Biodiversity Net Gain Assessment – Somerset

Turning Pasture into Paradise: How SWEL Achieved 122% Biodiversity Net Gain in Somerset

The introduction of mandatory Biodiversity Net Gain (BNG) presents a fantastic opportunity to transform low-value land into thriving ecological hotspots. Our recent project at Wookey, Somerset (BA5 area), demonstrates how strategic, large-scale habitat creation can far exceed the minimum 10% BNG target, turning an agricultural field into a high-quality eco-lodging destination.

From Modified Grassland to 29.3 Habitat Units

SWEL was commissioned in late 2024 to prepare the BNG assessment for the conversion of an existing six-hectare farming field into a sustainable lodging development.

The key ecological challenge was the current habitat: the entire six-hectare site consisted of Modified Grassland, a habitat of low botanical value dominated by common weeds and basic grasses. Although the site’s botanical value was minimal, our plan focused on maximising the ecological uplift through thoughtful habitat creation.

Using the Statutory Biodiversity Metric Tool, the initial habitat value was 24 units. The regulatory minimum for a 10% gain was 26.40 units. Through our planned interventions, we calculated the final outcome would be 29.30 habitat units, delivering an impressive 122% net gain for the site’s biodiversity—a massive positive contribution to the local environment.

A Strategy Built on Habitat Creation

To achieve this substantial gain, the development plan focused entirely on introducing diverse, high-value native habitats:

Pond Creation (1.4 Hectares): The introduction of two new lakes, totalling 1.4 hectares, is a cornerstone of the mitigation. This new aquatic habitat, when planted with carefully screened native pond species, will be a major boost for amphibians, invertebrates, and local flora.

A Relatively “Blank” Canvas

Native Tree and Shrub Planting: We required the planting of 0.5 hectares of native tree cover—including species like Rowan, Silver Birch, and Wild Cherry—to establish new woodland habitat. Additionally, 3.6 hectares of native shrub and wildflower planting is required to enhance the field margins and woodland fringes, providing essential nectar sources and ground cover.

Modified Grassland Enhancement: The remaining grassland, while being developed for four wooden lodges, an orchard, and allotments, will be significantly enhanced to higher-quality native meadow and scrub, replacing the existing low-value species.

Crucially, the development was designed to ensure that no mature trees or hedgerows were felled, protecting the most valuable existing ecological features on the site boundaries.

Beyond BNG: Supporting Local Wildlife

To further cement the development’s commitment to nature, SWEL provided several additional suggestions to benefit specific local species:

Invertebrate Habitats: Promoting the creation and retention of deadwood piles and ‘insect hotels’ to support the declining invertebrate population.

Species-Specific Shelters: We recommended the installation of Bat Boxes and Bird Boxes, strategically positioned away from light spill and facing the correct orientation, alongside the introduction of Hedgehog Houses and habitat connectivity points to support the local hedgehog population.

Sensitive Lighting: Our plan included adherence to strict lighting guidelines to minimise adverse effects on nocturnal wildlife, particularly bats and invertebrates, ensuring the development remains a safe environment for wildlife.

Conclusion: Setting a New Standard for Rural Development

The Wookey project showcases SWEL’s ability to transform a functional rural site into a significant ecological asset. By replacing low-value Modified Grassland with 1.4 hectares of new pond habitat, 0.5 hectares of native woodland, and extensive shrub planting, we not only met the BNG mandate but exceeded it by over 122%. This level of gain ensures the development is ethically responsible, compliant, and contributes profoundly to local biodiversity. Contact SWEL to guide your rural conversion project to a successful, nature-positive outcome.

BNG Assessment SW12

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Building Back Better: How SWEL Delivered Compliant BNG for a Constrained London SW12 Development

Achieving the mandatory 10% Biodiversity Net Gain (BNG) in densely developed areas like London is a significant challenge. Our recent project in the SW12 area of South West London exemplifies how strategic ecological planning and the appropriate use of the BNG metric can successfully unlock planning permission, even on sites with a history of ecological degradation.

We hope you will read about it below, and if you have any questions then please ring us to talk to a human. 🙂

The Site and the BNG Baseline Hurdle

Southwest Environmental (SWEL) was commissioned to prepare a BNG report for a proposed development that will see the construction of four new properties. The site—a rear portion of a residential area—presented a unique constraint: while the site was currently composed primarily of bare ground and hardstanding, retrospective analysis revealed that its ecological value had degraded since the BNG mandatory commencement date (April 2, 2024).

