Privacy Policy — TrenchCalc by EngSiteTools

Effective Date: January 29, 2026

TrenchCalc ("the app") is a utility tool designed for engineering professionals to calculate trench volumes and backfill estimates. We value your privacy and only collect the minimum data necessary to deliver core functionality.

TL;DR: We collect your Apple or Google account info for login and purchase management. We store your company/business profile information (name, job title, company name, address, phone, etc.) to display in the app and manage your account. We use location services for weather information, which is provided by Open-Meteo. Project calculations are stored locally on your device. Web seat payments run through Stripe (we only keep Stripe customer/subscription IDs; card data stays with Stripe). We don't show ads or sell your data.

Version History

v1.1 — 12 February 2026: Added SCC/DPA links, consolidated processor/transfer table, clarified Stripe handling, and published lawful-basis mapping.
v1.0 — 29 January 2026: Initial publication.

Information We Collect

Authentication: When you sign in, we use Firebase Authentication (provided by Google) to securely manage your login. You can sign in using Apple Sign In or Google Sign In. We collect your account identifier and email address (or Apple's private relay email if you choose to hide your email) to authenticate your account. We configure our primary authentication project in Australia (Sydney region), but Firebase Authentication and identity providers operate on global infrastructure and may process data outside Australia.
Company/Business Profile: When you create an account or use the Company Profile in the app, we collect and store: first name, last name, job title, company name, company size, industry type, business address, and business phone. This data is stored in our secure database (Firebase/Firestore) and is used to display your profile in the app and to manage your account.
Location Information: If you enable location services, we use your device's GPS coordinates for the following purposes (each is reasonably necessary for the stated feature):
- Weather: Device location (or your last cached location) is used to request weather from Open-Meteo for: (a) cement placement advisory and app bar weather in the main calculator. See Open-Meteo Terms & Privacy. The app calls Open-Meteo directly; coordinates are not sent to our servers for weather.
- Calculator and Soil Testing: If you use "Get GPS" in the main calculator, coordinates are converted to easting/northing and displayed in the Soil Testing tab; they are also used for the weather features above. Last coordinates are cached on your device for weather when GPS is unavailable. Not sent to our servers.
- Photos: When you capture or import photos, we attach GPS coordinates (and optionally altitude and accuracy) to the photo for geotagging. These are stored only on your device and used to show capture location on the photo and on the minimap (photo pins). We do not upload photo location to our servers.
- LiDAR / Site Survey: If a survey has a reference location, we may use live GPS to show your position on the 3D point cloud view ("you are here"). This is used only on your device and is not sent to our servers.
You can manually enter coordinates in the calculator instead of using GPS, or disable location services in your device settings.
Project Information: Project details, calculations, and site data are stored locally on your device. This data is not uploaded to our servers.
Purchases: For app subscriptions, we use RevenueCat to manage your subscription status. RevenueCat receives your email address to link your subscription across devices, along with purchase and renewal events from the app stores (Apple App Store and Google Play). RevenueCat is a US-based service. We do not receive your payment card details directly—these are handled by Apple or Google. See RevenueCat's Privacy Policy. For business seat subscriptions purchased on our website, payment is processed by Stripe. We store Stripe customer and subscription IDs to manage your seat subscription; we do not receive or store your payment card details—Stripe handles those. See Stripe's Privacy Policy.
Anonymous Feedback: If you delete your account, you may optionally leave feedback. This is stored anonymously and cannot be linked back to your identity.

How We Collect Information

We collect personal information in the following ways:

Directly from you: When you create an account (using Apple Sign In or Google Sign In), sign in, use app features (including when you provide or edit your Company Profile), or contact us for support
Through app usage: When you use TrenchCalc features, such as weather lookup, or subscription management
From third-party services: We receive subscription status information from RevenueCat, payment and subscription data from Stripe when you purchase seats on the website, authentication data from Firebase Authentication (Google), account information from Apple or Google when you use social login, weather data from Open-Meteo

Where reasonable and practicable, we collect personal information directly from you. We will notify you if we collect information from third parties not disclosed in this privacy policy.

