Silt Lab Zone

Sediment and soil analysis for Chubu region projects

Silt Lab Zone operates a full-service analytical laboratory in Nagoya, providing sediment, water, and soil analysis for environmental consultancies, civil engineering firms, and municipal clients across the Chubu region.

Full-spectrum laboratory testing for environmental consultancies, civil contractors, and municipal water authorities. Results delivered within five business days as standard.

Silt Lab Zone was established in Nagoya in 2014 by Kenji Matsumoto, who had spent the previous nine years as a senior analyst at the Chubu Regional Environmental Research Institute. The immediate trigger was a gap he kept encountering: small and mid-sized civil engineering firms in Aichi and Gifu prefectures needed reliable sediment data for river-improvement and flood-control projects, but the large commercial labs in Tokyo and Osaka had turnaround times of three weeks and no interest in projects below a certain contract value. Matsumoto opened a 120-square-metre facility in Nishi-ku with two colleagues, a Malvern laser diffractometer, and a commitment to returning results in five days.

The first two years were almost entirely grain-size work for contractors on the Shonai River improvement scheme. That narrow focus turned out to be useful: by 2016 the team had processed over 4,000 sediment samples from that single catchment and had built a reference dataset that no other lab in the region could match. The scope expanded gradually. Water quality testing was added in 2017 after a request from Nagoya City's waterworks division. Soil contamination screening under the Soil Contamination Countermeasures Act followed in 2018, when a long-term client began taking on brownfield redevelopment work in the Tokai industrial corridor. Each addition came from a client need, not from a strategic plan to grow the service list.

Why clients return to Silt Lab Zone

All testing done in-house

Every sample is processed in our Nagoya facility. We do not subcontract to third-party labs, which means chain-of-custody is unbroken and you speak directly with the analyst who ran your test.

JIS-compliant reporting

Reports follow JIS A 1204, JIS K 0102, and relevant Ministry of the Environment notification standards. Each report includes the raw data tables, not just summary values.

Five-day standard turnaround

Standard results are issued within five business days of sample receipt. Rush processing (two business days) is available for time-critical site investigations.

News & Announcements

2025-01-26

How to collect and package sediment samples for laboratory submission in Japan

Sediment sampling is where a study succeeds or fails, and the margin for error is smaller than most field teams expect. A core collected at the correct depth, preserved at the correct temperature, and labelled with sufficient traceability will yield data that holds up under regulatory scrutiny. A core collected carelessly — wrong container material, broken cold chain, ambiguous field notation — produces results that are either unusable or legally indefensible. In Japan, submissions to analytical laboratories are governed by a specific combination of JIS standards and Ministry of the Environment (環境省) guidance documents, and laboratories such as Silt Lab Zone evaluate incoming samples partly on the quality of the field record before analysis even begins. This guide covers the complete chain from site preparation to laboratory receipt, with enough specificity to be useful in the field.

2025-11-17

Soil Contamination Countermeasures Act: what the 26 designated substances are and how they are tested

Japan's Soil Contamination Countermeasures Act (土壌汚染対策法, abbreviated SCCA) has been in force since 2003 and substantially amended in 2010 and again in 2017. For anyone managing a site closure, redeveloping former factory land, or responding to a municipal investigation order, the law's scope is not always intuitive. It designates exactly 26 hazardous substances, assigns each substance to one of three categories depending on how it behaves in soil, and prescribes specific analytical methods for each. Getting those distinctions right determines how a site is classified, what remediation obligation follows, and what costs a landowner or tenant faces. This article walks through the statute's logic, names every designated substance, and explains the two primary test protocols — elution testing and content testing — so that the obligations are legible before you engage a certified investigator.

2026-07-05

Laser diffraction versus hydrometer method: choosing the right grain-size technique for your sediment

Grain-size analysis sits at the foundation of nearly every sediment characterisation study, and the choice of method shapes the data you get long before any calculation begins. Laser diffraction instruments like the Malvern Mastersizer have become the default in many laboratories over the past two decades, largely because they are fast, reproducible, and require small sample masses. But the hydrometer method, standardised under ASTM D422 and ISO 17892-4, has not been displaced — it remains the legally recognised procedure in many geotechnical and environmental regulatory contexts, and it behaves differently enough from optical diffraction that treating the two as interchangeable leads to real interpretive errors. This article works through the physical principles behind each technique, the sediment types and project conditions where one outperforms the other, and the practical steps needed when you must reconcile data from both methods in a single dataset.

Common questions

Q01

How do I submit samples to Silt Lab Zone?

You can drop samples off directly at our Nishi-ku facility during business hours (Monday to Friday, 8:30 to 17:30). We can also arrange courier collection for larger submissions or for clients outside Nagoya. Sample containers and submission forms are available on request by email or phone. Please do not submit samples without a completed submission form, as this delays processing.

Q02

What is the minimum sample quantity required for grain-size analysis?

For combined sieve and laser diffraction analysis, we require a minimum of 200 grams of dry sediment or 500 grams of wet sediment. For fine-grained samples (predominantly silt and clay), 100 grams dry weight is sufficient for the laser diffraction stage alone. If you are unsure whether your sample volume is adequate, contact us before dispatching.

Q03

Can you issue results in English for international project reporting?

Yes. We can issue reports in English on request at no additional charge. The data tables, parameter names, and regulatory threshold comparisons are all translated. Please specify English reporting on your submission form. Note that regulatory references will still cite Japanese standards (JIS, Ministry of the Environment notifications), as these are the applicable standards for work conducted in Japan.