Example Plans Created by SWEL’s Ecologist

Under the BNG rules, if a development is submitted after this date, the baseline must reflect the site’s biodiversity value before any recent degradation occurred (specifically since January 30, 2020). Through analysis of satellite imagery and previous planning documents, our ecologists established the true baseline, which included areas of introduced shrub, vegetated garden, and two previously felled apple trees. This retrospective analysis was crucial, as it set a higher target for the required 10% net gain, demanding a comprehensive mitigation strategy.

Calculating the Gain and Strategising Mitigation

Using the statutory Biodiversity Metric Tool, we calculated the initial baseline habitat score and determined the minimum post-development habitat score required to achieve the necessary 10% net gain.

To meet this goal, our strategy involved a combination of powerful on-site ecological improvements and the strategic use of off-site Biodiversity Credits:

High-Impact Tree Planting: We specified the planting of several 3-meter tall trees, including species like Amelanchier lamarckii, Magnolia denudata, and Prunus avium. This mix was chosen to offer flowers throughout the seasons, significantly boosting potential invertebrate pollination and habitat quality.
Enhanced Shrub and Wildflower Planting: The development will convert large areas of the current bare ground and concrete into soft landscaping. This includes extensive shrub planting and the introduction of diverse native wildflower mixes to further increase biodiversity, particularly supporting pollinator species.
The Role of Biodiversity Credits: Even with ambitious on-site planting, the ecological loss attributed to the historical degradation meant an unavoidable habitat unit shortfall. To bridge this gap and fully satisfy the 10% requirement, the project will purchase the necessary off-site Biodiversity Credits following the strict 2:1 ratio (two statutory credits for every one biodiversity unit offset). This critical step ensures full compliance with the mandatory requirement.

Future-Proofing with Additional Ecological Measures

Beyond the minimum 10% gain, we also provided additional suggestions to future-proof the site and maximise its ecological value:

Invertebrate Habitat: Suggestions included creating log piles and implementing ‘insect hotels’ to promote the growth of the crucial local invertebrate population.

Sensitive Lighting: Recommendations were made to follow specific lighting guidelines to prevent adverse effects on nocturnal species, particularly bats and invertebrates, ensuring the habitat gains are not undermined by light pollution.

By integrating rigorous retrospective analysis with a pragmatic, credit-supported mitigation plan, SWEL successfully developed a pathway for this new residential scheme in London SW12 to achieve the mandatory 10% Biodiversity Net Gain.

Project Success in London SW12

This London SW12 BNG assessment demonstrates SWEL’s expertise in navigating the complex legal requirements of urban development, particularly the mandatory 10% Biodiversity Net Gain. Facing historical site degradation, our ecologists performed a crucial retrospective analysis to establish the correct ecological baseline. The successful strategy combines robust on-site mitigation, featuring diverse tree and shrub planting, with the strategic use of off-site Biodiversity Credits to bridge the remaining habitat deficit. This comprehensive approach, validated in January 2025, ensures full compliance with the statutory metric, securing planning consent while enhancing the local ecological value. Partner with SWEL for rapid, expert BNG solutions in challenging urban environments.

Please contact us if you would like to book a survey.

BNG Assessments London

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London BNG Expertise: Over 20 Assessments in the Last Year

The introduction of mandatory Biodiversity Net Gain (BNG) has created a significant challenge for London developers: how to achieve the required 10% gain within the confines of a highly constrained, urban environment. At SWEL, we have rapidly mobilised our ecological expertise to meet this demand, completing over 20 BNG assessments across various London boroughs in the last year alone.

Top Tip: Please don’t do any site clearance works before you have spoken to our ecologists. It could cost you a great deal of money if chop down a valuable tree (£25,000 per tree).

This hands-on experience has equipped us with the proven strategies needed to navigate the complexities unique to the capital. While many developments have zero or low ecological baselines, the London Plan demands meaningful contributions to green infrastructure. Our track record shows we successfully apply the statutory Defra Metric to urban sites, identifying creative solutions such as:

Urban Greening Factor (UGF) Integration: Ensuring BNG designs complement and achieve the borough’s Urban Greening Factor targets.
Green Roofs and Walls: Maximising ‘high distinctiveness’ habitats in limited space.
Off-site Unit Planning: Securing and allocating registered off-site BNG units where on-site delivery is not physically possible.

Example Plans Created by SWEL’s Ecologist

Rapid Response: Qualified Ecologists Ready for Your Project

We understand that delays in planning can be costly. The challenge faced by many Local Planning Authorities (LPAs)—which often lack the in-house ecological expertise and are reporting staff shortages—can slow down the BNG verification process.

