Civil Engineering: desk report

The rule

Code computed the rating from the assessor's inputs:

impact_likely=yes -> 2

Set by the rule

Decision

Released with flags

The engine's reasons

• Agencies not in the register or the evidence: Ohio EPA, USACE, Carroll County, Harrison Township Trustees
• The core evidence supports presence, peripheral extent and category 2. Problems: an unsourced 15–25 percent grading band, Fescue Road haul-route content that belongs in EG-03, avoidable labelled 'yes' when the rationale describes mitigation, and an unsupported link between the NWP 14 quote and the S-4 access road.

Evidence state

VERIFIED · field study or agency determination

The assessor's comments

Slopes reach 18 percent in the East Block and Sallow Creek valley walls. 9 of 30 test piles met refusal before 8 feet, mostly on West Block ridges. Soils show moderate corrosivity; groundwater may be near the surface in the floodplain. About 14 acres of array rows lie in the flood fringe. Fescue Road needs temporary widening.

Worst case

If what is pending at the cut-off went badly, the same rule gives a higher rating.

• Present: yes

  Geotechnical field study reports slopes up to 18 percent, refusal in 9 of 30 test piles, groundwater that may be near the surface in the floodplain, and moderate corrosivity to buried steel (C-b3cb8c76ac, C-e04f4cf7e1, C-05146fd25c, C-d1c044dc6c). Drainage memo reports slow-infiltration C/D soils and array rows in the flood fringe (C-55cbc4b507, C-546dd83365).

  Cites C-b3cb8c76ac, C-e04f4cf7e1, C-05146fd25c, C-d1c044dc6c, C-55cbc4b507, C-546dd83365

• Extent: peripheral

  Maximum measured slope is 18 percent, within the 15 to 25 percent grading-cost band, not unbuildable ground (C-b3cb8c76ac); the 25 percent figure is the row guidance for unbuildable slopes, not from a cited document. Refusal affected 30 percent of test piles, mostly on West Block ridges, not shown to cover most of the site (C-e04f4cf7e1). About 14 acres of arrays are in the flood fringe, and the soft floodplain soils are outside the layout (C-546dd83365, C-39dffbad33). The 165 acres of undermined ground is a geologic hazard rated elsewhere (C-d106c90db2).

  Cites C-b3cb8c76ac, C-e04f4cf7e1, C-546dd83365, C-39dffbad33, C-d106c90db2

• Avoidable: yes

  Conditions are addressable by standard engineering: pre-drilled or driven piles, corrosion allowance for moderate corrosivity, drainage design, and layout away from the soft floodplain (C-e04f4cf7e1, C-d1c044dc6c, C-39dffbad33). Only about 96 of the 780 fenced acres will be graded (C-4c4d92f167).

  Cites C-e04f4cf7e1, C-d1c044dc6c, C-39dffbad33, C-4c4d92f167

• Pathway: standard

  Grading of about 96 acres requires an SWP3 (C-4c4d92f167). The S-4 access road crossing fits NWP 14 without pre-construction notification (C-336bf30d1a). Array rows in Zone AE imply floodplain review (C-546dd83365). All routine approvals; no individual or prohibitive pathway.

  Cites C-4c4d92f167, C-336bf30d1a, C-546dd83365

• Impact likely: yes

  A typical build likely needs grading on slopes up to 18 percent, pile refusal mitigation on West Block ridges, array rows in the flood fringe and temporary widening of Fescue Road (C-b3cb8c76ac, C-e04f4cf7e1, C-546dd83365, C-8172eb7213).

  Cites C-b3cb8c76ac, C-e04f4cf7e1, C-546dd83365, C-8172eb7213

Supporting statements (11)

Each claim the row cites: the statement in the assessor's words, then the quote the engine found on the page.

1. C-05146fd25c

   Free water was met at 6 to 14 feet in 9 borings, mostly perched near Sallow Creek; seasonal high groundwater may be near the surface in the floodplain.

   Seasonal high groundwater may be near the surface in the floodplain.

   Preliminary Geotechnical Engineering Report - Tamsin Ridge Solar and Storage Project · DR-0018 · Page 1 · 2023-05-15

   Source field_study · Claim type presence · Polarity presence · Confidence medium · Quote check exact, 100 of 100

   Cited by EN-08 · Filed under EG-01, EN-08

   See it on page 1, claim C-05146fd25c

2. C-336bf30d1a

   The S-4 access road crossing is the only planned fill: about 40 linear feet of ephemeral channel (0.02 acre) under NWP 14.

   about 40 linear feet of ephemeral channel (0.02 acre), within NWP 14 without pre-construction notification.

   Wetland and Stream Delineation Report - Tamsin Ridge Solar and Storage Project · DR-0013 · Page 3 · 2023-05-22

   Source consultant_memo · Claim type extent · Polarity presence · Confidence high · Quote check exact, 100 of 100

   Cited by AQ-01, PE-03 · Filed under AQ-01, EG-01, PE-03

   See it on page 3, claim C-336bf30d1a

3. C-39dffbad33

   Sallow Creek floodplain has soft alluvial soils to 5 ft and is outside the layout.

