Waste water drainage
Where there is a public sewerage system, foul drainage from
development within and close to the settlement envelope should be
directed to that system. If the system has insufficient capacity,
then early dialogue with
Scottish Water 
will be
required to determine if works are planned to overcome this
problem, or what developer pro-rata contributions will be necessary
to remove the constraint.
Where there is no or limited public sewerage infrastructure, we
would still expect the development of strategic infrastructure to
adoptable standards. Contact should be made with Scottish
Water to determine the standards required to ensure adoption of new
infrastructure.
Please note that we are not likely to support proposals for
private foul drainage systems for significant development (eg more
than 25 houses) where development of public infrastructure is the
sustainable long-term solution. An interim solution may be
acceptable provided an appropriate upgrade has been agreed and
there will be no unacceptable impact on the water environment.
Scottish Planning Policy
Scottish
Planning Policy (SPP) sets
out the Scottish Government’s policy on nationally important land
use planning matters. The SPP states that, “For large scale
development proposals in areas where drainage is already
constrained or otherwise problematic or if there would be off-site
effects, a comprehensive drainage assessment will be required”
(paragraph 210).
Planning Advice Notes
Planning Advice Notes (PANS) provide advice on good practice and information including
PAN 79
Water and Drainage .
SEPA policy and guidance
Areas of Cumulative Drainage Impact GIS
Layer
The Waste water
drainage consultation area GIS layer 
(30k) show areas
where a proliferation of private waste water arrangements is
currently causing environmental problems. We should be consulted on
all developments proposing private waste water arrangements in
these areas to enable us to assess any significant potential
environmental and health impacts. The layer can also be used in
development planning to identify sensitive areas where first time
public sewerage may be a requirement for allocations. The Waste water
drainage consultaion area GIS layer (30k) is an ESRI
shapefile developed in ArcGIS for use by planning authorities (it
may need to be installed by technical staff for use within your
existing GIS system). Waste Water
Drainage Consultation area GIS layer metadata 
(19k) provides further on the
use of tis layer within GIS. For convenience we have also provided
a spreadsheet
listing these by local authority areas 
(30k).
Regulatory and best practice advice