To directly address this speed bottleneck, SWEL has a dedicated team of suitably qualified proactive and personable ecologists standing ready to deliver your assessment on a rapid turnaround. Our experts are proficient in the latest statutory metric and the nuanced requirements of individual London Boroughs. By submitting a robust, accurate BNG Assessment and Habitat Management Plan (HMP) from day one, we help your application move through the system efficiently, avoiding unnecessary requests for further information and reducing your time to consent.

On-Site Mitigation?

Our service goes beyond simply calculating your Biodiversity Net Gain (BNG) deficit; we provide comprehensive strategies for achieving the mandatory 10% net gain, regardless of your site’s complexity. We offer expert advice on both on-site mitigation—designing and integrating ecologically valuable habitats such as green roofs, sustainable drainage features (SuDS), and enhanced landscaping directly into your development plans—and securing off-site BNG credits. Whether your London site is too constrained for on-site delivery, or you need a rapid solution, we guide you through the process of legally purchasing and allocating credits from registered off-site providers, ensuring your project achieves the necessary net gain quickly and compliantly for local authority approval.

Another Example Plan From a BNG Assessment

In conclusion, partnering with Southwest Environmental for your London Biodiversity Net Gain assessment delivers both unrivalled expertise and critical efficiency. Our proven track record of successfully navigating over ten complex BNG assessments in urban settings over the past year, combined with our strategic advice on both on-site design and off-site credits, ensures a compliant and pragmatic path to planning consent. When time is money and regulatory detail is paramount, trust SWEL’s team of qualified ecologists to provide the rapid, robust, and reliable BNG solutions you need to keep your London development on schedule and ethically sound. Contact us today to secure your swift BNG assessment.

A.I. & Environmental Consulting (Snapshot Nov 2025)

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A.I. A Rapidly Developing Productivity Tool For Environmental Consultants

AI is a trans-formative tool. It can check lists of data and help suggest concept in a heartbeat. It is in someways like having the world’s most knowledgeable person sat in the room with you to answer you questions.

So is it a help? Or a hindrance?

Exec Summary

A.I. is an exceptional resource, it can turbo charge daily tasks, and double productivity. But when dealing with images, or matters which require an understanding of context it can trip up.

Whilst the context issue might be improved upon in time, the images may be a tougher nut . . . . . there is a good reason that “captcha” (I am a human) tests use images, machines find them hard to interpret. Its these subtleties that AI still needs to improve on.

Helpful < YES PLEASE

1st Place – Disparate Data Review

Artificial Intelligence (AI), particularly via Large Language Models (LLMs), is a game-changer for environmental scientists tasked with conducting thorough literature reviews and research synthesis. The primary benefit is sheer speed and scale; AI can process hundreds or even thousands of studies—academic articles, technical reports, and raw data—in the time a human would take to read just a handful.

AI employs sophisticated Natural Language Processing (NLP) to quickly identify key themes, methodologies, and findings across this enormous dataset. Advanced methods, such as abstractive summarization, generate entirely new, fluent text that captures the core semantic essence of multiple papers, unlike simple extractive methods that just pull sentences.

This automation allows specialists to pivot from data collection to critical analysis. Instead of spending weeks compiling information, a scientist can instantly receive a structured overview, helping them to quickly identify knowledge gaps and emerging trends, or to compare conflicting conclusions across different studies. While human oversight remains crucial for critical evaluation and ensuring accuracy, AI dramatically enhances the efficiency and comprehensiveness of data synthesis, freeing up expert time for deeper interpretation and application of the findings.

2nd Place – Codes, Standards and Policy

AI is extremely useful for maintaining up-to-date compliance with constantly evolving Codes, Standards, and Policy documents. For environmental and planning specialists, this is critical, where regulatory changes can happen monthly (e.g., changes to BNG metrics, contaminated land guidance, or local planning policy).

AI-powered systems excel at Continuous Monitoring. They can automatically scan legislative databases, government publications, and standard-setting bodies (like BSI or ISO) for new releases, amendments, or errata.

When a change is detected, the AI uses Natural Language Processing (NLP) to automatically compare the new text against existing internal checklists and reports. This pinpoints the exact clauses or policies that have been modified and assesses the impact on ongoing projects. For example, if a local authority updates its protected species policy, the AI instantly flags all relevant project files. This proactive, rapid auditing drastically reduces the risk of non-compliance, saving considerable time and preventing costly project delays due to outdated methodology or incorrect regulatory assumptions.

3rd – Multi-Step Comparisons

A single query delivers an integrated, multi-jurisdictional risk assessment and compliance report, accelerating workflow from hours of searching and cross-referencing to a matter of seconds.

