SISTEC Presentation July 3 2002

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Do SUDS Work? A Monitoring Overview at DEX
Chris Jefferies University of Abertay Dundee
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Presentation Content

• Overview of the DEX Monitoring Programme
• Hydrology and water quality
• Monitoring costs
• Observational monitoring
• Dissemination of outcomes
• Acknowledgements to Wilcon Homes Now Taylor
  Woodrow

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Monitoring was a Condition of Planning Consent

• SUDS were virtually unknown when DEX was planned
• Many questions about planning, design and
  operation had not even been asked, let alone
  answered.
• Clause in consent - main developer (Wilcon Homes)
  should monitor performance for five years May
  1999 April 2004
• UWTC bid for and won this work.
• Geek name Monitoring Urban Drainage Wilcon,
  Abertay Dundee, Edinburgh (MUDWADE)

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MUDWADE Rationale

• Financial justification Commuted sum of 90k
  per pond for 7 ponds sought by Fife Council for
  maintenance monitoring much cheaper. Once
  results available, then strength to negotiate!
• Flows and loads monitoring both longer term and
  event based.
• Sediment surveys (Kate Heal)
• Visual inspections, photographs, reporting
  problems
• Maintenance cost monitoring
• Initially the remit was to examine all SUDS on
  Duloch Park but by April 2004 this had reduced to
  3 ponds and 1 wetland

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SUDS Maintenance Investigations DEX - The Ponds
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Flows and loads monitoring

• Initially we wanted to monitor at 3 ponds and 2
  detention basins
• Pond 7 was control but development commenced very
  quickly.
• One of the detention basins outlet blocked for
  18 months.

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Catchments Under Investigation
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Water Quality
Monitoring results - Linburn Pond inflow TSS
Monitoring results - Linburn Pond outflow TSS
Pollutant Budget Very difficult due to number of
inflows and duration of study needed. What would
be the purpose?
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Water Quality
Question - How do you decide if these treatment
ponds are satisfactory?
Answers -
Hydraulics - Well established principles set by
flow criteria Water quality - What should be the
basis of the decision? What time frame should
be used? How do you view episodes of poor
quality? Do you use a two tier consenting
approach? Should the outflow be stream water
quality?
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Flow Model Calibration using PCSWMM

• A number of continuous rainfall runoff sets
  including flows, continuous sonde data and spot
  sampling
• Eyeball comparison of measured flows with
  modelled.

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Conclusion from flow quality monitoring

• Detention basin with appropriate flow controls
  could be a replacement for ponds if catchment
  hydrology is the only concern.
• Detention basins could replace the ponds and
  allow for extra development space if catchment
  hydrology is the only concern.
• The Water Quality Performance of these ponds is
  excellent and will probably remain so.
• However, water criteria for treatment ponds must
  be established.
• Modelling and evaluation of the Halbeath and
  Linburn pond catchments at Duloch Park is
  continuing

Thanks to Adolf Spitzer
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SUDS Maintenance Investigations

• Monitor / Visually Inspect regional systems at
  Duloch Park / DEX
• Document observed maintenance activities and
  system performance using simple tick sheets and
  photography
• Gather maintenance cost data from land based
  contractors

Thanks to Gaye McKissock Alison Duffy
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SUDS Maintenance Investigations

• MUDWADE Project Cost Data
• UWTC received copies of
• Detailed invoices from project manager
• Payment certificates from project manager
• Inspection sheets from contractor
• Fax outlining monthly breakdown in activities
  from contractor

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DEX Maintenance Activities
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Observational Monitoring

• Regular visits to catalogue changes with time
• Photographic evidence supported by measurements
• Concurrent development information.
• Tick sheets completed at each visit.
• Focus on Detention Basins here

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Linburn Pond (Kate Heal)
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Detention basins serve each site at DEX in
Dunfermline
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Detention Basins
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Basin D/M
Detention Basins
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NATS Car Park, Edinburgh
Outlet blocked by a polythene bag
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Outcomes from observation programme

• Guidance on detention basin design detailing
• Sediment
• Mostly from the construction phase
• Detention basins trap much of the sediment
• Need far better construction site management
• Risks posed by sediment in ponds much less than
  feared
• Post development inspections essential prior to
  adoption by Scottish Water
• Whole life costing information (mostly
  confidential)

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Dissemination of performance information

• Engagement with academics at Scottish
  Universities
• SUDSnet developed from this group
• Report published by Sniffer Report SR 02(51)
• SUDS in Scotland The Monitoring Programme of
  the Scottish Universities SUDS Monitoring Group
• Obtained from SUDSnet Website
• Results reported regularly to SUDSWP
• Training
• Scottish Local Authorities
• Online SUDS Course
• Flows and qualities dataset soon available to
  academics

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Thank You Acknowledgements to Taylor Woodrow
Detention Basin B Feb 2004