engsitetools

TrenchCalc Privacy Policy

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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 subscription 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. Our AI-powered Site Diary feature uses OpenAI to generate entries from your voice recordings—your transcript, project name, location, and date are sent to OpenAI's servers in the United States. 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

Table of Contents

Information We Collect

How We Collect Information

We collect personal information in the following ways:

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:

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

Payments

Weather Data

AI Processing

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 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:

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.

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:

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.

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:

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.

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:

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:

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)
AI Site Diary (OpenAI) Generate diary entries from transcripts, project, date, location Consent (you trigger this feature)
Weather information (Open-Meteo) Provide cement advisory and diary weather context 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:

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.
OpenAI AI Site Diary (voice transcript, project name, date, location) for diary generation. United States. Privacy · API Data Processing Terms (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

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:

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:

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:

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:

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.

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