E.g. The scientist has to discard the UK standard and repeat Step 2 with an entirely new jurisdiction, which might use different units, nomenclature, or risk models (e.g., a “Risk Based Screening Level” in the US vs. a “GAC” in the UK):

- The AI retains the original toxic value and automatically queries the required alternate standard—for example, the US EPA Regional Screening Levels (RSLs) for residential exposure.
- It handles the context swap and unit conversion in the background, which is crucial in cross-border environmental work.
- It then provides the comparative outcome: “The US EPA residential RSL for Lead is equivalent to 400 mg/kg. The site value of 500 mg/kg would also be non-compliant in this jurisdiction, exceeding the threshold by 25%.”

This a an amazing tool for insight, rather than having a practical purpose. I would have never considered in the past how a set of results would have been interpreted around the world but now with a few extra quires I can apply my knowledge set in a broad variety of jurisdictions.

4th – Sanity Checking Maths

If you fancy software has just spat out a result say 52kN/m2 then why not have AI sanity check that result for you.

Hindrance < NO THANK YOU

There are still some things that AI cannot do. And don’t get me wrong I thing it is great, but here are a few of the things that I have noticed.

1st – Temporal Context and Urgency

In the conversion of real world data in to facts and then interpretation we often use our eye to look at an object / situation / plant etc and then we use reasoning to determine our onward advice.

AI is excellent at classifying static images, but poor at understanding the timeline or urgency of a visible issue.

Freshness of Damage: AI cannot easily distinguish between an old, established rust stain on concrete (low risk, historical) and a fresh stain from a recent spill (high risk, active contamination event).
Rate of Change: It can struggle to judge the difference between a naturally slow, seasonal browning of a leaf and the rapid, acute chlorosis caused by a sudden, toxic event (e.g., herbicide drift).
Recovery Status: In ecological surveys, AI can map an area that looks disturbed, but a human ecologist can look at the species composition and tell if the ecosystem is actively recovering or if the degradation is ongoing.

2nd – Causality and Mechanism

AI can classify a visible feature but cannot determine what actually caused it without external, non-visual data.

Source of Stain/Damage: It might recognize a “stain on concrete” but cannot tell if it is:

A biotic stain (algae, moss growth).
An abiotic stain (oil/fuel spill from a leaking tank).
A historical artifact (dye from a previous industrial process).

Biotic vs. Abiotic Stress: AI can identify a mark on a leaf (necrosis) but struggles to differentiate if the cause is:

An insect pathogen (e.g., fungal infection).
A nutrient deficiency (abiotic soil problem).
Salt stress (road salt impact near a highway).

Adversarial and Edge Cases: AI is trained on typical examples. It often fails when presented with unusual lighting, partial views, or deliberately obscured evidence, which is common on challenging field sites.

3rd – Context and Regulatory Significance

This is the biggest gap: the ability to link a subtle visual feature to a specific regulatory trigger.

Invasive Species Risk: AI might identify a small patch of Japanese Knotweed shoots. A human ecologist immediately knows that those few shoots represent a legal and financial burden under the Wildlife and Countryside Act, requiring specialist remediation. The AI only sees “plant.”

Protected Species Habitat Potential: When viewing a dilapidated shed or a pile of rubble:

AI sees: “Structure” or “Debris.”

The Scientist sees: “Potential Bat Roost” (cracks, gaps near eaves) or “Reptile Hibernacula” (warm, sheltered rubble pile), triggering the need for a Protected Species Survey before demolition.

Contaminant Plume Indicators: A slight discoloration or “sheen” on water is a subtle visual cue. AI may classify it as a reflection. The human scientist recognizes it instantly as a potential hydrocarbon plume, triggering immediate soil/water sampling and regulatory notification.

In short, AI performs well at classification (e.g., “That is a stain”), t (e.g., “That is a specific type of hydrocarbon stain, likely fresh, requiring immediate notification under planning condition 12”)

4th – Bull$h1t In = Bull$h1t Out

And this third point leads us to the old adage regarding the poop of cows. AI is still very much lead by the questions you ask it. In many ways it seeks to “please” the person asking it questions, and from a scientific perspective this is bad:

Me “Why should we go back to burning coal in the UK?”

AI “Because it is a reliable source of energy”

So this answer is so context blind it is misleading. It answered the question that is true in one very limited sense. And when you point this out to AI then of course it recalculates.

“That’s an excellent observation about the last answer! You are absolutely right; the statement “Because it is a reliable source of energy” is contextually misleading and an oversimplification, especially concerning the UK’s current energy policy and climate commitments.”

A responsible answer to “Why should we go back to burning coal?” needs to address the full picture:

“The only reason to consider ‘going back’ to burning coal is its technical characteristic as a reliable, dispatchable source of energy. However, this reliability is massively outweighed by its environmental, climate, and health costs.”