Purpose for Collection, Use, and Disclosure

We collect, hold, and use your personal information for the following purposes:

To provide services: To deliver TrenchCalc functionality, including authentication, subscription management, weather information, and other app features
To display and manage your company profile: To show your profile within the app and to manage your account
To process transactions: To manage your subscription status and payment processing through third-party services
To improve our services: To respond to support requests, fix bugs, and plan enhancements based on aggregated feedback. We do not run in-app analytics or behavioural tracking.
To communicate with you: To respond to your inquiries, provide customer support, and send important service-related notifications
To comply with legal obligations: To meet our legal and regulatory requirements, including data protection laws
To protect our services: To detect and prevent fraud, abuse, and security threats

We disclose your information to the third-party service providers listed in the "Third-Party Services" section solely for the purposes stated above and under appropriate data processing agreements.

If the app crashes, Apple (App Store Connect) or Google (Google Play Console) may generate crash reports. We review those platform-provided reports to diagnose issues. We do not integrate third-party crash-reporting SDKs such as Firebase Crashlytics.

Third-Party Services

TrenchCalc uses the following third-party services:

Authentication

Firebase Authentication (Google): Secure user authentication. Primary project configured in Australia (Sydney region); Authentication infrastructure and CDN operate globally (including the United States). Cross-border transfers rely on Google’s EU Standard Contractual Clauses and Google Cloud Data Processing Addendum. See Firebase Privacy Policy.

Payments

RevenueCat: Subscription and purchase management. US-based service. We rely on RevenueCat’s EU Standard Contractual Clauses for international transfers. See RevenueCat Privacy Policy.
Stripe: Payment processing for seat subscriptions purchased on our website. US-based service. We rely on Stripe’s EU Standard Contractual Clauses (with UK Addendum where applicable) for transfers. See Stripe Privacy Policy.

Weather Data

Open-Meteo: Provides weather forecasts based on your GPS coordinates. Open-Meteo is based in the EU (Germany) and processes requests in accordance with EU privacy laws. See Open-Meteo Terms & Privacy.

These services have their own privacy policies and handle your data according to their respective terms and applicable data protection laws.

What We Do Not Collect

We do not store trench calculation or project data in the cloud—calculations remain on your device. We do store your company profile information as described above.
We do not access your device contacts, photos, or files (except photos you explicitly add to site diaries)
We do not show ads or track you across other apps
We do not sell your personal information to third parties
We do not use Firebase Analytics, Crashlytics, or other in-app analytics SDKs; crash diagnostics rely on Apple and Google platform crash reports.
We do not adopt or use government-related identifiers (such as Australian Tax File Numbers or Medicare numbers) as account identifiers.

We share data with third-party service providers only as described in this policy and solely to provide our services.

No Marketing Communications

TrenchCalc does not send marketing emails, promotional messages, newsletters, or any other marketing communications. We only send essential service-related notifications (such as account verification or important policy updates) when necessary.

No Advertising

TrenchCalc does not display advertisements, use targeted advertising, or sell your personal information to advertisers. We do not use your data for advertising purposes, and we do not share your information with advertising networks or marketing companies.

Do Not Track

Your browser settings may allow you to transmit a "Do Not Track" signal when you visit various websites. Like many websites, our website is not designed to respond to "Do Not Track" signals received from browsers. To learn more about "Do Not Track" signals, you can visit www.allaboutdnt.com.

The TrenchCalc mobile apps themselves do not set cookies or similar tracking technologies beyond device-level preferences. Our public website uses only the cookies and scripts disclosed in the EngSiteTools privacy policy (e.g., reCAPTCHA, analytics if enabled, cookie-preference storage). You can manage those preferences through the cookie banner on the website.

Consequences of Not Providing Information

Providing personal information is generally optional, but certain features require specific data to function:

Account creation: An Apple or Google account is required to create an account and access premium features
Subscription management: Subscription status information is required to provide access to premium features
Weather features: Location information is required to provide weather data (you can enter coordinates manually)

If you choose not to provide requested information, we may not be able to provide you with certain features or services. You can use the free tier of TrenchCalc without creating an account, but account creation is required for premium features.

