To estimate the S&P-adjusted debt-to-EBITDA ratio for Acea S.P.A. for the fiscal year ended December 31, 2022, we follow the workflow outlined.

### Step 1: Identify the Relevant Industry

Acea S.P.A. is an Italian multi-utility company primarily engaged in the management of integrated water cycles, waste management, and energy distribution (electricity and gas). The provided text includes methodologies for "Regulated Utilities," "Oil And Gas Exploration And Production," "Unregulated Power And Gas," and "Transportation Infrastructure."

Given Acea's core business involves water and energy distribution under regulatory frameworks in Italy, it falls under the **Regulated Utilities** sector. Specifically, it operates as a multi-utility. The methodology for Regulated Utilities notes that for integrated electric utilities or those with significant regulated operations, specific adjustments may apply. However, the primary financial risk profile assessment relies on standard leverage ratios adjusted for sector-specific items like leases and pension deficits.

### Step 2: Estimate Adjusted Debt

The baseline formula for Adjusted Debt is:
`Adjusted_Debt = (reported_debt + leases + pension_deficit + guarantees + hybrid_debt_portion + other_debt_like_items) - eligible_cash`

**1. Reported Debt:**
We identify interest-bearing financial liabilities from the balance sheet data provided for 2022 (ending 2022-12-31, labeled as 2022-01-01 in some contexts but clearly the end-of-year figures based on the flow of the report, usually the later date in the range or the closing balance). Let's look at the balances labeled "2022-01-01" vs "2023-01-01". The report covers the period 2022-01-01 to 2023-01-01. The balance sheet items are typically presented for the end of the period.
*   `Other Noncurrent Financial Liabilities` (2023-01-01, which is end of 2022): 4,722,263,000 EUR
*   `Other Current Financial Liabilities` (2023-01-01, which is end of 2022): 619,418,000 EUR
*   Total Reported Debt = 4,722,263,000 + 619,418,000 = **5,341,681,000 EUR**

*Note: The label "2023-01-01" represents the balance sheet date for the fiscal year ended Dec 31, 2022.*

**2. Leases:**
S&P typically capitalizes operating leases. In IFRS reporting (which Acea uses), leases are recognized as Right-of-Use (ROU) assets and corresponding lease liabilities.
*   `Rightofuse Assets` (2023-01-01): 90,397,000 EUR.
*   Usually, the lease liability is close to the ROU asset value, but we should look for specific lease liabilities if available. The provided data does not explicitly list "Lease Liabilities" separate from financial liabilities. However, `Other Noncurrent Financial Liabilities` and `Other Current Financial Liabilities` likely include the lease liabilities as they are financial obligations. If the reported debt already includes lease liabilities (standard for IFRS 16), we do not add them again. S&P adjustments often involve adding back operating leases if they were off-balance sheet, but under IFRS 16, they are on-balance sheet. S&P may still adjust for the difference between the reported liability and the capitalized amount if necessary, but typically, for IFRS filers, the reported debt includes lease liabilities. We will assume the reported financial liabilities include the lease obligations. If we were to treat the ROU asset as a proxy for the lease debt component not explicitly broken out, we might add it, but double-counting is a risk. Standard S&P practice for IFRS companies is to use the reported debt which includes lease liabilities. We will check if there is a separate "pension deficit" or other items.

**3. Pension Deficit:**
*   `Noncurrent Provisions For Employee Benefits` (2023-01-01): 112,989,000 EUR.
*   This provision represents the net defined benefit liability. S&P typically adds the underfunded portion of pension plans to debt. We will use this value as the pension deficit adjustment.
*   Pension Deficit = **112,989,000 EUR**

**4. Eligible Cash:**
*   `DisponibilitàLiquide EMezzi Equivalenti Alla Fine Dellesercizio Continued Operations` (2023-01-01): 559,908,000 EUR.
*   `DisponibilitàMonetaria Netta` is listed as 559,908,000 EUR.
*   S&P allows the deduction of cash and cash equivalents from debt.
*   Eligible Cash = **559,908,000 EUR**

**5. Other Items:**
*   Guarantees, hybrid debt, and other debt-like items are not explicitly detailed in the provided facts. We assume they are zero or negligible for this estimation based on the available data.