When asked to analyse the failing we get the following response:

“The bottom line is that the initial error was an algorithmic failure to apply critical, consensus-based context, not a reflection of a political stance. I appreciate you pointing out how easily such an error can be perceived as an endorsement of a non-scientific political view, which is exactly what we strive to prevent.”

https://gemini.google.com/share/b2d642f0f983

If you would like to read the full response then you can on the above link.

Wookey Sewage “Works” – A Disgrace

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Wookey (Somerset) Sewage “Works” – A Disgrace

If something works only half of the time. . . does it work?

If you got in your car, and it only started 60% of the time, its probably due for repairs, and maybe replacement. . . . and if you paid £100 Million for that car, how about that? And then what about if after buying the car the garage had stuffed it full of smelly rubbish. . . are you getting cross yet? Well this is happening to you right now.

“Discovery “

As part of routine investigations for Nutrient Neutrality work we have conducted some research on Wookey Water Recycling Centre.

Wookey Water Recycling Centre (WRC) is only treating 60% of the sewage that is piped to it. It discharges in to the River Axe.

The River Axe – A Beautiful River

Facts and Figures

The Wookey WRC is so neglected, that for 60% of the time over the last 2 years of monitoring, the sewage has been discharged directly in to the river without being treated.

The data sown in the below table is stark. 3,500 approx hours of raw sewage, filled with wet wipes, sanitary towels and condoms etc being but directly in to the River Axe.

While exact spill volumes (in cubic meters) are not readily available in public summaries (water companies typically report duration and frequency), I can provide recent, specific data on the duration and frequency of sewage spills from the Wookey Water Recycling Centre (WRC) near Wells, Somerset, which discharges into the River Axe.¹ This WRC is a key local site operated by Wessex Water.²

The data below represents spills from the Wookey WRC, which is the sewage treatment works (STW) for the area, and associated Combined Sewer Overflows (CSOs) in the River Axe catchment, based on recent Environment Agency and water company data (primarily from 2024 and 2023 reporting periods).

Sewage Spill Data near Wookey, Wells (Wessex Water)

Site Name	Asset Type	Reporting Year (e.g., 2024)	Number of Sewage Dumps	Total Duration (Hours)	Percentage of Total Hours in a Year (%)
Wookey Water Recycling Centre	STW/WRC	2024	197	3,541	40.4%
WOOKEY WATER RECYCLING CENTRE	STW/WRC	2023	148	3,696	42.2%
GLEN COTTAGE CSO	CSO	2024	56	172	2.0%
AXE ROAD COMBINED SEWER OVERFLOW	CSO	2024	11	22	0.25%

Key Takeaways for Wookey WRC (2023/2024 Data)

High Duration: The Wookey Water Recycling Centre (WRC) is a major contributor to pollution in the River Axe.³ For the 2023 reporting period, it had an extremely high total overflow duration of 3,696 hours (equivalent to 154 days of non-stop spilling).
Percentage of Total Hours: For 2023, the Wookey WRC overflowed for 42.2% of the year (3,696 hours / 8,760 total hours in a year). For 2024, the duration was slightly lower at 3,541 hours, or 40.4% of the year. This demonstrates a massive and persistent issue.

Frequency: In 2024, the Wookey WRC spilled 197 times

Who Is To Blame?

Things change. Populations grow. Rain water volumes increase. So yes sewage companies have more work to do. But they aren’t doing what is required. And what’s more they are making huge sums of money whilst permanently ruining our rivers.

Imagine This Was Your Family And The River Was Your Home

Wessex Water’s profits are typically reported for the financial year ending around June 30th. Based on the most recent published financial statements:

Financial Year Ending June 30, 2024 (FY 2023/2024):
- Wessex Water reported a Profit before tax of £17 million
- (This was a significant turnaround from the previous year.)
Financial Year Ending June 30, 2023 (FY 2022/2023):
- The company reported a Loss before tax of £43.2 million.

That’s Bad. . . But

As well as profits from Wessex Water another $65 Million dollars was “shifted” to YTL, Wessex Water’s Owners in Maylaisia. This is problematic.

The profits generated by a UK monopoly (Wessex Water) are being taken out of the country, reducing the potential UK tax base on the subsequent distribution and leading to concerns that a public service is being used to enrich foreign shareholders while the UK faces infrastructure and service issues.

The Mechanism: Debt Loading

Wessex Water is 100% owned by YTL Power International Berhad (a subsidiary of the Malaysian YTL Corporation). The standard practice for UK water companies owned by foreign private equity or conglomerates is to load the UK operating company with large amounts of debt.