Unsolicited Personal Information

Sometimes we receive personal information we did not ask for (for example, extra details in support emails, feedback sent by email, or misdirected correspondence). Under Australian Privacy Principle 4 (APP 4), when that happens we assess whether we could have collected that information under APP 3 (i.e. whether it is reasonably necessary for our functions or activities). If we could have collected it, we treat it in accordance with this privacy policy. If not, we destroy or de-identify the information as soon as practicable, unless we are required or authorised by law to retain it.

Data Retention

You may delete your account at any time from the profile screen (for individual accounts) or from the dashboard (for business accounts). This removes your login data from our authentication system and your company profile data from our systems.

Business Account Deletion: If you have a business account with provisioned seat users, deleting your account will also permanently delete all users you have provisioned. Additionally, any active seat subscription will be automatically canceled and you will not be charged for future billing periods.

Account Data: Retained until account deletion
Company profile data: Removed when you delete your account
Provisioned seat users (business accounts): All users you have provisioned are permanently deleted when you delete your business account
Stripe subscriptions: Active seat subscriptions are automatically canceled when you delete your business account
Anonymous Feedback: If submitted during account deletion, this is not linked to your user ID and cannot be deleted
Third-Party Data: Data held by our third-party service providers (RevenueCat, Stripe, Open-Meteo) is subject to their respective retention policies

Destruction when no longer needed: Under APP 11, we destroy or de-identify personal information that is no longer needed. When you delete your account, we remove your authentication record, Firestore data (company profile, quotas), and cancel associated subscriptions. Backup copies held by our providers are subject to their retention periods. We do not retain your personal information after account deletion except where required by law (e.g. tax records) or where data has been anonymised (e.g. anonymous feedback).

Your Rights

Under GDPR, Australian Privacy Act, and other privacy laws, you may have the right to:

Access: Request a copy of your personal information
Rectification: Request correction of any inaccurate data
Erasure: Delete your account and associated data at any time (right to be forgotten)
Portability: Export your data in a machine-readable format
Object: Object to processing of your personal information
Opt Out: Opt out of optional data collection

How to Exercise Your Access and Correction Rights

To request access to or correction of your personal information:

Business account holders can update their company profile details at any time in the TrenchCalc web dashboard (Company page). For any other updates or formal access/correction requests, follow the steps below.

Contact us: Send an email to support@engsitetools.com with your request
Proof of identity: We may require proof of identity to ensure personal information is provided only to the correct person and to protect the privacy of others
Fees: No fees are charged for access or correction requests
Timeframe: We acknowledge requests promptly and aim to provide a full response within 30 days
Response: We will respond to your request in accordance with applicable privacy laws
If we refuse a correction: We will provide written reasons, outline complaint avenues, and, if you ask us to, attach a statement of your disagreement to the relevant record.
Appeals: You may lodge a complaint about any decision (see "Privacy Complaints" section below)

Australian Privacy Rights

TrenchCalc is an Australian application and we comply with the Australian Privacy Act 1988 (Cth) and the Australian Privacy Principles (APPs). If you are located in Australia, you have the following rights:

Access: You have the right to request access to the personal information we hold about you
Correction: You have the right to request correction of any inaccurate, incomplete, or out-of-date personal information
Complaints: You have the right to make a complaint about how we handle your personal information. If you are not satisfied with our response, you can contact the Office of the Australian Information Commissioner (OAIC) at www.oaic.gov.au
Anonymity: Where lawful and practicable, you have the right to interact with us anonymously or using a pseudonym
Cross-border disclosure: We disclose personal information to overseas recipients (United States and European Union) as described in this policy. We take reasonable steps to ensure overseas recipients handle your information in accordance with Australian privacy law.

