Minster Leas bathing water is on the north coast of the Isle of Sheppey in Kent. The
long sand and shingle beach is gently sloping, flattening to a wide expanse of sand
and mud that is exposed when the tide retreats. The bathing water contains numerous
groynes and is backed by a promenade and a wide, grassy bank, behind which lies the
town of Minster.
There is a storm overflow within the bathing water area, namely Westcliffe Drive.
This overflow operates during heavy rainfall when the sewerage system can become overwhelmed
by the volume of surface water entering the sewer system. The overflow prevent sewage
from backing up pipes and flooding properties. Storm overflow discharges into the
Thames and Medway estuaries are designed to protect bathing water compliance where
necessary.
Grain sewage treatment works, which discharges into the mouth of the Medway 5.8 km
northwest of the bathing water sampling site, was upgraded to further treatment in
2006. Queenborough sewage treatment works, which discharges into the Swale approximately
8.5 km from the bathing water was upgraded to further treatment in 2000 and ultraviolet
disinfection was installed prior to 2005 to improve shellfish water quality. Stoke
sewage treatment works, which discharges into the Medway estuary approximately 10
km from the bathing water, received further treatment prior to 2003.
As part of Southern Water’s Bathing Water Enhancement Programme (from 2016 to 2019),
Southern Water have worked with partners and delivered solutions to improve bathing
water quality.
For the four year (2020-2023) assessment period where data is available, seaweed (macroalgae)
was not assessed as being sufficient to be objectionable, but was observed as being
present on 96% of visits. The bathing water can become covered with seaweed, depending
on tides and the weather. Groynes, rocks and other fixed objects may have a covering
of seaweed which can be slippery.
Modern sewerage systems have two separate systems, one takes foul sewage to sewage
treatment, the other takes rainwater runoff through surface water drains to rivers,
lakes and the sea. Misconnections occur when waste water pipes are plumbed into surface
water drains instead of the foul water sewerage system. This can give rise to pollution
when the waste water is discharged directly to the environment through the surface
water drain. For example, a washing machine or toilet may be incorrectly plumbed so
that it discharges to the surface drain rather than the foul sewage drain.
For the four year (2020-2023) assessment period where data is available, phytoplankton
(microscopic algae) was not assessed as being sufficient to be objectionable, but
was observed as being present on 2% of visits. Phytoplankton (microscopic algae) increase
in number at certain times of the year. This process is known as a phytoplankton bloom.
Blooms of phytoplankton can result in the water appearing discoloured or a foam forming
on the water.
The risks to human health from contact, ingestion or inhalation with marine algae
that currently occur in UK coastal waters are considered to be low. However, some
individuals may be more sensitive and display some reactions.
A common marine algae found in UK coastal waters is Phaeocystis, which is often mistaken
for sewage as it forms foam and a brown scum, but it is non-toxic.
This bathing water is subject to short term pollution procedures. The Environment
Agency makes a daily pollution risk forecast at this site based on the effects of
rain, wind and seasonality on bathing water quality. These factors affect the levels
of bacteria that get washed into the sea from livestock, sewage and urban drainage
via rivers and streams and how they disperse.
When these factors combine to make short term pollution likely we issue a pollution
risk warning on this website and the beach manager will display a sign advising against
bathing at the bathing water. After a short term pollution event, levels of bacteria
typically return to normal after a day or so but it’s possible to have several warning
days in a row. Details of the work to reduce the sources of bacteria at this bathing
water are detailed in this profile.
No warnings were issued last season as this site is new to PRF
All bathing waters have the potential to be affected by a pollution incident and if
this occurs a pollution risk warning will be issued with associated advice against
bathing on this website.
The arterial drainage ditch system inputs via a surface water outfall in the northwest
area of the bathing water and this may receive storm/emergency sewage inputs in wet
weather. There are additional surface water inputs approximately 1 km northwest and
1.8 & 2.5 km southeast of the bathing water sampling site and it is close to the mouths
of both the Thames and Medway estuaries. There is no evidence that these sources affect
bathing water quality at Minster Leas but the bathing water was only designated in
2010 so there is little bathing water compliance data available.
Grain sewage treatment works discharges further treated effluent into the mouth of
the Medway 5.8 km northwest of the bathing water sampling site. Queenborough sewage
treatment works discharges further treated, ultraviolet disinfected effluent into
the Swale approximately 8.5 km from the bathing water sampling site. The Thames and
Medway estuaries both receive treated sewage discharges at various points, resulting
in significant bacteriological loads into these estuaries; however the sewage discharges
are designed to protect bathing water compliance where appropriate.
Environment Agency samplers make observations of litter present on the beach at every
visit, this includes assessments of sewage debris, litter and tar. At Minster Leas
for the four year (2020-2023) assessment period where data is available, sewage debris
was not noted at this site. Litter was assessed as being sufficient to be objectionable
for 2% of visits, with 98% of visits noting the presence of litter. Tarry residue
was not noted at this site.
The natural drainage (hydrological) catchment surrounding the bathing water is approximately
400 hectares. The catchment is mixture of urban and rural land, comprising much of
the town of Minster along with some of the surrounding farmland which is drained by
an arterial drainage/ditch system.
Seaweed (macroalgae) and phytoplankton (microscopic algae) are a natural part of the
marine and freshwater environment. Below we note whether these have been recorded
in quantities sufficient to be a nuisance.
The majority of sewers in England are “combined sewers” and carry both sewage and
surface water from roofs and drains. A storm overflow operates during heavy rainfall
when the sewerage system becomes overwhelmed by the amount of surface water. The overflow
prevents sewage from backing up pipes and flooding properties and gardens. An emergency
overflow will only operate infrequently, for example due to pump failure or blockage
in the sewerage system.
Heavy rain falling on pavements and roads often flows into surface water drains or
highway drains, ending up in local rivers and ultimately the sea. The quality of bathing
water may be adversely affected as a result of such events.
It is the Environment Agency role to drive improvement of water quality at bathing
waters that are at risk of failing higher standards. It is natural for water to run
off the land to the sea. Water quality at a bathing water is dependent upon the type
and area of land (the catchment) draining to the water and the activities undertaken
in that catchment.