Wessex Water takes on debt (either from external markets or, crucially, via intra-group loans from YTL subsidiaries).
The interest payments on this debt are treated as a tax-deductible expense in the UK, which significantly reduces the UK company’s taxable profit.
This interest income then flows to the foreign parent (YTL) or its offshore affiliates, where it may be taxed at a lower rate or potentially zero, depending on the routing mechanism (such as using “quoted Eurobonds”).

This transfer of wealth in the form of tax-deductible interest is the core volume of the potential profit shifting.

Financial Estimation

Publicly available accounts for Wessex Water Services Finance Plc (which holds much of the group debt) provide the clearest indication of the scale:

Total Interest Expense: For the financial year ending June 30, 2021, Wessex Water reported Financial Expenses (primarily interest payments) of approximately £78.7 million.
Cash Flow Interest Paid: The actual cash flow for “Interest Paid” in the same period was £62.1 million.

This range of £62 million to £78 million represents the annual interest payment burden that reduces the company’s UK taxable profit and transfers value to its owners/affiliates.

Is The Axe Your Local River?

Lots of people are making money whilst dumping plastics, and other damaging materials in your local river. Not to mention all of the $h1t.

Do I Need To Do A Percolation Test?

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Do I Need To Do A Percolation Test?

Who Is Asking For The Percolation Test Results

If you are reading this mt guess is that you have been asked to carry out a percolation test either by:

You Building Inspector
You Planning Officer

Up until about 5 years ago percolation tests were strictly the domain of building control, if they weren’t building control then they would have been carried out by a drainage engineer or a septic tank installer prior to installing a drainage field.

Percolation Testing 30cm x 30cm Hole

A building inspector might ask to see the results of your percolation testing so as to check the design of your drainage field., as might a drainage engineer if their scope does not include for obtaining the results.

What is recently new is that a planning officer may also ask for results of percolation testing. This can seam quite annoying given that it contrasts with historical requirements. However, in some cases there is a justification for doing so.

Soak-Away Testing . . . Big Hole

Why Am I Being Asked For Percolation Testing?

If you are being asked by building regs or a drainage engineer then the answer is reasonably obvious. It is to provide data (VP Rate) so you can design the drainage field at the correct size.

But why i your planning officer (or consultee) asking for percolation testing? We would suggest there are two reasons:

Less likely – The planning officer is overstretched and doesn’t have time to determine your application, and as such they will ask for this extra detail (with no real justification for doing so ) in order to buy themselves more time.
More likely – The planning officer is worried that after planning is granted it may become apparent that infiltration drainage is not viable on site. Lets have look as to why this might be the case:

Why Is A Drainage Field Not Viable On My Site?

Reason 1 – Lack of Space

Is there enough room on site for a drainage field? In soils were water logging is sometimes a problem like clays. The drainage field required might be very large, you don’t know how large until you have carried out the percolation tests.

Reason 2 – Clay Soils

If the VP rate is too low. Then a drainage field may not work. If you then intend to use a drainage mound, what size will it be and will this affect the layout or the appearance of the planning proposal.

Reason 3 – Very Permeable / Pervious Ground

Just as a VP rate can be too low. It can also be too high. So f you are o a site with clean sandy soils, or gravels then the permeability might be too high. This can also be a problem on ground where the has cracks in it like limestone, you might hit a fissure and all of the water drains away very quickly. Luckily this maximum rate only applies to old fashioned septic tanks, and you can get around it by using a treatment plant.

What Can Do If I Am Asked For Percolation Tests By Planning Officer?

Follow the below handy list:

Is the request justified? If you live in the middle o nowhere with huge areas for the drainage field , and geological maps show that that you will get good drainage. . . why are you being asked.
In all other instances just do the tests. We can do them or you, or you can find instruction on how to do them in the building regulations.
Is the VP rate too low? Investigate a drainage mound, or perhaps investigate using a treatment plant and discharging to a river. Another option might be to run a pipe (perhaps or a long way) and connect to mains sewer.
Is the VP Rate Too High? Swap you septic tank to a treat plant.

A very complicated solution is a borehole soak-away. his costs a lot o money and you will need to get a licence from the Environment Agency. If you thing drilling a 30m deep hole sounds difficult . . . try getting a license from the Environment Agency.

Bored Already?

Just get us to do it for you. Please contact us for a quotation.

Do we have any better alternatives for paper cups that are biodegradable?

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Do we have any better alternatives for paper cups that are biodegradable?

There are several promising alternatives to traditional paper cups that are more environmentally friendly and truly biodegradable or compostable. The key issue with standard paper cups is that they are lined with a thin layer of polyethylene (PE) plastic to make them waterproof, which makes them very difficult to recycle or compost.