   Soft to 5 ft; outside layout

   Preliminary Geotechnical Engineering Report - Tamsin Ridge Solar and Storage Project · DR-0018 · Page 2 · 2023-05-15

   Source field_study · Claim type study_finding · Polarity neutral · Confidence medium · Quote check exact, 100 of 100

   Filed under AQ-02, EG-01

   See it on page 2, claim C-39dffbad33

4. C-4c4d92f167

   SWP3 covers a fenced area of about 780 acres, of which about 96 acres will be graded.

   The SWP3 will cover the fenced area of about 780 acres, of which about 96 acres will be graded;

   Stormwater, Floodplain and Drainage Memo - Tamsin Ridge Solar and Storage Project · DR-0019 · Page 1 · 2023-06-05

   Source consultant_memo · Claim type extent · Polarity neutral · Confidence high · Quote check exact, 100 of 100

   Cited by EG-02 · Filed under EG-01, EG-02

   See it on page 1, claim C-4c4d92f167

5. C-546dd83365

   About 14 acres of array rows are in the flood fringe on Parcels 9 and 10.

   About 14 acres of array rows are in the flood fringe (Zone AE outside the floodway) on Parcels 9 and 10,

   Stormwater, Floodplain and Drainage Memo - Tamsin Ridge Solar and Storage Project · DR-0019 · Page 2 · 2023-06-05

   Source consultant_memo · Claim type extent · Polarity presence · Confidence medium · Quote check exact, 100 of 100

   Cited by AQ-02 · Filed under AQ-02, EG-01

   See it on page 2, claim C-546dd83365

6. C-55cbc4b507

   Soils are mostly hydrologic soil groups C and D, with moderate to high runoff potential.

   Soils are mostly hydrologic soil groups C and D (slow infiltration), so runoff potential is moderate to high.

   Stormwater, Floodplain and Drainage Memo - Tamsin Ridge Solar and Storage Project · DR-0019 · Page 1 · 2023-06-05

   Source consultant_memo · Claim type presence · Polarity presence · Confidence high · Quote check exact, 100 of 100

   Cited by EG-02 · Filed under EG-01, EG-02

   See it on page 1, claim C-55cbc4b507

7. C-8172eb7213

   Fescue Road is a narrow 16-foot township road with two 90-degree turns needing temporary widening for tractor-trailers.

   Fescue Road is a 16-foot chip-and-seal township road with narrow shoulders and two 90-degree turns where swept path analysis shows that tractor-trailers need temporary widening.

   Traffic and Access Memo - Tamsin Ridge Solar and Storage Project · DR-0020 · Page 1 · 2023-06-19

   Source consultant_memo · Claim type constraint · Polarity presence · Confidence high · Quote check exact, 100 of 100

   Cited by EG-03 · Filed under EG-01, EG-03

   See it on page 1, claim C-8172eb7213

8. C-b3cb8c76ac

   Slopes are 0 to 8 percent in the West Block and up to 18 percent in the East Block and Sallow Creek valley walls.

   Ground slopes are 0 to 8 percent in the West Block and up to 18 percent in the East Block and on the Sallow Creek valley walls

   Preliminary Geotechnical Engineering Report - Tamsin Ridge Solar and Storage Project · DR-0018 · Page 1 · 2023-05-15

   Source field_study · Claim type presence · Polarity presence · Confidence high · Quote check exact, 100 of 100

   See it on page 1, claim C-b3cb8c76ac

9. C-d106c90db2

   ODNR maps show the abandoned Elsby No. 2 underground coal mine beneath approximately 165 acres of the East Block (Parcels 9, 10 and 12).

   beneath approximately 165 acres of the East Block (Parcels 9, 10 and 12)

   Preliminary Geotechnical Engineering Report - Tamsin Ridge Solar and Storage Project · DR-0018 · Page 1 · 2023-05-15

   Source consultant_memo · Claim type presence · Polarity presence · Confidence high · Quote check exact, 100 of 100

   Cited by EN-02 · Filed under EG-01, EN-02

   See it on page 1, claim C-d106c90db2

10. C-d1c044dc6c

    Resistivity of 1,800 to 3,500 ohm-cm and pH 5.1 to 5.8 indicate moderate corrosivity to buried steel; sulfate exposure is negligible.

    indicate moderate corrosivity to buried steel; sulfate exposure is negligible.

    Preliminary Geotechnical Engineering Report - Tamsin Ridge Solar and Storage Project · DR-0018 · Page 1 · 2023-05-15

    Source field_study · Claim type presence · Polarity presence · Confidence high · Quote check exact, 100 of 100

    See it on page 1, claim C-d1c044dc6c

11. C-e04f4cf7e1

    Weathered shale and sandstone met at 4 to 11 feet; 9 of 30 test piles (30 percent) met refusal before 8 feet embedment, mostly on West Block ridges.

    Nine of the 30 test piles (30 percent) met refusal before reaching 8 feet of embedment, mostly on the West Block ridges.

    Preliminary Geotechnical Engineering Report - Tamsin Ridge Solar and Storage Project · DR-0018 · Page 1 · 2023-05-15

    Source field_study · Claim type presence · Polarity presence · Confidence high · Quote check exact, 100 of 100

    See it on page 1, claim C-e04f4cf7e1

• Complete topographic survey and grading design limiting grading on steeper East Block slopes; run more pile tests on West Block ridges.
• Obtain floodplain development review for Zone AE array rows, or shift rows out.
• Agree road-use and widening terms for Fescue Road with the township; confirm NWP 14 crossing with USACE.

Agencies