Good Law ProjectTom from @[email protected] is concerned “immediate threat” that these discharges by water companies pose to his business and marine life.
More about Tom’s part in our case here 👇
https://glplive.org/rho-visit-tw
stevebungay@goodlawproject I thought I’d reply as I have reasonable experience in disputes of this nature.
It’s an emotive dispute, but the courts won’t let this usurp the science, or the law.
As it stands, I would anticipate that it would be thrown out before it even gets to court. The language and direction is critical. Don’t shoot the messenger, but it would be easy for me to argue the case that ‘dumping sewage’ would not have an ‘immediate effect’ on the viability of oyster farming.
1/N
It’s an emotive dispute, but the courts won’t let this usurp the science, or the law.
As it stands, I would anticipate that it would be thrown out before it even gets to court. The language and direction is critical. Don’t shoot the messenger, but it would be easy for me to argue the case that ‘dumping sewage’ would not have an ‘immediate effect’ on the viability of oyster farming.
1/N
@goodlawproject
First you have to consider that oysters are filter feeders. They feed on coarse particulate organic matter (CPOM). This CPOM could be algae, it could be plankton, and although seeming unpalatable, yes, it could be sewage, especially diluted sewage. Sewage will actually be a good nutritional food source for oysters.
2/N
First you have to consider that oysters are filter feeders. They feed on coarse particulate organic matter (CPOM). This CPOM could be algae, it could be plankton, and although seeming unpalatable, yes, it could be sewage, especially diluted sewage. Sewage will actually be a good nutritional food source for oysters.
2/N
@goodlawproject
In my student days I surveyed Portobello beach when Southern Water were still discharging screened raw sewage from Brighton via a short sea outfall.
The ecology of the beach was diverse, and the beach was covered in mussels.
Years later, I repeated the survey, after Southern Water had installed a long sea outfall.
The mussels had gone. Without the sewage as the primary food source for the filter feeders, the population of mussels had gone.
3/N
In my student days I surveyed Portobello beach when Southern Water were still discharging screened raw sewage from Brighton via a short sea outfall.
The ecology of the beach was diverse, and the beach was covered in mussels.
Years later, I repeated the survey, after Southern Water had installed a long sea outfall.
The mussels had gone. Without the sewage as the primary food source for the filter feeders, the population of mussels had gone.
3/N
@goodlawproject
‘Dumping sewage’ is disingenuous. The water companies will have environmental permits that allow them to discharge treated and partially treated sewage under certain circumstances.
We have inherited a system of combined sewers, which allow both sewage and surface water and rainfall to combine. This facilitates massive fluctuations in the flow conveyed in sewers.
As a consequence wastewater treatment works have to be designed to cope with these fluctuations.
4/N
‘Dumping sewage’ is disingenuous. The water companies will have environmental permits that allow them to discharge treated and partially treated sewage under certain circumstances.
We have inherited a system of combined sewers, which allow both sewage and surface water and rainfall to combine. This facilitates massive fluctuations in the flow conveyed in sewers.
As a consequence wastewater treatment works have to be designed to cope with these fluctuations.
4/N
@goodlawproject
Let’s briefly consider hospitals as an analogy. Hospitals are designed with no peaking factors. They are designed for average demand. In winter, when the demand goes above the average, the system fails.
Considering wastewater treatment works, they are designed on multiples of the average sewer flows. Typically they are designed to treat peaks of 6 to 9 times the average flow. If the flow remains below this, no one is the wiser.
5/N
Let’s briefly consider hospitals as an analogy. Hospitals are designed with no peaking factors. They are designed for average demand. In winter, when the demand goes above the average, the system fails.
Considering wastewater treatment works, they are designed on multiples of the average sewer flows. Typically they are designed to treat peaks of 6 to 9 times the average flow. If the flow remains below this, no one is the wiser.
5/N
@goodlawproject
This peaking factor is historically based on sediment flow in rivers during times of high rainfall.
If the sewage is diluted by 6 to 9 times, the sediment in the sewage would be equivalent to the natural sediment flow in rivers, and no long term harm would be done to the river.
This logic gave rise to discharge consents for minimum flow to full treatment (FFT), flow to storm treatment, and maximum flow to works (MFFT).
6/N
This peaking factor is historically based on sediment flow in rivers during times of high rainfall.
If the sewage is diluted by 6 to 9 times, the sediment in the sewage would be equivalent to the natural sediment flow in rivers, and no long term harm would be done to the river.