Here are some of the most prominent and better alternatives:

1. Paper Cups with Bio-based Linings (PLA and Aqueous Coatings)

Many of the “eco-friendly” paper cups on the market today are still made of paper, but they replace the traditional plastic lining with a plant-based alternative.

PLA (Polylactic Acid) Lining: This is a bioplastic made from renewable resources like corn starch or sugarcane. It provides the necessary waterproof and heat-resistant barrier. While these cups are considered compostable, they typically require an industrial composting facility to break down effectively due to the high temperatures needed.
Aqueous Coating: This is a newer, water-based dispersion coating that is applied like paint and absorbed into the paper fibers. It uses less material than other coatings and is designed to be home compostable and recyclable. Some companies are now offering cups with this technology.

2. Cups Made from Other Plant-based Materials

Beyond paper, there are alternatives made entirely from different plant fibers, which can be highly effective.

Bagasse Cups: Bagasse is the fibrous residue left over after sugarcane is crushed to extract its juice. These cups are strong, biodegradable, and can handle both hot and cold liquids. They are often noted for their ability to decompose relatively quickly, even in home composting.

Bamboo Fiber Cups: Bamboo is a rapidly renewable resource that requires minimal water and resources to grow. Cups made from bamboo fiber are strong, biodegradable, and a good alternative to both plastic and traditional paper cups

3. Truly Biodegradable Plastic Cups (PLA)

While paper cups are a primary concern, single-use clear plastic cups also have a large environmental footprint. The alternative for these is also often made from PLA.

PLA Plastic Cups: Clear cups for cold drinks, like smoothies and iced coffees, are now commonly made from PLA. They have the look and feel of conventional plastic but are compostable in industrial facilities. They are not suitable for hot liquids.

4. The Best Alternative: Reusable

It’s important to remember that even the most “biodegradable” or “compostable” single-use cups still require resources to produce and a proper waste management system to break down. The most sustainable and effective alternative is always a reusable cup. Many coffee shops and businesses now encourage or even incentivize customers to bring their own reusable cups, often offering a discount.

Above example from the world’s best music festival.

You would need to use the above cup quite a few times in order to balance out the carbon footprint. . . . but not hard as would last a life time, even if you loose it, someone else will make use of it.

Do I Really Need An NNMAS?

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Do I Really Need An NNMAS?

If you have a planning application on the go in Somerset (good luck) or Dorset. Then you may have been asked for an NNAMS (Somerset) or NNMAS (Dorset).

But if you are on an urban site (in a town or city) then the chances are you don’t need an NNMAS or NNAMS. . . you would be better of with a SHRA (Shadow Habitats Regulation Assessment)

image that shows "NNAMS" and "NNMAS" in separate bubble floating around with someone trying to shoot them down with a laser gun dinosaur wearing sunglasses labelled SHRA behind the stick figure creeping up on him, please keep rest of image the same

NNMAS or NNAMS – – -snap: SHRA

NNAMS or NNMAS. . . . It’s just a name.

First off lets just clear up a slight difference in names, and it is just that the two reports are very similar and despite local differences contain mostly the same information.

This abbreviation has slightly different meanings depending whether you are in Somerset or Dorset:

NNAMS: This stands for Nutrient Neutrality Assessment and Mitigation Strategy. This is the specific term used in a key search result from Somerset Council, which is the authority most strongly associated with the origin of this type of document. The council’s guidance refers to this exact phrase and abbreviation.
NNMAS: This stands for Nutrient Neutrality and Mitigation Statement. While this is a plausible and frequently used term, the official document from Somerset Council uses “Assessment and Mitigation Strategy,” making “NNAMS” the more likely correct abbreviation for that specific council’s document.

Why You Might Not Need The NNAMS or NNMAS

There are certain situations where you might not need an NNAMS or NNMAS.

You Don’t need a NNAMS or NNMAS

If you site is in a town such as Taunton or Yeovil, then in reality you will very likely be on mains drainage, and your will probably not have a spare hectare for planting trees on (on site mitigation), you will need to buy nutrient credits.

It is far better in this case to get a Shadow Habitats Regulation Assessment (SHRA) this costs the same as an NNMAS perhaps a little less, and has the major advantage that is saves you time in planning process. Explanation:

When you submit an NNMAS to the council they use this to inform their own “appropriate assessment” being councils all over the UK are so overwhelmed (primarily due to underfunding) you will have to wait weeks, if not months for them to undertake their own SHRA. So why not do it for them. They would need the NNMAS anyway. . .

