LIMNOLOGY RESEARCH UNIT
RIVER JUCAR
HYDROGRAPHIC AUTHORITY
"SINGULAR AGREEMENT FOR RESEARCH, STUDY AND
CONTROL FOR INITIAL DESCRIPTION AND SPECIAL
QUALITY MONITORING OF RIVER SECTIONS UNDER
CERTAIN BIOLOGICAL TREATMENTS UNDER THE RIVER
JUCAR HYDROGRAPHIC AUTHORITY”
Preliminary Report of the First and Second
Sampling campaigns
Among the selected variables for characterisation of sediment quality it have been chosen
those related to soil organic matter and sediment volume change as the most representative
to make a preliminary assessment of the response of treated riverbeds with enhanced
biological treatments for the regeneration of degraded river sediments. This includes the
results of the analyses of the sediment to determine its chemical oxygen demand (COD),
biochemical oxygen demand (BOD5), volatile organic matter (LOI) and percentage
reduction of sediment volume . It is performed as a comparative measure of the evaluation
of these parameters defining sediment changes resulting from the treatment application.
Samples will be taken before and after treatment is applied. The treatment will be
conducted between May and June 2002, and the post-treatment samples will be taken two
months after (September- October 2002). There will be samples taken from the treated zone
before and after, from a near area of similar characteristics and not treated –as control- and
from a distant and not contaminated area of the river –as reference values-.
For each of the six study areas the following sampling and numbers of samples were taken
in each campaign:
Treatment area: 9 samples of sediment.
Immediate upstream zone to the treatment area (control): 3 samples.
Non polluted area (reference of good quality): 3 samples.
There was a great heterogeneity of sediments detected in the analyses carried out in the preselection phase. For that reason it has become necessary to significantly increase the
number of sediment samples taken at each point in relation with original plans;, so that the
high variability was compensated with higher number of samples to achieve statistical
reliability of the results. Thus, the number of sediment samples, which was initially planned
to be 3 (2 at the point of application and 1 at the reference point) has become 12 in the
above two points and adding 3 more samples corresponding to the control point (no treated
point) situated upstream. In total 15 samples per area were taken. In this respect we can say
that the high heterogeneity of the studied sediments advise to maintain this number of
samples or even increase it in the treated area. Similarly, future studies would need to
increase to 6 or even 12 the number of samples taken from the untreated adjacent area
(control) and 6 samples in uncontaminated reference area, which is usually more
homogeneous. All of that conditioned by the size of the study areas.
The values of the selected parameters, although not definitive, are shown as comparison
charts on the following pages and are considered well related to the organic matter in the
sediments. The figure in the graph corresponds to the mean figures and standard deviations
obtained and each of the bars in the histogram refers to samples taken prior to treatment and
samples taken two months after treatment.
River Valdemembra. Location: Tarazona de la Mancha.
Estimating power reduction of sediment: 35-40%
BRIEF DESCRIPTION AND DISCUSSION OF THE RESULTS OBTAINED
This is an area with a high load of organic matter in the sediment due to urban discharges
has historically received from the town of Tarazona de la Mancha. These contributions
affect a river with moderated flow. Analyses indicate a reduction of the load of organic
matter in sediments at the treated zone around 40-60 % after about two months of the
implementation of the enhanced biological treatment, which together with a significant
reduction of the total volume of sediment can assess the application action as very positive
in improving the quality of riverbed in the treated section. However, during a recent visit it
was found that wastewater from Tarazona de la Mancha were being dumped directly into
the River Valdemembra, representing new contributions of organic matter that could
jeopardise the progress of treatment, or at least, alter our follow up planning. If that were
the case this would be detected in later samples when significant variations are present in
the samples taken from the upstream control (untreated) point.
River Magro. Location: Utiel WWTP.