To exercise your Australian privacy rights, contact us at: support@engsitetools.com

Residents of Certain U.S. States

If you are a U.S. resident, depending on the state you live in, you may have some or all of the rights listed below in relation to information that we have collected about you. However, these rights are not absolute, and in certain cases, we may decline your request as permitted by law, including in the event you reside in a state that does not currently grant you these rights.

Right to Access: You may have a right to request that we confirm whether we process information about you and give you access to that information in a portable and, to the extent technically feasible, readily usable format that allows you to transmit the information to another business without impediment.
Right to Delete: You may have a right to request that we delete information we maintain about you.
Right to Correct: You may have a right to request that we correct inaccurate information we maintain about you.
Right to Opt-out of Targeted Advertising, Profiling, or Selling: You may have a right to opt-out of the processing of your information for the purposes of targeted advertising, the profiling of your information in furtherance of decisions that produce legal or similarly significant effects, and/or the sale of your information (as all such terms and concepts are defined under applicable law). We do not engage in targeted advertising, profiling, or selling of personal information.

You may exercise any of these rights by contacting us using the information provided in the "Contact Us" section below. We will not discriminate against you for exercising any of these rights. We may need to collect information from you to verify your identity, such as your email address, government issued ID, or date of birth, before providing a substantive response to the request. Depending on your location, you may designate, in writing or through a power of attorney document, an authorised agent to make requests on your behalf to exercise your rights. Before accepting such a request from an agent, we will require that the agent provide proof you have authorised them to act on your behalf, and we may need you to verify your identity directly with us.

In addition, you may have the right to appeal our decision regarding a request related to these rights by contacting us using the information provided below. When you submit a request or launch an appeal, we will limit our collection of your information to only what is necessary to securely fulfil your request or process your appeal. We will not require you or your authorised agent to pay a fee for the verification of your request or appeal.

European Residents

Data Transfers

We are based in Australia. If you are using the Services from outside Australia, please be aware that the information we collect from you may be transferred to, stored, and processed in countries outside your country of residence, including:

Australia (Sydney region): Firestore database storage and Cloud Functions hosting the TrenchCalc APIs.
United States: Firebase Authentication infrastructure, Google/Apple identity services, RevenueCat, Stripe, Resend, Formsubmit, and Vercel’s platform operations.
European Union: Open-Meteo (Germany) for weather data and selected CDN/edge locations (including Vercel and Google reCAPTCHA).

We implement contractual and organisational safeguards (including Data Processing Agreements, Standard Contractual Clauses where applicable, vendor due diligence, and data minimisation) and comply with the Australian Privacy Act 1988 and the GDPR.

Data Subject Rights

If you are located in the EEA or the UK, you have certain rights in relation to your personal data. Please note that a number of these rights only apply in certain circumstances, and all of these rights may be limited by law. To exercise any of these rights, you can contact us at the email address provided in the "Contact Us" section below:

Access: You have the right to access the personal data we hold about you, and to obtain information about how we use it, and who we share it with.
Portability: You have the right to receive a copy of the personal data we hold about you and to request that we transfer it to a third party, in certain circumstances and with certain exceptions.
Correction: You have the right to correct any of your personal data we hold that is inaccurate.
Erasure: In certain circumstances, you have the right to delete the personal data we hold about you.
Restriction of processing to storage only: You have the right to require us to stop processing the personal data we hold about you, other than for storage purposes, in certain circumstances.
Objection: You have the right to object to our processing of your personal data in certain circumstances.
Objection to marketing: You can object to marketing at any time. Please note that we do not send marketing communications.
Withdrawal of consent: Where we rely on consent to process your personal data, you have the right to withdraw this consent at any time by contacting us at the email address provided below.
Complaints: You have the right to complain to your local data protection authority about how we process your personal data. We hope you will contact us first so we can resolve any issues.

You may lodge a complaint with your local EU/EEA supervisory authority or, if you are in the United Kingdom, with the Information Commissioner’s Office (ICO) at ico.org.uk.

