We have set up a test field for highway stormwater monitoring on Rijeka city bypass as a start of our stormwater monitoring program. ADT on this bypass is between 15000 and 50000. We are in the process of creating our monitoring plan and I would appreciate if anyone could share their experiences in sampling, sample volume and which elements should be included in analysis.
Our test field is on an intersection with a closed, watertight drainage system and there are 3 small watersheds from which stormwater goes to an oil and grit separator. we plan to take samples form 5 locations - 1 from each watershed, 1 before and 1 after the separator.
Refer to
http://www.bmpdatabase.org/Docs/2009%20Stormwater%20BMP%20Monitoring%20Manual.pdf
this is most up to date and complete guide as to how to monitor for stromwater
Please contact Doug Heath at US EPA Region 1 - he is an expert at stormwater monitoring with extensive field experience - [email protected] or 617-918-1585.
Regards,
Alison Simcox, US EPA Region 1
The sample volumes and choice of sampling will largely depend on what parameters you're sampling for. In the US, it's common to sample highway stormwater for parameters including oil and grease, total suspended solids, TOC, and a number of metals, including copper, zinc and lead. Those will give you a general indicator of the quality of the stormwater, though you can of course go after a lot of other chemicals - though this is largely a function of your budget. The BMP database manual is pretty good. Here's another resource you might find useful: http://www.ilma-lakes.org/PDF/Fundamentals_full_manual_lowres.pdf
Isco samplers work well for water samples that can keep for a period of time. http://www.isco.com/products/products1.asp?PL=201
If you want to sample for nutrients or inorganic carbon, these probably need to be pre-poisoned with HgCl2 or other.
Thank You all for Your responses and advices.
I have the literature suggested, but still...
It is our objective to conduct monitoring for estimate pollution concentrations and loads. All basic parameters (TSS; pH, oil and grit, Cd, Cu, Ni, Pb...) will be monitored. But there is still a question what other parameters should be monitored.
Rijeka bypass runs thru karst area in which drinking water reserves for this area is located and pollution prevention is one of main concerns.
I would add Zn if you have Zn-covered material on your highway, as well as PAHs which are produced by vehicles: unfortunately the latter needs specific glass sampling vessels that need to be "burned" before use, as a final cleaning procedure. Thus 2 set of samplers may be necessary: one for major pollutants and trace metals, one for organic micro-pollutants.
You might want to test for toxicity after the separator. Upstream toxicity can probably be assumed by reference (unless you are looking to publish results in journal; if so will have most likely have to perform sample toxicity above as well). Use a suite (more than one type of) toxicity test. You may want to sample or filter for dissolved or mobile constituents and calculate potential toxicity for comparison to measured toxicity results.
Can i suggest looking on the University of Abertay UWTC website I know that that department has written a guidance document for all road agencies in the UK concerning storm water management and SUDs so if you are looking for some information i would have a look it could be beneficial.
http://sudsnet.abertay.ac.uk/
As your water discharges into a karstic region with anticipated small resources for driking water, the water will probably infiltrate into water bodies used for drinkin water production, I assume you will have to look for PAHs which are ususally oriinating from engine exhausts but even more from tyre wear off.
depending on the levels of heavy metals and hydrocarbons and PAHs different strategies to bring the quality up to drinking water standards can be applied. There have bee several EU projects adressing stormwater pollution and management.
Perhaps you could contact the NATIONAL SPELEOLOGICAL SOCIETY and see who is
monitoring ground water entering caves (Karst).
Be aware of the dynamics of stormwater flow volume and pollutant load with rain event progression, it should inform your sampling strategy. Most of the pollutants will come with the very first flush, ahead of peak flow. Pollutant concentrations will not track flow volume both would be needed to sum or integrate for total load.
You might also consider doing tests for TSS and Turbidity if the stormwater is collected from several surface run-offs originating from exposed ares without vegetative cover and are prone to all types of erosion.
Sampling for TSS will assist with determining sediment loads to identify potential sediment mobilizations sources
Zdeslav,
I see that you will be collecting samples for oil and grease, and suggest you analyze samples for TPH and at least pyrogenic PAHs. Ideally, one you like to sample before and after rainstorm events (at least 5 events total per location). Take a look at this reference for additional ideas on experimental designs: Guidance Manual for Monitoring Highway Runoff Water Quality, Report No. FHWA- EP-01-022. Federal Highway Administration, Office of Natural Environment (http://www.environment.fhwa.dot.gov/ecosystems/h2o_runoff/index.asp). Good luck!
I wuld like to suggest you for separation the density checkup of such a contaminated water upon heating on several occasion and collection of vapours and then condensation for maximum procuration.
The stormwater pollutants will be in two main phases, dissolved and particulate. It might be of interest to separate these due to their different mobility and toxicity. Thin film methods (DGT) might be used for monitoring dissolved metals, and SPMDs for micro-organics.
Are you considering modeling quantity and quality of highway storm water? Models are useful in scenario analysis and decision making.
Tell me about the design of the oil and grit separator. How does it work?
Is it a standardized device from a manufacturer, or is it something designed
specifically for you construction project.?
Dear Richard, it is generally assumed that most pollutants come with the first flush, but that is really very dependent on the situation. It is true in those cases were the pollutants are trapped in sewer sediments and are mobilised with the first increase of hydraulic load. It is not true in those cases were emissions are rain dependent like washing off from surfaces in those cases you may have the peak of the hydraulic load long before the peak of pollution. The same holds for sewer overflows of a bit more complex systems. It is after some thinking easily imaginable that pure rainwater is discharged for quite a while before polluted loads (of pure waste water) are being discharged. It is not only imaginable it also regulary happens ;-)
I think the point was mostly that the load and the flow is not always coincident. Your post provides an example different than mine but the solution is the same: you have to monitor concentrations of pollutants over the course of storm water flow events, not at a single point during a storm event, if one is to estimate total loading.
Don't forget ecotoxicological measures which are very useful in this context.
If you decide to use them, i recommand measures on soluble pollutants and on polluted particules
If you are concerned about possible threats to drinking water systems I suggest that you base your monitoring parameters around any regulatory limits that have been placed on your water supplies. This all boils down to what information you really need and what you can spend. TPH, PAH, and Oil and Grease should all be of concern, but they are tricky to monitor in karst areas. Sample collection timing is everything, and collecting one sample from each location for a storm event will not give you a true approximation of pollutant load.
- Badges
- Science topic