Estimating power reduction of sediment: 25-30%
BRIEF DESCRIPTION AND DISCUSSION OF THE RESULTS OBTAINED
In the area here treated sediments have high organic matter content. Although apparently
could be considered that there is no significant decrease in the organic content of the
sediments in this zone in the treated area, the analyses performed on the untreated area
(control) show that this stretch of the river has suffered, in the period after the application
of treatment an important contribution of organic matter that has almost doubled the
organic content of the surface area of the sediment compare to the pre-treatment time.. This
has been shown in surveys and visits made to the area, detected mainly from contributions
of the sewage poured by Utiel WWTP, consisting of sludge from biological treatment and
other suspended materials. It has produced in the dumping area a layer of sediment of about
10 cm. Almost all of it consists of organic matter and other contributions from unidentified
sources on both margins of the treated area. Furthermore, despite the new waste disposal,
the sediments power reduction has been considerable (comparing,. for example in figures C
and D). Thus, maintenance of organic loads that has been measured in the treated area does
not denote the inaction of the treatments, but the good effect of the treatment that served to
prevent increasing the organic load and the power of the sediment as a result of such
discharges, occurred in the area (see increase of organic matter in control point). Thus, also
in this area the enhanced bioremediation treatment can be considered as effective, although
the continuous discharge of organic matter may counteract its effect. If the elimination of
untreated discharges is not guaranteed or controlled the effect of the treatment will not
solve the pollution problem, although will diminish it. This brings us to one of the
necessary preconditions for applying this type of treatment: the quality of the circulating
water must be improved and permanently stable before treatment is applied, as if otherwise
the positive effect of the treatments on sediment quality is reduced or annulled by further
releases.
River Magro. Location: San Antonio de Requena.
The treated area is next to the town of San Antonio de Requena, where it comes, in addition
to River Magro water, water from a small canal, which receives the discharge of the
bottling purification plant called "San Benedetto".
Dates of application and sampling.
First sample: 05/02/28
Application: 02.07.27
Second sample: 10/08/02
Incidents.
No incidents of interest were observed. It is noteworthy that the bottling treatment plant
San Benedetto worked correctly on the dates that the area was visited.
Estimation of sediment power reduction 30-35%.
BRIEF DESCRIPTION AND DISCUSSION OF THE RESULTS OBTAINED
This stretch had a high load of organic matter in sediments. Here the positive treatment
effect seems clear, since the organic loads in the treated areas have been reduced to onethird (60-70% less) after two months of treatment application. Furthermore, the power of
the sediment also has experienced a decline of about 25%. In this case we have not detected
inputs of pollutants, so that the results appear to reflect directly the action of the product.
River Cañoles. Locatión: Vallada weir.
The treatment site is downstream of Vallada town.
Dates of application and sampling.
First sample: 25/06/02
Application: 30/07/02
Second sample: 29/10/02
Incidents.
No incidents of interest were observed.
Estimation of sediment power reduction: 45-50%
BRIEF DESCRIPTION AND DISCUSSION OF THE RESULTS OBTAINED
Among the six river sections selected for this pilot study this is the one with lowest organic
matter content. The results of the tests carried out do not denote a significant decrease in
the levels of organic matter in the sediment after treatment application, since the values
found before application are statistically similar to those obtained two months after it.
However, it has been noted a considerable reduction in the strength of the thickness of the
layer of sediment, which is reduced to about half. These results do not clarify the treatment
effect in this area, so we refer to subsequent sampling campaigns in order to obtain results
that may confirm and explain this behaviour. Nevertheless, compared to sections with high
loads, it seems that in those the effect of treatment on the recovery of sediment quality was
much faster and more evident, allowing us to see that such treatments are especially
effective in reducing the organic load when it is high.
River Albaida. Location: Albaida (Previous WWTP.).
Estimation of sediment power reduction: 40%.
The decrease in power is obvious but difficult to estimate its relationship with the treatment
effect due to movement of sediment because of sudden raise of river flow that occurred in
this area at the time.
