Stormwater quality assessmentt

Storm water runoff is a major non-point source pollution (the photo attached indicates that transportation is the one of the major sources of pollution along roadside) in the aquatic environment.

 

Storm water runoff contains many types of contaminants such as
1. Suspended particles;
2. Heavy metals (mercury Hg, cadmium, Cd, lead Pb, chromium Cr, arsenic As, copper Cu, nickel Ni, and zinc Zn)
3. Nutrients (nitrogen N, phosphorus P, and sulphur Si)
4. Hydrocarbons
5. Herbicides
6. Pesticides

which may be a significant health hazard to humans and aquatic organisms because it is largely untreated. 

The quality of stormwater (the photo attached indicates that a fish dead in creek during the first event of stormwater runoff) needs to be monitored in order to evaluate whether concentrations of pollutants (organics and inorganics) exceed regulatory limits in storm water runoff. The information provide some important information on strategies for controlling the quality of storm water runoff.
 

 

There are three Major techniques are often used in storm water runoff monitoring program, which include:

1. Chromatography - Ion chromatography (IC), Gas chromatography (GC/MS) and High 
     pressure liquid chromatography (HPLC)

2. Spectroscopy - UV-visible Spectroscopy, Fluorescence Spectroscopy 

3. Atomic spectrometry: Atomic Adsorption Spectrometry(AAS) and Inductively Coupled
    Plasma-Mass Spectrometry (ICP/MS).

Storm water quality assessment objectives:

1. Design cost-effective sampling and analysis procedures capable of meeting regulatory l
   limits for all constituents
2. Conduct field testing of the procedures to identify constituents that may
    exceed regulatory limits at a specific place (e.g., highways roadside).

The diagram (red line EPA limit of criterion continuous concentration in saltwater, and white line is rain precipitation) shows the concentration levels  of dissolved Cu monitored at two different roadsides during the storm water run off events, where the metal exceed the EPA limits in the most storm water run off events. 

Toxicity of stormwater can be assessed using 

!. Fish, such as young trout as photo shown left

2. Algae

3. Water flea

Toxicity of sediment in adjacent aquatic environment can be assessed using bivalves, such as:

1. Clam, the clam Macoma (as photo attached);

2. Cockle

3. Mussel

4. Cray fish

5. Sediment dwelling worm
 

Enrichment Factor (EF):

           EF = (M/Al)sample/(M/Al)reference
Where:
(M/Al)s = the ratio of metal and Al concentrations of a sample,
(M/Al)r = the ratio of metal and Al concentrations of a reference sediment, where the sediment has little history of  metal pollution.

Correlation, as diagram left shown, between total EF values and clam survival (p<0.002) indicates poor quality of the sediment assessed.

Inter-element relationships of Fe-Ni and Fe-Pb in clam tissues. Function of the MT/T couple as a homeostatic metal system: An increase in the amount of available Zn, or probably Fe, induces the synthesis of T through the action of the metal, leading to the formation of MT. An increase in the amount of available Thionein results in a bioaccumulation of the metals in clam tissues and tolerance of the clam towards the metals.