provide information for highway runoff management in countries
like Portugal, with a significant coast line.
References
1. Albuquerque AM (2006) Study of the performance of the treatment pond of the highway A23
- Ligação à Covilhã. Master thesis dissertation (in Portuguese), Beira Interior University
2. Ambler HR, Bain AJ (1955) Corrosion of metals in the tropics. Journal of Applied Chemistry
5:437-467
3. American Society for Testing and Materials (ASTM) G 140-02 (2002) Standard test method
for determining atmospheric chloride deposition rate by wet candle method. Annual Book of
ASTM Standards, Philadelphia
4. American Water Works Association (2005) Standard Methods for Examination of Water and
Wastewater, 21st edn
5. Antunes PA, Barbosa AE (2005) Highway Runoff Characteristics in Coastal Areas - A case Study
in Aveiro, Portugal. Tenth International Conference on Urban Drainage, Copenhagen, 6 pp
6. Barbosa AE, Antunes PB (2004) Águas de Escorrência de Estradas Sistemas para Minimização
de Impactes, 2° Relatório, Relatório 128/04-NRE/DHA, Laboratório Nacional de Engenharia
Civil, 66 pp
7. Barbosa AE, Henriques MJ, Fernandes JN (2006) Quality of Highway Runoff in Coastal Areas:
Special Cases? Eigth Highway and Urban Environment Symposium, Nicosia, Cyprus, 10 pp
