Wastewater has increasingly become a critical constraint on development.
Although developers benefit from statutory rights to connect and water companies are under a duty to provide adequate sewerage systems, local planning authorities are now frequently delaying or refusing permissions, or imposing conditions preventing occupation, where there is uncertainty as to whether sufficient capacity will be available. These capacity pressures, regulatory scrutiny and infrastructure delivery risk mean that securing a connection is no longer a routine technical step. For many schemes, it is a determinative issue affecting planning, construction program and scheme viability.
It is a constraint that needs developers’ early attention. Developers now need to consider a range of delivery routes, each with different cost, risk and timing implications.
The starting point: can the development connect to the public network?
In most cases, the preferred outcome is a connection to the existing public sewer network, with infrastructure installed by the developer and then adopted by a sewerage undertaker.
Where capacity is available, this is typically the most straightforward and lowest-risk solution. Where it is not, developers need to consider alternative delivery routes at an early stage. It requires the completion of a section 104 agreement (under the Water Industry Act 1991) which remains the primary mechanism for securing adoption of new sewerage infrastructure.
In broad terms, the developer designs and constructs the network and the sewerage undertaker adopts it once it has been completed to the required standard.
Key points in practice:
- Infrastructure must meet approved technical standards to secure the sewerage undertaker’s technical approval
- Adoption follows inspection and a maintenance period
- Agreements are largely in standard form with limited scope for negotiation
Adoption is typically essential to satisfy funders, transfer maintenance responsibility and align with planning.
A delay in the adoption of sewers can impact on plot sales and can cause the adoption of the estate roads to be delayed, which can also impact on plot sales. So avoiding delay is advisable.
Adoption can be derailed if ‘non-developer’ parties need to be party to the section 104 agreement, such as the owners of the new plots or adjacent owners on whose land an easement is required. Good design and timing is essential to avoid these issues.
Once adopted, the sewer and any pumping or balancing infrastructure vests in the sewerage undertaker, so the future upkeep is for them, and they can charge the individual owners and occupiers for the treatment of sewerage.
Requisitions: delivering new infrastructure
Where there is no readily available sewer connection point, developers can rely on the statutory requisition regime to require the undertaker to deliver new infrastructure.
This involves:
- The undertaker designing and delivering the works
- The developer funding the infrastructure
- Formal agreements and security requirements
Requisitions can unlock sites. A sewer requisition effectively removes the need for the developer to assemble third‑party rights upfront, by shifting the burden onto the undertaker’s statutory powers. However, the sewerage undertaker’s costs have to be covered, and the delivery program will be outside the developer’s control.
Appeals and dispute resolution: managing disagreement
The Water Industry Act 1991 provides for disputes with sewerage undertakers—such as the reasonableness of conditions, costs or refusal to connect—to be referred to the regulator (principally Ofwat) for determination.
In practice, while these appeal mechanisms can provide useful leverage in negotiations, they are often time-consuming and are typically used as a last resort where commercial resolution cannot be reached.
Licensed wastewater providers (NAVs): a growing alternative
An increasingly common alternative to dealing with the traditional water companies is for developers to make arrangements with licensed wastewater operators (NAVs), such as ICOSA, IWNL and ESP.
They can offer:
- Greater commercial flexibility
- Potential program advantages
- Alternative security arrangements
However, they often involve bespoke arrangements, including asset transfers and easements, and require careful consideration of long-term operational and funding implications.
On-site solutions: package treatment plants
Where connection is not viable, developers may be able to consider on-site wastewater treatment, such as package treatment plants discharging to a watercourse.
Key considerations include:
- Environmental permitting requirements
- Private ownership and management arrangements
- Planning acceptability and long-term maintenance
These solutions can unlock sites but shift long-term risk away from the statutory regime. Arrangements will be needed to ensure these treatment plants are properly maintained.
Conclusion
Wastewater is now a front-end development issue.
Developers need to identify delivery routes early and integrate them into planning, design and viability.
Handled proactively, wastewater need not delay development. Left too late, it can become a critical barrier to delivery.
