Bathing and shellfish waters as a planning constraint

Designated bathing waters and shellfish water protected areas rarely appear on a constraints plan, and they catch developers out for that reason. Neither designation stops development. Both work through what your drainage is allowed to discharge, which means the constraint lands on the foul drainage strategy, the surface water treatment train and the sewerage undertaker's capacity position rather than on the land use.

If a site drains, directly or through a sewer, to a catchment serving a designated bathing water or shellfish water, expect the Environment Agency and the water undertaker to take a position on your drainage before anyone looks at the layout.

What designation means

Bathing waters in England are designated under the Bathing Water Regulations 2013 and monitored by the Environment Agency through a sampling season that runs from 15 May to 30 September. Each water is classified on the results of that monitoring, and the classification is published. The pollutants that drive it are bacterial: E. coli and intestinal enterococci.

Shellfish water protected areas are designated under the water framework directive regulations, which carry over the protection formerly provided by the shellfish waters directive. The standards there concern microbiological quality in shellfish flesh and the substances that affect it, and the practical consequence is the same: the receiving water has a quality objective that a new discharge must not compromise.

Both sit inside the wider duty not to cause deterioration in the status of a water body. That duty is what gives the Environment Agency its grip on an application, and it applies whether or not the site is near the coast, because a river catchment can deliver a discharge to a bathing water many kilometres downstream.

Finding designated waters near a site

Three checks, none of which takes long.

1. Look up the site's surface water catchment and its receiving water body, then check whether that water body is listed as a protected area for bathing or shellfish purposes.
2. Check the designation layers on the national mapping service alongside your other constraint layers, so the result sits in the same place as your flood and ecology checks.
3. Ask the sewerage undertaker, at pre-application stage, whether the receiving works discharges to a designated water and whether it has a bathing water or shellfish water consent condition.

The third is the one that changes designs. A treatment works with a bacterial consent has different headroom from one without, and the undertaker knows which of its works are constrained.

A site several kilometres inland can still be in a bathing water catchment. Do not treat this as a coastal issue only.

Discharge standards and their effect on drainage

For foul drainage, the question is where the flow ends up. A connection to a public sewer transfers the problem to the undertaker, whose works may need to treat to a tighter bacterial standard, often involving ultraviolet disinfection. Where capacity or consent headroom is short, the undertaker's response is a phasing position rather than a refusal, and the planning outcome is a condition preventing occupation until an upgrade is complete.

For a site on private drainage, the Environment Agency's position hardens. A new package treatment plant discharging to a watercourse in a bathing water catchment will attract scrutiny on bacterial removal that a standard secondary treatment plant does not deliver, and tertiary treatment may be required. Infiltration to ground, where the geology allows it, is often the easier answer for exactly that reason. The groundwater route brings its own constraints, and the position is similar to development over a source protection zone where the pathway rather than the land use governs.

Surface water matters more than people expect. Bacterial loading in urban runoff is real, and a new outfall close to a designated bathing water will be assessed on water quality as well as on flow. Design the treatment train with the water quality objective in mind, record the treatment stages against the pollution indices in the recognised drainage guidance, and show the result in the Drainage Strategy.

Foul drainage capacity in a designated catchment

The capacity conversation in these catchments has a particular shape. The undertaker will usually confirm that it has a duty to accept foul flows, then explain that the receiving works is at or near its consented limit, then describe an investment timetable.

That leaves three realistic planning outcomes. A Grampian condition preventing occupation until identified off-site works are delivered. A phasing plan that releases units in line with headroom. Or an on-site solution, which for anything above a handful of dwellings is rarely acceptable where a sewer exists.

Put the correspondence in the application. A Foul Sewage Assessment that sets out the connection point, the receiving works, the consent position as advised by the undertaker, the flows generated and the proposed phasing answers the consultee's questions before they are asked. Leaving it to the consultation response adds weeks.

One distinction worth drawing in the document. Nutrient neutrality, which affects catchments draining to protected habitats sites, operates through the habitats regulations and an entirely separate assessment. Bathing and shellfish water constraints are not nutrient neutrality, and conflating the two in a planning statement makes the rest of the document look less reliable.

Construction phase controls

Silt is the construction risk in these catchments, and it is the one that produces an objection from the Environment Agency on an otherwise straightforward scheme. Earthworks on a sloping coastal site, a dewatering discharge from a foundation excavation, and wheel washing water all carry sediment and whatever the sediment carries.

A Construction Management Plan for a site in a designated catchment should name the receiving water, set out silt management with specific measures rather than a statement of intent, identify any dewatering and the permit position for it, and state the pollution incident response arrangements. Where works extend below the mean high water springs line, a marine licence under the Marine and Coastal Access Act 2009 is a separate consent with its own timetable.

Timing helps. Scheduling the largest earthworks outside the bathing season reduces the consequence of an incident and is a straightforward offer to make.

Consultee positions and typical conditions

The Environment Agency comments on the foul and surface water strategy and on any direct discharge. The sewerage undertaker comments on capacity and the connection point. The local authority's environmental protection team takes an interest where private drainage is proposed. Where the designated water overlaps a special area of conservation or a site of special scientific interest, Natural England's position runs alongside on habitats grounds.

Conditions that recur in these catchments include a foul drainage scheme to be approved before development above slab level, a Grampian condition tied to off-site reinforcement, a surface water scheme with specified treatment stages and a maintenance regime, a construction environmental management plan secured before works start, and a restriction on discharge during the bathing season for any temporary works.

Evidence to submit

Keep the package proportionate to the scale of the proposal, but include all of the following where a designated water is in the catchment.

1. A statement identifying the receiving water body, its designation and its published classification, with the source of each.
2. The foul drainage strategy with the connection point, the receiving treatment works and the undertaker's written capacity position.
3. The surface water strategy with the discharge point, the rate, the treatment stages and the water quality assessment behind them.
4. Percolation or infiltration test results where a ground discharge is proposed, with groundwater levels.
5. A construction environmental management plan dealing with silt, dewatering and incident response.
6. Where relevant, a water framework directive compliance assessment for the proposed discharge.

The honest uncertainty here is timing rather than principle. Investment programmes for treatment works move, and a capacity position obtained a year before submission may have changed by determination. Date the undertaker's advice in the document and ask for it again if the application stalls.

This is general guidance, not legal advice. Discharge standards and capacity positions are site specific, so check the position with the Environment Agency, your sewerage undertaker and your local planning authority before relying on anything described here.

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