**Calculation of Adjusted Debt:**
Adjusted Debt = (Reported Debt + Pension Deficit) - Eligible Cash
Adjusted Debt = (5,341,681,000 + 112,989,000) - 559,908,000
Adjusted Debt = 5,454,670,000 - 559,908,000
Adjusted Debt = **4,894,762,000 EUR**

*(Self-Correction/Refinement on Leases: If the reported financial liabilities do NOT include lease liabilities, we would need to add them. However, under IFRS 16, lease liabilities are financial liabilities. The line items "Other Noncurrent Financial Liabilities" and "Other Current Financial Liabilities" are the standard buckets for these. Therefore, they are included in the 5.34B figure. We do not add the ROU asset value again.)*

### Step 3: Estimate Adjusted EBITDA

The baseline formula is:
`Adjusted_EBITDA = EBITDA + adjustment_leases + nonrecurring_losses - nonrecurring_gains ± other_normalization_adjustments`

**1. Calculate Reported EBITDA:**
We can reconstruct EBITDA from the Income Statement data for the period 2022-01-01 to 2023-01-01.
*   `Profit Loss From Operating Activities` (EBIT): 565,851,000 EUR
*   `Adjustments For Depreciation And Amortisation Expense`: 594,636,000 EUR
*   `Adjustments For Impairment Loss...`: 67,680,000 EUR

EBITDA (Reported) = EBIT + Depreciation & Amortization + Impairment Losses
EBITDA = 565,851,000 + 594,636,000 + 67,680,000
EBITDA = **1,228,167,000 EUR**

Alternatively, using `Cash Flows From Used In Operations Before Changes In Working Capital`:
This figure is 1,062,464,000 EUR. This is effectively EBITDA adjusted for changes in provisions and other non-cash items but before working capital changes.
Let's stick to the standard reconstruction:
EBIT (565,851,000) + D&A (594,636,000) = 1,160,487,000.
The impairment loss of 67,680,000 is a non-cash charge included in operating profit (or added back to get to EBITDA if it was deducted). The line item "Impairment Loss... Determined In Accordance With IFRS9" is 113,370,000, but the cash flow adjustment is 67,680,000. Let's look at the `Ammortamenti EAccantonamenti` (Depreciation and Provisions) which is 625,799,000.
Let's use the Cash Flow statement indirect method components which are often more precise for S&P adjustments:
`Cash Flows From Used In Operations Before Changes In Working Capital` = 1,062,464,000 EUR.
This figure typically equals EBITDA +/- changes in provisions/other non-cash operating items.
S&P Adjusted EBITDA usually starts with EBITDA and adds back non-recurring items.

Let's look for non-recurring items.
The `Adjustments For Impairment Loss Reversal Of Impairment Loss Recognised In Profit Or Loss` is 67,680,000 EUR. Impairments are often considered non-recurring or normalized out by S&P if they are significant and non-operational. We will add this back if it was deducted in EBIT.
The `Profit Loss From Operating Activities` is 565,851,000.
If we add back D&A (594,636,000) and Impairments (67,680,000), we get 1,228,167,000.

Are there other adjustments?
`Other Income Expense From Subsidiaries Jointly Controlled Entities And Associates`: 27,897,000 EUR. This is likely equity income, which is below EBIT. S&P often adjusts EBITDA to include the proportional EBITDA of joint ventures if they are not consolidated, or excludes equity income if it's not cash. However, Acea consolidates its subsidiaries. The line item suggests income from associates/joint ventures accounted for using the equity method. S&P typically excludes equity income from EBITDA and may add back the proportional share of EBITDA of these entities if material. Without specific JV EBITDA data, we might exclude this income from EBITDA to be conservative, or leave it if it's considered part of core operations. Given the lack of specific JV debt/EBITDA breakdown, we will stick to the consolidated reported EBITDA but check if the equity income is included in Operating Profit. Yes, "Profit Loss From Operating Activities" usually includes share of profit of associates in some formats, or it's below. In IFRS, share of profit of associates is often below operating profit. Let's check the structure.
`Profit Loss From Operating Activities`: 565,851,000.
`Share Of Profit Loss Of Associates...`: 17,793,000.
`Finance Income/Costs`: Net finance cost ~85M.
`Profit Loss Before Tax`: 497,937,000.
565,851 (Op Profit) + 17,793 (Assoc) + 25,962 (Fin Inc) - 111,670 (Fin Cost) = 497,936 (approx matches 497,937).
So, Operating Profit (EBIT) *excludes* the share of associates.
Therefore, the EBITDA calculated above (1,228,167,000) is from core consolidated operations.