Legal Basis for Processing (GDPR)

Our processing activities and their corresponding lawful bases under Article 6 GDPR are summarised below:

Processing activity	Purpose	Lawful basis
Account creation, authentication (Firebase, Apple/Google)	Provide access to the app and manage your account	Contract (Art. 6(1)(b))
Company profile, seat management, usage quotas	Deliver subscription features and administer business seats	Contract / Legitimate interest (service operation)
In-app and website subscriptions (RevenueCat, Stripe)	Process purchases, billing, and entitlements	Contract (performance of the subscription agreement)
Weather information (Open-Meteo)	Provide cement placement advisory	Legitimate interest (improving safety and utility)
Transactional emails and support (Resend)	Send verification, password resets, support replies	Contract / Legitimate interest
Compliance and record keeping (Stripe, financial records)	Meet tax, accounting, and legal obligations	Legal obligation (Art. 6(1)(c))
Anonymous analytics/diagnostics (only if enabled by you)	Improve stability and performance	Consent (where analytics are expressly enabled)

Data Security

We implement industry-standard security measures to protect your data:

Encryption: All communications with our servers are encrypted using HTTPS/TLS
Authentication: Firebase Authentication (Google) with industry-standard security practices
Access Controls: Role-based access control for all data
Secure Storage: All data stored with encryption at rest
Regional Configuration: Firestore and Cloud Functions are deployed in Australia (Sydney region) while certain Firebase services (such as Authentication and Hosting CDN) operate on global infrastructure

Data Processors & International Transfers

The table below summarises the key third-party services we rely on, what data they handle, where processing may occur, and the primary safeguards or agreements that govern the transfers. All links point to the relevant privacy policies or data-processing terms.

Service	Purpose & data handled	Processing locations	Safeguards / references
Firebase (Google)	Authentication, Firestore data (company profiles, quotas), Cloud Functions, hosting/CDN logs.	Australia (Sydney) for Firestore/Functions; global (incl. United States) for Auth/CDN.	Privacy · Google Cloud DPA / SCCs.
RevenueCat	Subscription status, purchase/renewal events, user identifier/email to sync entitlements.	United States.	Privacy · DPA (SCCs).
Stripe	Website seat payments, customer/subscription IDs (Stripe stores card/payment details).	United States & global infrastructure.	Privacy · Stripe DPA / SCCs.
Open-Meteo	Weather forecasts using latitude/longitude supplied by the app.	European Union (Germany).	Terms & Privacy (GDPR-compliant processing; no persistent identifiers stored).
Resend	Transactional email (verification, notifications, support replies).	United States.	Privacy · Resend DPA (SCCs).
Formsubmit	Routes contact form submissions to our support inbox (no storage on their servers).	United States.	Privacy (SCCs available on request from Formsubmit).
Google reCAPTCHA	Spam/bot detection for sign-up and contact flows (device/usage telemetry).	Global infrastructure (including United States and EU).	Privacy · Google SCCs.
Vercel	Hosting for marketing site and API edge network (logs, traffic metadata).	Global edge network (including United States and EU).	Privacy · Vercel DPA / SCCs.
Apple & Google App Stores / Sign-In	Account authentication tokens, App Store / Play Store purchase receipts.	Global (per Apple and Google infrastructure).	Apple Privacy · Google Privacy (processed as independent controllers under their terms).

Transfers to these providers rely on Standard Contractual Clauses (SCCs), data-processing addenda, or the provider’s own GDPR-compliant terms as linked above. We continue to review these agreements and update them as providers release new versions (e.g., EU/UK addenda).

Third-Party Retention Summary

Firebase (Google): Retains authentication logs and backups per Google’s standard schedules. We delete your Auth/Firestore records at account deletion; residual backups expire per Google policies.
RevenueCat: Keeps subscription and entitlement data until we delete it via API or close the account, to maintain purchase history and support.
Stripe: Retains payment and transaction records for as long as needed to meet financial, tax, and anti-fraud obligations (typically 7+ years).
Open-Meteo: Processes latitude/longitude in real time for forecasts and does not retain personal identifiers.
Resend: Stores transactional email metadata/content only as needed to deliver messages and meet legal requirements.
Formsubmit: Forwards contact form contents to us and does not store them on its servers.
Google reCAPTCHA / Vercel: Collect telemetry/traffic metadata as described in their policies for security and operations, following their own retention schedules.