This logic gave rise to discharge consents for minimum flow to full treatment (FFT), flow to storm treatment, and maximum flow to works (MFFT).
6/N
@goodlawproject
1. FFT is roughly equivalent of 3 times the average flow.
2. Flow to storm treatment (screening and settlement) is equivalent to flows between 3 and 6 times the average flow.
3. MFFT is broadly equivalent to 6 times the average flow. This typically known as a Formula A overflow, and the flows after screening (6mm in two directions) are allowed to bypass the treatment plant.
Water companies must not prematurely discharge to storm tanks or bypass the works.
7/N
1. FFT is roughly equivalent of 3 times the average flow.
2. Flow to storm treatment (screening and settlement) is equivalent to flows between 3 and 6 times the average flow.
3. MFFT is broadly equivalent to 6 times the average flow. This typically known as a Formula A overflow, and the flows after screening (6mm in two directions) are allowed to bypass the treatment plant.
Water companies must not prematurely discharge to storm tanks or bypass the works.
7/N
@goodlawproject
Problems have arisen as the multiple of ‘9’ got lost somewhere along the line. So flows conveyed to the plants exceed their storm treatment capacity.
If there are no premature 3DWF or Formula A spills, the Water Company will be acting within its legal requirements.
Fully treated sewage (3DWF) will mix with partially treated sewage (3 to 6 DWF) and it is very unlikely that the resultant blended effluent will pose a risk to filter feeders such as oysters.
8/N
Problems have arisen as the multiple of ‘9’ got lost somewhere along the line. So flows conveyed to the plants exceed their storm treatment capacity.
If there are no premature 3DWF or Formula A spills, the Water Company will be acting within its legal requirements.
Fully treated sewage (3DWF) will mix with partially treated sewage (3 to 6 DWF) and it is very unlikely that the resultant blended effluent will pose a risk to filter feeders such as oysters.
8/N
@goodlawproject
There are then the combined sewer overflows to consider.
Again, these probably (not always) are consented overflows, that are allowed to operate in exceptional circumstances.
Often the problem with the premature operation of these CSOs is that the associated treatment plant is not treating the consented maximum flow to works.
If this is the case, the water company will be at fault, and there will be a potential claim.
9/N
There are then the combined sewer overflows to consider.
Again, these probably (not always) are consented overflows, that are allowed to operate in exceptional circumstances.
Often the problem with the premature operation of these CSOs is that the associated treatment plant is not treating the consented maximum flow to works.
If this is the case, the water company will be at fault, and there will be a potential claim.
9/N
@goodlawproject
Going back to filter feeders, I would expect there to be a ‘cleansing’ stage after the harvesting of the mussels, i.e., a period where there oysters are stored in clean water to allow them to flush any embodied foodstuffs. However, I accept I am not an expert on oyster farming.
10/N
Going back to filter feeders, I would expect there to be a ‘cleansing’ stage after the harvesting of the mussels, i.e., a period where there oysters are stored in clean water to allow them to flush any embodied foodstuffs. However, I accept I am not an expert on oyster farming.
10/N
@goodlawproject
The two scenarios where the the legal discharge of sewage could impact on an oyster farm is:
1. Pathogens - organisms such as E.coli, F.coliforms, and salmonella spp.
2. Bioaccumulation of heavy metals. However, bioaccumulation is very unlikely.
11/N
The two scenarios where the the legal discharge of sewage could impact on an oyster farm is:
1. Pathogens - organisms such as E.coli, F.coliforms, and salmonella spp.
2. Bioaccumulation of heavy metals. However, bioaccumulation is very unlikely.
11/N
@goodlawproject
For there to be a case, you would have to demonstrate that premature overflows were occurring,
and/or
partially or untreated sewage is being discharged outside of the legal consented conditions, or that constituents (such as pathogens) in the sewage was having a detrimental affect on the oysters.
For there to be a case, you would have to demonstrate that premature overflows were occurring,
and/or
partially or untreated sewage is being discharged outside of the legal consented conditions, or that constituents (such as pathogens) in the sewage was having a detrimental affect on the oysters.
@goodlawproject
In my view the minimum flow to full treatment at the wastewater treatment plant will be pivotal.
This will also be very easy to demonstrate. The water companies have a legal duty to have MCERTS flowmeters recording the volume being treated.
END