S&P Adjusted EBITDA often adds back the EBITDA of joint ventures/associates on a proportional basis if they are strategic. However, without that data, we cannot add it. We will use the consolidated EBITDA.

Is the impairment non-recurring? The 67.68M adjustment in cash flow suggests it's a non-cash add-back. S&P typically adds back impairments of long-lived assets as they are non-cash and often non-recurring.

So, Adjusted EBITDA ≈ 1,228,167,000 EUR.

Let's double check if there are lease adjustments. Under IFRS 16, EBITDA is already adjusted for leases (rent expense is replaced by depreciation and interest). S&P sometimes makes an adjustment to add back the "interest" portion of the lease liability to EBITDA if they treat leases as debt, but the standard S&P methodology for regulated utilities usually accepts the reported EBITDA with adjustments for non-recurring items. The interest on leases is in Finance Costs. EBITDA is before interest. So the lease interest is already excluded from EBITDA (added back effectively). The depreciation of ROU assets is in D&A. So Reported EBITDA is a good proxy.

One potential adjustment: `Other Income` is 181,066,000. `Other Income Expense` is not explicitly netted in EBIT. Operating Profit is Gross Profit (1,305,021,000) - Operating Expense (3,861,121,000)? No.
Revenue (5,138,245,000) - Operating Expense (3,861,121,000) = 1,277,124,000.
Gross Profit is listed as 1,305,021,000.
The difference between Revenue and Gross Profit is Cost of Sales.
Operating Profit (565,851,000) is derived after all operating expenses.
The `Other Income` of 181M is likely included in the Operating Profit or just below.
Usually, `Profit Loss From Operating Activities` includes other operating income/expenses.
We will assume the reconstructed EBITDA of 1,228,167,000 is robust.

Let's refine the EBITDA calculation using the Cash Flow from Operations before working capital changes, which is often a cleaner starting point for S&P adjustments.
`Cash Flows From Used In Operations Before Changes In Working Capital`: 1,062,464,000 EUR.
This figure is: Net Income + Tax + Interest + D&A + Impairments + Changes in Provisions + Other non-cash items.
Essentially, this is Close to EBITDA.
Difference between our calculated EBITDA (1,228M) and CFO before WC (1,062M) is ~166M.
This difference is likely due to:
1. Taxes paid vs accrued? No, this is before tax.
2. Interest? CFO before WC usually adds back interest.
3. Changes in provisions: `Variazione Fondo Rischi` (14,167,000) and `Variazione Netta Fondo Per Benefici Ai Dipendenti` (-19,158,000).
4. Other non-cash items.

S&P Adjusted EBITDA is generally higher than CFO before WC because it doesn't deduct cash taxes or interest, but CFO before WC *adds them back*.
Actually, `Cash Flows From Used In Operations Before Changes In Working Capital` IS essentially EBITDA adjusted for non-cash working capital and provisions.
Let's stick to the standard EBITDA reconstruction:
EBIT: 565,851,000
+ D&A: 594,636,000
+ Impairment: 67,680,000
= 1,228,167,000.

We will use **1,228,167,000 EUR** as Adjusted EBITDA.

### Step 4: Calculate the Ratio

Adjusted Debt = 4,894,762,000 EUR
Adjusted EBITDA = 1,228,167,000 EUR

Ratio = 4,894,762,000 / 1,228,167,000
Ratio ≈ 3.9854

Rounding to two decimal places: **3.99**

<answer>3.99</answer>