You Do need a NNAMS or NNMAS

On rural site with private drainage, and some form of on site mitigation you will need an NNMAS. This is because the the structure of the Shadow Habitats Regulation Assessment (SHRA) does not allow for all of the extra detail such as drainage plans and tree planting schedules etc.

In these cases you can have you NNMAS prepared and wait for council to undertake their own SHRA, or you can have us to it for you. If its is commissioned alongside NNAMS or NNMAS then we can do a reduced rate as a lot of duplicate work.

If you need NNAMS or NNMAS then please check with us (wt@southwest-environmental.co.uk), as you may not need it, and there may be a better option for you.

How Does Light Pollution Affect Moths?

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How Does Light Pollution Affect Moths?

Moths are often overlooked in favor of their more famous cousins, butterflies. However, these amazing and diverse insects are vital to our ecosystems. They are essential pollinators for many plants, including food crops, and serve as a crucial food source for a variety of wildlife, such as bats and birds. Sadly, moth populations in the UK have declined significantly, with numbers falling by an average of 33% since the 1960s. While habitat loss and climate change are major factors, a growing threat is “Artificial Light at Night” (ALAN), more commonly known as light pollution.

In the last 5 years we have seen lighting assessment and lux contour plans being required on more and more planning applications.

In their recent publication Butterfly Conservation have revealed some interesting facts:

How Light Pollution Harms Moths

The report highlights several ways in which artificial light disrupts the natural behavior of moths:

Disorientation and Exhaustion: Moths are naturally drawn to light, but this instinct can lead them astray. Artificial lights disorient them, causing them to expend valuable energy circling around a light source instead of finding food or a mate. This can leave them exhausted and vulnerable.
Increased Predation: Moths that congregate around artificial lights become easy targets for nocturnal predators like bats. The lights make them more visible, disoriented, and susceptible to being eaten.
Disrupted Life Cycles: The impact of light pollution extends beyond adult moths. Studies have shown that moth caterpillar numbers are significantly lower in areas with LED streetlights compared to unlit areas. This suggests that artificial light disrupts the entire life cycle, potentially by affecting a moth’s ability to lay eggs or by changing the nutritional quality of their host plants.

Insects are Attracted to Light, Modifying Behaviour of Predators

What Can We Do?

The good news is that by making some simple changes, we can help protect moths and other nocturnal insects. These are some of the measures that we define in our lighting assessments

Reduce Lighting: Use timers or motion sensors for outdoor lights so they are only on when needed.
Replace Bulbs: When lighting is necessary, choose bulbs that emit less blue and UV light, as these are most disruptive to insects.
Minimize Spillage: Close curtains and blinds at night to reduce light spilling from your home into the surrounding environment.

By being more mindful of our use of artificial light, we can play a significant role in helping to reverse the decline of these important and fascinating creatures.

If you would like a quotation for a lighting assessment or lux contour plan please contact us. Direct email: wt@southwest-environmental.co.uk

How many BNG Credits per Acre?

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How many BNG Credits per Acre?

If you are considering giving up some of you farm land for BNG credits, then of course you will need to know how many BNG credits you will get per acre. The land you are giving up for BNG will be out of use for many years and as such it is only right to investigate the returns you might expect.

BNG Credits are created by changing land from one use to another. For example a field to woodland, or some low lying meadows in to wetlands.

Not Just “How Many”

The first thing to realize is that it is not just a case of “how many”. As with wine or stamps the price of credits varies based on “distinctiveness“. Grassland may have quite low “distinctiveness”, whilst a lake would have very high distinctiveness. This can affect the price of each credit by 400%. (£40,000 to £200,000 or more).

Wetlands are a Very Good Option for BNG

But. How Many BNG Credits per Acre?

The short answer might be about 1 BNG Credit per Acre. Or 2 BNG Credits per Hectare.

This is based a few real world examples we have worked on where say 4 hectares of marginal land yielded around 7 BNG Credits.

But of course it is not that simple. The credits come from improvements in biodiversity. So if you start with good bio diversity (say scrub) then you will gain less when you “upgrade” to woodland.

Your best possible “yield” would be to upgrade mono-cultural farmland to something like a swamp or lake. But in terms of profit (especially in the long term) perhaps it is better to use scruffy marginal land and make fewer credits.

A last word. If you are think perhaps you could “tidy up” an area and then re-wild it in a year of two remember that what you do is all being recorded by satellites (google earth), and part of the process if proving that the land has not recently been changed.

Prices Can Vary Per Unit

Want to Know More

If you would like to know how much money you could make from BNG credits, then please do contact us (wt@southwest-environmental.co.uk) and we can arrange for our ecologist to advise you on the best way forward.