We implement additional safeguards by executing the linked data-processing agreements, reviewing each provider’s security posture, limiting shared data to the minimum necessary, and continuously monitoring for changes in processing locations or legal requirements (including APP 8, GDPR/UK GDPR, and other cross-border frameworks).

Automated Decision-Making

Under the Australian Privacy Principles (APPs), including upcoming amendments effective December 2026, entities must disclose when they use computer programs that rely on personal information to make decisions that could significantly affect individuals' rights or interests. TrenchCalc uses automated, rule-based systems for subscription and access control. We disclose the following:

How we use automated systems:

Purchase entitlement: Your entitlement is determined automatically from your app store purchase records (via RevenueCat) and, for signed-in users, from our database. Our systems use your user identifier and purchase data to decide whether you have the Free plan or the Lifetime unlock, and therefore which features you can access. This can significantly affect what you can do in the app.
Seat-based (B2B) access: For business accounts, your effective tier and feature access can be determined by seat assignment (e.g. hasSeatAccess, seatTier) in addition to or instead of a direct subscription. Our systems automatically compute your tier from stored seat and subscription data and apply the same feature and quota rules.

These systems are rule-based (not AI or machine learning). They use personal/account data solely to enforce subscription terms and feature access, and we have no additional automated decision-making features planned on our roadmap. If you have concerns about how these automated decisions affect you, you may contact us at support@engsitetools.com or lodge a complaint with the Office of the Australian Information Commissioner (OAIC).

We are monitoring the Australian Government’s proposed Privacy Act reforms scheduled for finalisation by December 2026 (including the new right to erasure, statutory tort, and enhanced civil penalties) and will update this policy before those changes take effect.

Children's Privacy

TrenchCalc is designed for engineering professionals and is not intended for children under 16 years of age (or the equivalent minimum age in your jurisdiction). We do not knowingly collect personal information from children under that age. If you believe we have collected information from a child under the applicable minimum age, please contact us immediately at support@engsitetools.com and we will delete such information.

Data Breach Notification

In the event of a data breach that affects your personal information, we will:

Notify affected users as soon as reasonably practicable
Notify the Office of the Australian Information Commissioner (OAIC) within 72 hours where required under the Notifiable Data Breaches scheme
Notify relevant data protection authorities in other jurisdictions where required by law
Provide details about the breach and recommended mitigation steps

Changes to This Policy

We may update this privacy policy from time to time to reflect changes in our practices or applicable laws. We will notify you of significant changes through the app or via email. The "Effective Date" at the top of this policy indicates when it was last updated. Continued use of TrenchCalc after changes constitutes acceptance of the updated policy.

Privacy Complaints

If you have concerns about how we handle your personal information or believe we may have breached privacy laws, you can lodge a complaint with us:

Privacy Contact: Vincent Zheng — privacy@engsitetools.com
Email: support@engsitetools.com
Subject: Please include "Privacy Complaint" in your email subject line

We will investigate your complaint and respond to you within 30 days. If you are not satisfied with our response, you have the right to escalate your complaint to the relevant data protection authority in your jurisdiction:

Australia: Office of the Australian Information Commissioner (OAIC) — www.oaic.gov.au
United Kingdom: Information Commissioner's Office (ICO) — ico.org.uk
European Union: Your local data protection authority (DPA)
United States: Federal Trade Commission (FTC) — www.ftc.gov

Contact Us

If you have any questions or concerns about this privacy policy or wish to exercise your privacy rights, please contact us at:

Entity: Vincent Zheng (trading as EngSiteTools)
ABN: 49 868 421 517
Address: 202/37 Barrack Street, Perth WA 6000, Australia
Email: support@engsitetools.com

Thank you for using TrenchCalc. We are committed to protecting your privacy.

TrenchCalc Privacy Policy