BRIEF DESCRIPTION AND DISCUSSION OF THE RESULTS OBTAINED
Although the analyses indicate that the organic charge remain after treatment, the results in
this area are difficult to evaluate because the sediment of the treated area was partially
washed away by a flood that brought the area a lot of plant debris and altered the area in
which the application was made of the enhanced biological treatment. Therefore results of
the second sampling campaign carried out following the flow raise cannot be considered
significant, since the application of bioremediation treatment preceded that event.
Vinalopó River. WEIR Benejama
Estimating power reduction of sediment: 25-30%
BRIEF DESCRIPTION AND DISCUSSION OF THE RESULTS OBTAINED
The results obtained, so far, in this section do not demonstrate an important reduction in
organic matter content in the treated sediment, although somewhat reduced power and
changed the look of the sediment has been noticed. As a distinguishing feature of this
section from the rest ones tested we may say that organic load is due mainly to cellulosic
waste discharges from paper mills. This type of organic matter involves only a carbon
source but not other potentially necessary nutrients for the growth of microbial inoculum
contained in the product applied. Although together with the microbial inoculums,
cellulolytic enzymes were added, and even nutrients for the bacteria could be added, such
addition of nutrients may not be enough to sustain microbial growth as to allow the
complete degradation of contaminant cellulosic material and also the amount of added more
detail. This, if confirmed, would highlight the need to modify the composition and
conditions of inoculation of the product to meet special organic waste such as cellulose,
beyond the initial modifications already included by the supplier of the product.
We can say that this type of sediment requires "special" treatments, and merits a specific
pilot study in each case prior to the extensive application of the treatment to design the
appropriate composition of the enhanced biological treatment to be effective.
PRELIMINARY CONCLUSIONS AND COMMENTS
Partial results to date show that the application of enhanced biological treatments to
improve degraded riverine sediments is particularly effective in reducing the organic load
and the power of the sediments in those sections where the organic load is high and highly
biodegradable, such as those that have suffered from urban waste water discharges or
agricultural and food industries. Although there are no measures -as contained in the
relevant field workbook-, the sampling staff found a significant reduction in the
characteristic odour in these sections. These initial results should be confirmed by the
samples taken according to the initial protocol of the pilot study in the coming months to
June 2003, nearly a year after treatment application, as well as other analytical parameters
samples already taken or to be taken, which is a multiplication by five of the initially
planned analytical samples.
The contributions of new pollutant discharges take stretches right back to the old conditions
of degradation prior to the treatment. This means that while the treatments shown to be
effective in restoring river sediments, causing minimal disturbance to the natural
environment, its use must be accompanied by a strict adherence to the quality of the
circulating water. That is why, with the reservations of been preliminary results, we
recommend this type of treatment for the restoration of river sections where previously
appropriate purification procedures for discharges have been adopted. If no further
pollution is discharged to the river there is reasonable assurance that the improvement in
water quality that we have achieved by our treatment over the degraded sediment regardless the conditions that historically generated them- is stable and will be maintained
over time
The study reported here is still under development, since the last sampling campaign is
planned for the months of May and June 2003, due to the one-year lag between the start of
the study and application of the product. There is, therefore, a lot of information to obtain,
both on the results in the sections tested and on the refinement of the methodological
aspects in the selection of the most appropriate parameters for monitoring the effectiveness
of testing and other aspects of control quality, and the development of the overall results.
However, all the above supports the planning of new actions for the recovery of river
sections selected, according to the main characteristics that we believe are required,
namely:
- Improved Water Quality compared to the quality during the periods in which the
contamination of the riverbed occurred and sufficient guarantees to maintain that quality
over time.
- High organic content in the sediments to be treated.
- High biodegradability of organic matter accumulated.
- Some hydrodynamic stability of the sedimentary bed.
-Standardisation of conditions of application depending on the characteristics of the section
to be treated, especially in the sections that we have considered as "special", for which a
specific pilot study would be required to adjust the composition of the product to conditions
of these special sedimentary beds.
Additionally we emphasize the following:
1) The need to continue monitoring the treated areas until next June for clear and definitive
results as to the types of sediment and conditions for which treatment is effective not only
in terms of reducing the organic load but also considering other aspects related to pollution
such as chemical and biological indicators.
2) Set the parameters most suitable as indicators of the evolution of the treated sediment
and improving its quality. Since it has been also analysed other parameters not shown in
this report, the overall results at the end of the study treatment will define whether these are
suitable or if any can be added or replace with advantage to theses ones now presented.
3) In view of the complexity of the study of sediments as evidenced in this pilot study, it is
recommended that the follow up and control of treatments of similar experiences to be
carried out by qualified personnel with experience in this type of action.
4) The pilot study in the selected points is, in our opinion, a preliminary test that could be
supplemented with some additional test, rather than involve one or two isolated points on several
rivers, should focus on larger sections of one or two rivers at the most, attending for selection to the
above conditions and seeking in this second phase that the size of the riverbed selected to be
manageable for the purposes of research and quality control.
In the field of River Jucar Hydrographic Authority CHJ, two of the riverbeds that seem
most appropriate due to its characteristics and size are River Valdemembra and River
Magro. The carry out a performance in broader stretches of these rivers -which may be
contiguous or not- they should be at this time free of present continuous discharge of
pollutants. It would allow us to improve the level of knowledge of the mechanisms and
conditions that determine the effectiveness of these Bioremediation treatments. We also
would obtain information on whether or not the application of treatment in a given area
influences untreated sediment in areas located downstream from the treated site. This will
also allow us to apply the results to the concept of "River Continuum" (Vannote et al.
1980).
As to the indicative timetable for further action could be:
- Characterisation of river sections, suitable for a Bioremediation performance at medium
scale, to carry out from the spring of 2003. This characterisation of the sediments to be
treated and the most suitable river stretches should be carried out by trained staff integrated
into a research group with expertise in this type of analytical guidelines and interpretation
of the available results.
- After the characterisation of the river stretches and after deciding the most suitable areas,
the application of bioremediation treatment could begin in the spring of 2004, ensuring that
the application is not delayed so to obtain maximum effectiveness, facilitated by increased
summer temperature in these sections located at approximate 600-700 m (asl) altitudes.
Consistent with the above we propose three levels in the work of monitoring and control of
such Bioremediation actions:
a) First stage:
Pilot project, which is undertaking now. We propose to complete it prolonging it until the
last sampling in the month of June, joint development of the results and writing the final
report in October 2003, so that we request the extension of the present agreement to that
date.
Its basic objectives are:
- Development of the analytical and sampling methodology.
- Training of staff to carry out the monitoring.
- Assessment of the effectiveness of treatment and the intrinsic and extrinsic factors
affecting it.
- Selection of parameters that best characterise the changes taking place in the sediment and
therefore, appropriate for monitoring the effectiveness of the process and interpretation of
the results obtained in each case.
b) Second stage:
Characterization of more or less continuous or even connected river stretches, in rivers of a
manageable size and flow for the purpose of experimentation for research. These are the
best characteristics of the segments of the river to allow studying the effects of the
bioremediation treatment in a long enough area of a riverbed to allow the application of
models based on the above mentioned concept of "River Continuum".
This phase should also establish basic and reliable analytical protocols, specifically
mentioning the appropriate parameters as indicators of the quality of the process and some
general guidelines for the interpretation of the results obtained from this type of action.
c) Third stage:
Following completion of the above two steps, it must be obtained:
1 - A general protocol that allows decision making regarding the timing of these
Bioremediation treatments, the extent of the area to be treated, correct place within the
riverbed places and all other conditions for a reasonable assurance of success.
2 - Availability of analytical protocols for the standardisation of riverbeds characterisation,
monitoring and quality control of treatments and general guidelines for the interpretation of
the results related to this type of action.
The characterisation of the riverbeds allows financial valuation of implementation of the
relevant corrective treatment project using these Bioremediation techniques.
In Valencia to February the 4th, 2003
Signed. Antonio Camacho-Gonzalez
Work of control coordinator.
Signed. Eduardo Vicente-Pedros
UVEG team coordinator.